Day :
- Smart Material Science and Technology, Smart Materials in Aviation and Defense & Innovations in Physical and Chemical Properties of Smart Materials
Chair
A S Khanna
IIT Bombay, India
Session Introduction
Lidong Zhang
New York University Abu Dhabi, United Arab Emirates.
Title: Photogated motility in smart actuators with dual response
Time : 12:45-13:15
Biography:
Dr. Lidong, Zhang now is a postdoctoral associate of material chemistry in Professor Naumov group, in New York University Abu Dhabi. His current research interests focus on novel smart polymer hydrogel actuators for energy transfer, biosensor and soft robot. He got his PhD from Pusan National University Korea, where he was working on smart polymer hydrogels for drug delivery, mineralization and catalysis under guidance of Professor Il Kim.
Abstract:
Humidity-driven motion is a fundamental process of energy conversion that is Essential for applications which require contact less actuation in response to the day-night rhythm of atmospheric humidity. In this work we demonstrate that mechanical bistability caused by rapid and anisotropic adsorption and desorption of water vapor by a flexible dynamic element which harnesses the chemical potential across very small humidity gradients for perpetual motion can be effectively modulated with light. A mechanically robust material capable of rapid exchange of water with the surroundings was prepared that undergoes swift locomotion in effect to periodic shape reconfiguration with turnover frequency of <150 min−1. The element can lift objects ~85 times heavier and can transport cargos ~20 times heavier than itself. Having an azobenzene-containing conjugate as a photoactive dopant, this entirely humidity-driven self-actuation can be controlled remotely with ultraviolet light, thus setting a platform for a new generation of smart biomimetic hybrids. The actuating material can operate in the dark and could be utilized to convert the humidity into electrical power in low-power devices driven by humidity and/or light.
A S Khanna
IIT Bombay, India
Title: Inorganic-organic hybrid based Smart Coatings
Time : 14:00-14:30
Biography:
A S Khanna is Professor at Indian Institute of Technology, Bombay, India with responsibility for teaching, research and consultancy in the field of corrosion, coatings, surface engineering and corrosion management. Prior to joining IIT Bombay in 1991, he worked in Atomic Energy and carried out R & D work at several International Labs/universities/Institutions, including Forschungszentrum Juelich (as Humboldt Fellow), Oslo University (Royal Norwegian Fellow), University de Provence, Marseille France and IHI Heavy Industry, Japan ( Fellow Japan Key Centre). Notable is his 23 years as Professor for IIT Bombay. He has guided 22 Ph.D’s and more than hundred Masters and Bachelors’ projects. He has published more than 275 papers in various National and International Journals. He is widely travelled and participated in umpteen number of conferences and meetings. He has written two books and edited 4 books. One of the book is High Performance Coatings, Woodhead publications, U.K. His professional interests focus on Coatings, Industrial corrosion prevention, surface engineering, high temperature materials. His current projects include development of smart coatings and nano-technology for enhancing paint coatings, development of grapheme and its applications in protective coatings. He is consultant / Advisor to many oil & Gas industries such as ONGC, GAIL, Reliance. In addition, he serves as Chairman for SSPC India, and is a member of NACE and ASM. He was awarded NACE Fellow in 2002 and ASM Fellow in 2005, for his contributions to the work in corrosion and coatings.
Abstract:
Inorganic-organic hybrid (IOH) coatings are the best example of eco-friendly high performance coatings. They differ from conventional coatings in several counts: use water as solvent, form chemical bond with the substrate, have superior corrosion resistance, better mechanical properties and excellent UV blocking effect. They are also considered as nano-structured coatings. The best way to synthesise them is by sol gel route. Sol-gel method starts with a hydrolysis reaction of a methoxy or ethoxy silane, followed by a condensation reaction with any functional polymer, epoxy, alkyd, polyester or urethane, provided there is an –OH group in the long chain of the monomer. The resultant precursor can then be treated with a suitable cross-linking agent to form an inorganic-organic hybrid coating. This coating can be applied on any metal substrate by spray, dipping or spin coating process after lightly activating the substrate. Such coatings were prepared in our lab using epoxy silanes, alkyds, polyurethane and polyester based monomers. These coatings showed excellent corrosion resistance much superior to the conventional coatings as well good mechanical and UV properties. These coatings were however hydrophilic in nature with a contact angle of 65-68o. An epoxy based IOH coating was then modified to a Self Cleaning Smart Coating. This was done by systematically treating the coating developed as discussed above with a set of fluorine based silanes which gave excellent hydrophobicity with a contact angle of above 110o. The coating under these conditions followed Wenzel model and in order to give it self-cleaning property, it was treated with different nano-particles, nano-ZnO and nano SiO2. A detailed treatment was then carried out to optimize the concentration of nano particles and their surface roughness and arrangement was studied using AFM and Raman spectroscopy. It was found that nano silica functionalised by a long chain polymer, gave the best sliding angle, suitable for self cleaning. This coating was found to create hydrophobicity on metal such Al, card board, paper, fabric, wood, concrete and glass. However, to use this coating as smart coating to clean glass panels in multi-storeyed buildings or solar panels in a huge solar power plant, the coating needs to be transparent. Further work was carried out using a non-fluro approach using PDMS as long chain polymer, followed by insitu generation of silica particles. This helped in creating a transparent coating with good hydrophobicity, a contact angle of 109o and a sliding angle of 25o. Detailed analysis using Raman confirmed presence of tiny nano silica particles on surface, but went under the coating after heat treatment. The coating technique also varied the properties of the coating. Spin coating under certain RPM gave the best hydrophobic and sliding effect. These coatings are now being planned to create anti-glare and anti-fog coatings. An other method to create super-hydrophobic coating was developed using functionalization of titanium oxide particles. Functionalization using PDMS was found to be the best, giving a contact angle of 150o. This, when mixed with epoxy coating showed strong super-hydrophobic behaviour. A few examples of other smart coatings developed in our lab such as self-healing coatings and conductive coatings will also be discussed.
Dennis Otibar
Ruhr-University in Bochum, Germany
Title: The effect of SMA-training on variations of production process parameters
Time : 14:30-14:45
Biography:
Dennis Otibar graduated mechanical engineer, worked at Klaus Union GmbH & Co. KG in the sales department from 2010 to 2012. Since 2013, he has been a research assistant at the Chair of Production Systems of the Institute for Product and Service Systems at the Ruhr-University in Bochum, Germany. His current research project considers the process value analysis from the production up to the application of NiTi-SMA-wires.
Abstract:
Shape memory alloys (SMA) are functional materials that can both remember a previous defined shape by thermal activation and show high elastic properties. These effects are based on a reversible, diffusion less transition between the low temperature phase (martensite) and the high temperature phase (austenite). Despite worldwide research efforts, product solutions that are based on SMA are only established in few mass-industrial applications. One main reason for this is that there are variations of industrially manufactured semi-finished SMA-products. An approach for reducing variations of the SMA-behavior due to variations in the production process can be found in the SMA-training as well. The SMA-effect reacts sensitively to even small variations of production process parameters. The aim of the investigation is to find out if variations that are caused in the wire drawing process can be compensated by SMA-training. For this purpose, NiTi-SMA-wires are drawn with different parameters and are investigated concerning their SMA-behavior such as the stress-strain or the strain-temperature curve. The training method of stress induced martensitic transformation (SIMT) is applied with different parameters regarding temperature, number of cycles, stress and time. This is followed by reinvestigations of the SMA-behavior. The before/after comparison shows if variations of production process parameters can be influenced by the SIMT-training method. First results of this project are presented within both the full paper and the future prospects regarding the SMA production process and industrial standards.
Y Mohan
Indian Institute of Technology Madras, India
Title: Temperature dependent electrical fatigue on bulk piezoceramics
Time : 14:45-15:00
Biography:
Mohan Y is a Research scholar pursing mater studies in Department of Applied Mechanics with a specialization of Solid Mechanics at the Indian Institute of Technology Madras, Chennai, India. He had worked as a senior project assistant in National institute of ocean technology in a topic of Mechanical properties and FE modelling on syntactic foams for a period of 6 months. He did his bachelors in engineering with a specialization in Mechanical engineering from Anna University, Chennai, India in 2012. His current fields of interest are fatigue, damage mechanics, smart composites and material characterization of coupled-field problems.
Abstract:
Piezoelectric materials such as lead zirconate titanate (PZT) are a class of smart materials, which are widely used in sensors and actuators applications (e.g. aerospace, automotive and high-positioning systems etc.), due to its high electromechanical coupling. In these applications, piezoceramics may be subjected to various environments and continuous operation under complex loading conditions, which may lead to nonlinear behavior and degradation of material properties [1]. Literature about fatigue in PZT material shows a strong dependence on the applied electric field and number of cycles. The performance of PZT also dependent on temperature, hence a proper understanding of the material performance under electrical fatigue for various ambient temperatures is necessary. In this study the commercially available PZT (PIC 151 from PI Ceramics Corporation) with 10 mm diameter and 1 mm thickness samples are used. The fatigue on these samples is examined under continuous operation of bipolar cyclic electric field (±2kV/mm, 50Hz) and is exposed to an elevated thermal environment (500C, 750C and 1000C) up to 106 cycles. An experimental setup is developed to analyze the fatigue performance and to investigate the deterioration of material properties (dielectric permittivity and piezoelectric co-efficient). The output parameter such as remnant polarization, the amplitude of strain and coercive electric field from the fatigue results are analyzed. These fatigue results will be useful for material, device design using piezoceramics.
Jan Pollmann
Ruhr University Bochum, Germany
Title: Design of a locking device for an SMA driven feed axis
Time : 15:00-15:15
Biography:
Jan Pollmann has completed his diploma in mechanical engineering at Ruhr University Bochum and is currently working on his PhD as a Research Assistant at the Chair of Production Systems. He has published several papers in reputed journals regarding the use of SMA actuators in linear feed axis.
Abstract:
In a current research project, the Chair of Production Systems is examining the use of multiple modular and standardized shape memory alloy (SMA) actuators in the feed axis of a small machine tool. Three linear axes will be combined to achieve tool movements in three dimensions. Later on, these machines shall be used to manufacture small work pieces with high precision. Therefore, the axis must be qualified to handle movements in the micrometer range. In addition to investigating different measures to control the displacement of the actuators, a way to lock the axis to any desired position is needed. This enables the user to hold the axis in the same position for a period of time without heating the individual SMA actuators. Therefore the durability of the assembly will be increased. Further, this setup is beneficial for carrying out precise drilling operations and for isolating the movement of one of the three linear axes by locking down the other two. Considering the small dimensions of the axis assembly and the accompanying high demands on the manufacturing process, a simple lock bar mechanism was chosen. A brake pad is pressed against the base plate of the axis by a pressure spring. In order to deactivate the latching, the brake pad is pulled up by an SMA wire, the brake pad actuator. Afterwards the spring-powered lock bar moves under a shoulder and holds the brake pad in its upper position.
Anand Sampath
Indian Institute of Technology Madras, India
Title: Vibration energy harvesting using pzt wafers
Time : 15:15-15:30
Biography:
Anand Sampath is currently pursuing his M.S (By Research) in Solid Mechanics group in the department of Applied Mechanics, IIT Madras. He obtained his UG degree in Mechanical Engineering from Anna University Chennai, India, in 2012. His current fields of interests are Finite element modeling, Smart Materials, material characterization and coupled-field problems.
Abstract:
Piezo wafers are smart materials that exhibit electro-mechanical coupling. Piezo wafers when subjected to mechanical stress accumulate electric charge and conversely mechanical strain can be obtained by the application of electric field. Due to their intrinsic electro-mechanical coupling property, quick response time, and compactness, they are widely used in energy harvesting applications, structural health monitoring systems, Piezo Wafer Active Sensors (PWAS) and so on. In this current work, vibration energy harvesting using piezo wafer is carried out experimentally and the results are validated using a proposed numerical FE model in ABAQUS. The piezo wafer specimen (PSI-5H4E) used for the analysis has a coupling coefficient of k33 higher than k31, so for experiment, it is decided to operate in 33 coupling mode, in which the excited vibration force is applied on the poling direction of the piezo-wafer. In experiment, a uni-morph cantilever beam configuration (beam has only one piezoelectric layer attached to it) is employed, which is made to vibrate by using an exciter. In order to achieve maximum power efficiency, the cantilever beam is made to vibrate at the resonant natural frequency. The geometry of the cantilever beam plays an important role in optimizing the energy harvester’s efficiency and the power output. Hence, a study on the optimization of the cantilever beam dimension is also carried out using the FEA results obtained from ABAQUS.
Antonia Bette
Ruhr-University Bochum, Germany
Title: Activation strategies and their impact on the lifetime of SMA
Time : 15:50-16:05
Biography:
Antonia Bette is research assistant for Chair of Production Systems of the Institute for Product and Service Systems at the Ruhr-University in Bochum, Germany. She completed her Master’s degree in 2015. Her current research project regards applications of SMA-based actuator systems in aircraft interiors.
Abstract:
Shape memory alloys have the astonishing ability to remember a previous imprinted shape after deformation. Moreover, the electrical resistance is suitable for position control and prediction of fatigue of the SMA-based actuator system. Due to their advantageous properties, SMA actuators are interesting for many applications, especially if high workload, low weight, electromagnetic compatibility or integration of functions is required. Despite their advantages, the potential applications of shape memory alloys are often limited by their lifetime. Along with structural factors, the life of SMA-based actuator systems is determined by functional factors. This includes displacements, cycles, load, ambient temperature, type of connection method but also control. In industrial applications often, reason for premature failure or the limited lifetime is the wrong operation of SMA-based actuator systems. In this context, proper activation is crucial. Therefore, focus of this paper is analyzing the activation of SMA actuators. First, an overview of possible strategies for activation is given and influencing factors regarding the activation of SMA actuators are discussed. Based on this, activation strategies and important factors like activation time and current are investigated using design of experiments. With design of experiments, it is possible to investigate important factors in-depth. The results will be discussed in terms of their impact on the lifetime of SMA actuators. Finally, recommendations for proper operation of SMA actuators are given. Further studies should be done investigating further factors influencing the lifetime of SMA actuators like the impact of control.
S Sreenivasa Prasath
Indian Institute of Technology Madras, India
Title: Experimental characterization of rate dependent non-linear behavior on macro-fiber composites
Time : 16:05-16:20
Biography:
S Sreenivasa Prasath is pursuing Ph.D. in the Department of Applied mechanics at Indian Institute of Technology Madras, India. He has obtained under graduate program in Aeronautical Engineering from Kumaraguru College of Technology Coimbatore, affiliated to Anna University, India, in 2011. His current fields of interests are smart composites, Material characterization and coupled-field problems.
Abstract:
The increasing automation in automobile and aerospace engineering, lead the rapid development of flexible Macro-Fiber Composites (MFCs) for sensing and actuating applications. MFCs consist of rectangular piezoceramic fibers embedded in a polymer matrix, referred to as active layer which is sandwiched between various protective and electrode layers. The high mechanical flexibility, increased strength, reliability and environmentally sealed packaging have made MFCs favorable for applications like vibration control, structural health monitoring, and energy harvesting and structural morphing. In order to increase the utilities of the MFCs in smart structures it is necessary to understand the material behavior of MFCs. However, the data available in the literature as well as from the manufacturer is limited to linear and quasi static behavior. The piezoelectric material behavior has a significant influence of the rate of applied load and exhibits a hysteresis even for a low load. In the present work, an attempt has been made to study the performance behavior of MFCs subjected to higher electric fields at different rates. To achieve this, experiments are performed on the commercially available MFCs (M2814-P1 and M2814-P2 type MFCs) under pure electrical loading for various voltage ranges and frequencies. The coupling constants are evaluated by measuring the induced strain in the longitudinal direction by using both contact (strain gauge) and non-contact (Digital Image Correlation-DIC) type strain measurements for giving electric field. It is observed that, the voltage range and frequency have a greater influence on the coupling constants of MFC. Also, butterfly (strain vs. electric field) and dielectric hysteresis (electric displacement vs. electric field) loops are observed while operating MFCs in higher electric field.
Shih-Fu, Ou
National Kaohsiung University of applied sciences, Taiwan
Title: Application of electrical discharge coating to TiNi alloys surface treatment
Time : 16:20-16:50
Biography:
Shih-Fu, Ou obtained his Ph.D. degree in 2011 from National Taiwan university for research the anodic oxidation of titanium alloys applied in biomedical implants. Since 2013, he is assistant professor of department of mold and die in National Kaohsiung university of applied sciences. His current research is divided into three parts. The first is focused on bio-ceramic and surface modification of titanium alloys applied as implants.
Abstract:
Ti-Ni shape memory alloys (SMAs) have been commonly used in mechanical, aerospace, military applications, and biomedical engineering. In biomedical field, TiNi SMAs are served as orthodontic arch wires, surgical stents, maxillofacial implants, and bone plates because of their unique superelasticity, superior shape memory effect, excellent corrosion resistance and, low elastic modulus. Nevertheless, a disadvantage is that Ni may cause allergy for a long-term implantation in human body. It has been found that corrosion resistance of TiNi SMAs is improved by coating a titanium nitride or carbide film the alloy surfaces. This study modified the surface of the Ti-Ni SMAs by electrical discharge coating technology. Gas was chosen as the dielectric fluid to improve process efficiency and decrease environmental pollution. The modified surface comprised titanium carbide and nitride which exhibited high hardness but compromised SMAs’ shape memory recovery.
- Nano Materials and Sensors & Synthesis of Smart Materials
Location: Flamingo-2
Chair
Mogens Brøndsted Nielsen
University of Copenhagen, Denmark.
Session Introduction
Mogens Brøndsted Nielsen
University of Copenhagen, Denmark
Title: From light-controlled molecular electronics devices to solar energy storage materials
Time : 10:00-10:30
Biography:
MOGENS BRØNDSTED NIELSEN, PhD, is Professor of Organic Chemistry Department of Chemistry at the University of Copenhagen, where he teaches courses in advanced organic chemistry, heterocyclic chemistry, and supramolecular chemistry. He has published more than 100 peer-reviewed papers, monographs, and book chapters.
Abstract:
Molecular switches that can be converted between high- and low-conducting states play a central role for information storage and logic operations at the molecular level and hence for the development of molecular electronics. The 1,8a-dihydroazulene-1,1-dicarbonitrile (DHA) molecule presents an example of such a light-sensitive molecule [1]. Thus, by irradiation with light, DHA undergoes a ring-opening reaction to form a vinylheptafulvene (VHF) which in turn can return to DHA by a thermally induced ring-closure. By suitable functionalization in either the five- or seven-membered rings of DHA, the switching behavior can be finely tuned as well as the optical properties of both the DHA and VHF isomers [1]. By incorporation of sulfur end-capping groups [2], DHA molecules can be anchored to silver or gold electrodes and hence be used as molecular wires / switches for molecular electronics. This talk will present how light-controlled conductance switching has been established in different junctions [3, 4]. In addition, the higher energy of the metastable VHF isomer renders the DHA-VHF pair interesting for solar thermal energy storage systems (”solar-heat batteries”) [5]. Such systems should harvest sunlight, store the energy, and ultimately release the energy when triggered. Challenges in regard to controlled release of the energy as well as energy storage capacities will be presented.
Shingjiang Jessie Lue
Chang Gung University, Taiwan
Title: Electrospun quaternized polyvinyl alcohol nanofibers with core-shell structure and their composite in alkaline fuel cell application
Time : 10:30-11:00
Biography:
Prof. Lue obtained a B.S. and M.S. degrees from National Taiwan University, and a Ph.D. degree of Biotechnology Engineering from University of Missouri-Columbia, USA, in 1990. She joined Chang Gung University in 1996 and was promoted to a full professor in 2007. She is now the department chair of Department of Chemical and Materials Engineering at CGU. Her research interest focuses on the development of high-performance materials for separation, energy, and biotechnology applications. Prof. Lue has published nearly 65 SCI papers and 2 book chapters, given 140 conference presentations, and applied 2 patents.
Abstract:
Electrospun quaternized polyvinyl alcohol (Q-PVA) nanofibers were prepared and characterized. The as-spun nanofibers exhibited lower crystallinity than the pristine Q-PVA. The core of the fibers exhibited a more amorphous region and the outer shell contained more polymer crystals. The core-shell structure of the nanofibers provided unique ionic conduction functionality after doping with potassium hydroxide (KOH) solution. A composite consisting of 5.98% electrospun Q-PVA nanofiber mat and Q-PVA polymer matrix demonstrated enhanced ionic conductivity and suppressed methanol permeability when compared to a pristine dense Q-PVA film. Both the high conductivity and suppressed permeability were attributed to the quasi-coaxial structure of the electrospun nanofibers. The soft core of the fibers formed super ionic conductive paths, while the outer shell served as a hard sheath surrounding the amorphous core. This shell induced mass transfer resistance and created a tortuous fuel pathway that suppressed methanol permeation. Such Q-PVA composite is an effective solid electrolyte and validated using alkaline fuel cell. In a direct methanol alkaline fuel cell operated at 60°C, a peak power density of 54 mw cm–2 was obtained using the electrospun Q-PVA composite, a 12% increase compared to a cell employing a pristine Q-PVA film. These results demonstrate that super-conductive coaxial electrospun nanofibers can be prepared through a single-opening spinneret and provide an elective approach for high-performance electrolyte fabrication.
Umadevi Kandalam
Nova Southeastern University, USA
Title: A nanofibrous hydrogel for bone tissue engineering
Time : 11:15-11:45
Biography:
Umadevi Kandalam is an Assistant Professor in Department of Pediatric Dentistry, College of Dental Medicine, Nova Southeastern University, Fort-Lauderdale, FL. She obtained her Doctoral degree in biology and has been pursuing her research in the niche areas of stem cell biology, signaling mechanisms and tissue engineering. Recipient of several internal and external grants, she is currently engaged in establishing an injectable cell-scaffold system for the repair of the craniofacial defects
Abstract:
Therapeutic management of bone loss in craniofacial region as a consequence of trauma, tumor surgery or congenital malformation presents clinical challenge. Biomaterials play a role in interacting with cells in the formation of tissue. PuraMatrixTM is a commercially available self-assembled synthetic peptide hydrogel that is amphiphilic in nature. Under physiological conditions PuraMatrixTM, can instantly polymerize forming matrices providing three-dimensional architecture that facilitate cells growth.The objective of the study is to investigate the ability of this hydrogel to support the cell growth and osteogenic differentiation of human gingiva derived stem cells. Mesenchymal stem cells obtained from human gingival tissue were culture expanded. Proliferation of the cells encapsulated in PuraMatrixTM scaffold was observed at 1- 7 days. In vitro osteogenic differentiation of these cells was investigated at 1 and 2 weeks. The in vivo bone regeneration ability was analyzed by using anectopic bone formation in a rat model. PuraMatrixTM embedded cells were viable during the entire period of study. Significant increase in osteogenic marker-alkaline phosphatase (ALP) activity was observed in cell- gel constructs when compared with monolayer cultures. Notably cells in PuraMatrixTM showed significant up regulation of other marker genes such as collagen type 1 and osteopontin at 2 weeks of culture. Within four weeks after implantation, osteoid like structures were observed in rats. The study revealed that PuraMatrixTM scaffold enhances the ability of HGMSCs for bone regeneration
Shiquan Tao
West Texas A&M University, United States.
Title: Sol-gel derived nanomaterials for designing fiber optic gas sensors
Time : 11:45-12:15
Biography:
Dr. Shiquan Tao completed his PhD in chemistry from Hiroshima University, Japan. He is an associate professor of chemistry at West Texas A&M University with research interest in the development of fiber optic chemical/biochemical sensors for monitoring industrial processes, environmental monitoring as well as for quick detecting foodborne pathogens. Before joining the faculty at WTAMU, he was a research faculty at the Diagnostic Instrumentation and Analysis Laboratory of Mississippi State University in charge of the institute’s fiber optic sensor research program for US DOE’ Office of Science’s Environmental Management Program.
Abstract:
Sol-gel methods and sol-gel combined with micelle techniques have been developed for synthesizing nanostructured materials, including porous silica, porous tin oxide, silver nanoparticles immobilized porous silica and palladium nanoparticles immobilized porous silica. These nanostructured materials have been used in the development of fiber optic gas sensors. The sol-gel derived porous silica has been coated on surface of optical fiber core for the development of a moisture sensor. Sol-gel derived tin oxide nanoparticles have been coated on surface of a silica optical fiber having a gold jacket for sensing reducing gases (H2, CH4, CO) at elevated temperatures (300-800oC). Silver nanoparticles have been immobilized in sol-gel derived porous silica by using a thiol stabilizer. The silver nanoparticle immobilized porous silica has been coated on surface of silica optical fiber core. The exposure of such a nanomaterial coating to an ammonia-containing gas sample causes a decrease of light intensity guided through the fiber, which can be used as a sensing signal for monitoring ammonia concentration in gas samples. Palladium nanoparticles have been synthesized by using a micelle technique with Triton X-100. The formed palladium nanoparticles have been immobilized to sol-gel derived silica. The palladium nanoparticle immobilized sol-gel silica has been made into the form of an optical fiber by using a patented fiber fabrication method. This porous fiber has been tested for sensing trace hydrogen gas in air for applications at ambient temperature. This paper reports the methodologies of making the above mentioned nanomaterials, the structure of the fiber optic sensors and test results of using the sensors for monitoring trace gases in different gas samples.
Yongmei Zheng
Beihang University, China
Title: Bioinspired multi-gradient surface materials for water-collection/repellency
Time : 12:15-12:45
Biography:
Yongmei Zheng, is a professor at School of Chemistry and Environment, and Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, in Beihang University. Research interests are focused on biological surfaces and bioinspired surface materials with gradient multi-structures to realize the dynamic wetting-controlled functions. The integrating methods of physical, chemical, and nanotechnology are used to develop novel technique into fabrication of bioinspired surfaces. Wetting mechanisms, including water repellency or water collecting, droplet driving, ice-phobic, anti-icing and anti-frosting, are revealed at micro- and nano-level.
Abstract:
Biological surfaces with the gradient features in micro- and nanostructures display smart wettability such as spider silk, beetle back, butterfly wings, and plant leaf, etc. Since spider silk collect water in mist, taking on scene of large pearly droplets, we have revealed the mechanism of the cooperation between surface energy gradient and difference of Laplace pressure. Recently series of bioinspired fibers have been designed at micro- and nano-level by the developing novel techniques such as dip-coating, fluid-coating, tilt-angle coating, electrospun and self-assembly, to combine the Rayleigh instability. These bioinspired fibers take on unique abilities such as the capturing of extreme hanging-drop; the directional driving of tiny condensed droplets on photo or temperature responsive spindle-knots and joint; the heterostructured bead-on-string fiber for humidity response; the controlling of condensed droplets in directional transport in long range gradient spindle-knots. By integrative gradient features of surfaces between spider silk and beetle back, a kind of wettable star-shape pattern surface also realizes the effect water repellency rather than others. To develop the functional surface, the wettable gradients in different modes are fabricated on the high adhesive surface, thus the high adhesive surface realize the controlling of droplet spreading in directions. Otherwise, butterfly wing and plant leaf display water repellency and low-temperature superhydrophobicity. So, bioinspired surfaces with optimal micro- and nanostructures display distinctly anti-icing, ice-phobic and de-ice abilities. It is also demonstrated further that the oriented or asymmetric features on geometries at micro- and nano-level can generate the driving of droplets that is resulted from the surface energy gradient, in addition to the trapped-air in multi-structures at Cassie’s state. Especially, the superhydrophilic oriented-nanohaired surface exhibits the directional transport of drop as the surface is at high temperature. These studies are greatly significant to help to design the novel functional engineering surfaces.
Jacek Przybylski
Czestochowa University of Technology, Poland
Title: The influence of structural parameters upon static control performance of a flextensional transducer
Time : 12:45-13:15
Biography:
Jacek Przybylski is a specialist in applied mechanics. At the early stages of his work for the Czestochowa University of Technology his scholarly research interests included the reliability theory of mechanical objects and the fatigue theory. Over the last thirty years he has been mainly concerned with the stability and vibration of mechanical systems. During that period he has published his doctoral and postdoctoral theses and many technical papers and articles. He has also been conducting research into other subject areas, such as the theoretical and experimental investigations of vibration of the divergence-pseudoflutter systems, computer aided design of mobile cranes and resonance boxes of musical instruments as well as the interaction problems between the supports of truck cranes and the ground of particular rheological properties. In the last ten years his investigation has been focused on the influence of the piezoelectric actuation on the static and dynamic behavior of mechanical systems, including the geometrically non-linear systems. His work in the above areas has been published in a large number of various Polish and international highly reputable journals. Moreover, he has published as an author or co-author seven research monographs in the field. He is the author of curriculum-oriented textbooks, laboratory instructions and concepts of many laboratory and didactic stands for graduate and postgraduate students at various stages of higher education. For his scientific and didactic activities Polish Ministry of Science and Higher Education has awarded him two individual and three collective prizes. He has also been awarded twelve prizes by the Rector of CUT.
Abstract:
Flextensional actuators belong to a group of piezoelectric transducers of great practical importance. A typical flextensional transducer consists of a piezoceramic connected to a flexible structure which amplifies and changes the direction of the generated piezoceramic displacement. The process of designing a flextensional actuator leads to the construction of such a flexible structure, coupled to a piezoceramic element or piezoceramic stack, which maximizes the output displacement and generative force as a result of piezoelectric actuation. Hence, two goals must be well balanced during the development of new actuators, i.e. high output displacement, which requires adequate high structure compliance, and high generative force, which is obtainable for high structure stiffness. Topology optimization is a technique used for designing flextensional actuators which ensures fulfilling those two opposing requirements. Piezoelectric actuators combined with a hinge lever mechanism and described by Uchino exemplify such structures. In this paper, the effects of hinge flexibility, material properties and dimensional changes on the output displacement and the generative axial force of the flextensional transducer have been investigated. The actuator is composed of two rectilinear or initially deflected beams placed equidistantly from a centrally located piezoceramic rod. A link with a hinge strengthened by a rotational spring placed symmetrically on both ends of the structure is adopted as a flexible joint. A simplified analytical mathematical model has been developed on the basis of the stationary value of the total potential energy principle with the application of Bernoulli-Euler theory and von Karman non-linear strain-displacement relations. The numerical calculations show that the output displacement and internal axial force generated by both the externally distributed load and the electric field application can be manipulated easily by changing the actuator material, the distance between the beams and the rod, the amplitude of beam initial displacement as well as the flexibility of the hinge. To keep the piezoelectric rod compressed during the operation, the application of structure prestressing has been considered in the model and computations. The obtained results may have applications in the design process of such actuators.
Mikk Antsov
University of Tartu, Estonia
Title: Observation of shape restoration effect in core-shell nanowire structures
Time : 14:15-14:30
Biography:
Mikk Antsov is a second year PhD student and is currently working in the University of Tartu, Institute of Physics in the Laboratory of Nanostructured Materials. His current research involves the study of the mechanisms of nanoscale friction and the mechanical properties of different nanostructures. He has published 9 papers on these topics in reputed journals.
Abstract:
The combination of two different nanostructured materials into a heterostructure can lead to completely new novel properties, which for both materials separately is missing. One of the most interesting and promising structures in this field are core-shell materials, for example nanowires (NWs), where the core material (metal, oxide) is covered by a other material (metal, oxide). In this work, Ag-SiO2 core-shell NWs were fabricated using a known sol-gel method, where Ag NWs were covered with a uniform SiO2 layer. The enhanced mechanical properties were demonstrated via the cantilevered beam bending technique carried out in a scanning electron microscope. The improved fracture strength and resistance to fatigue were shown and compared to the bare Ag NWs. Under electron beam radiation a novel shape restoration effect was demonstrated and studied. To fully understand this phenomenon the core and shell materials were analysed separately. Mechanical tests were conducted on the empty SiO2 shells and on Ag NWs. The experimental conditions were simulated using the finite element method and the mechanisms behind the shape restoration and fracture resistance were proposed.
Qiaoyun Xie
University of Pittsburgh, USA
Title: Dynamic fracture toughness of TAC/CNTS/SIC CMCS prepared by spark plasma sintering
Time : 14:30-14:45
Biography:
Qiaoyun Xie, PhD, is the graduate researcher in the department of Mechanical Engineering & Materials Science at University of Pittsburgh. Her R&D areas focus on the micro and thermo-mechanical property degradation of nano particle/fiber reinforced composites at high strain rate dynamic loading conditions, and material model development to characterize the dynamic profile of energy absorption, damage initiation and propagation. Her recent work involved in the design, manufacturing and characterization of a new hybrid system of carbon nanotubes (CNTs) and TaC reinforced SiC ceramic composites to resist oxidation, dynamic impact and fracture damage, that for the application in aerospace turbine engines and space vehicles.
Abstract:
This study focuses on the dynamic fracture toughness of TaC and carbon nanotubes (CNTs) reinforced SiC ceramic matrix composites (CMCs), that prepared by a two-stage spark plasma sintering (SPS) technique. A high densification of 98.4% was achieved under the sintering parameter of 133oC/min, 1800oC and 90 MPa pressure. Vickers indentation was employed to measure the static fracture toughness on the polished surface of ceramic samples; SEM was applied to directly observe the crack propagation after indentation; and split Hopkinson pressure bar (SHPB) was developed to determine the dynamic fracture toughness within the ceramic samples subjected to an impact in a three-point bending configuration. The result indicated that, the dynamic fracture toughness for SiC ceramics was 4.71-8.36 MPa∙m1/2, which was higher that the quasi-static toughness of 3.88 MPa∙m1/2. It was found that SiC ceramics exhibited a more strain rate dependent property for higher strain rate. Fracture toughening mechanisms of CNTs deflection and CNTs bridging were directly observed by SEM.
Md Mamun Bin Ibne
University Kebangsaan Malaysia, Malaysia
Title: A contactless capacitive biosensor for muscle activity measurement
Time : 14:45-15:15
Biography:
Mamun Bin Ibne Reaz was born in Bangladesh, in December 1963. He received his B.Sc. and M.Sc. degree in Applied Physics and Electronics, both from University of Rajshahi, Bangladesh, in 1985 and 1986, respectively. He received his D.Eng. degree in 2007 from Ibaraki University, Japan. He is currently a Professor in the Department of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia, Malaysia involving in teaching, research and industrial consultation. He is a regular associate of the Abdus Salam International Centre for Theoretical Physics since 2008. He is also a Senior Member of IEEE. He has vast research experiences in Japan, Italy and Malaysia. He has published extensively in the area of IC Design and Biomedical application IC. He is author and co-author of more than 200 research articles in design automation and IC design for biomedical applications. He is also the recipients of more than 50 research grants (national and international).
Abstract:
As elderly population grows globally, the percentage of people diagnosed with musculoskeletal disorder (MSD) increase proportionally. Electromyography (EMG) is an important biosignal that contributes to MSD’s clinical diagnose and recovery process. Conventional conductive electrode has many disadvantages in the continuous EMG measurement application. This research has design a new surface EMG biosensor based on the parallel-plate capacitive coupling principle. The biosensor is developed by using a double-sided PCB with having one side of the PCB use to construct high input impedance circuitry while the other side of the copper (CU) plate function as biosignal sensing metal plate. The metal plate is insulated using kapton tape for contactless application. The result implicates that capacitive biosensor is capable to constantly capture EMG signal without having galvanic contact to human skin surface. However, there are noticeable noise couple into the measured signal. Post signal processing is needed in order to present a clean and significant EMG signal. A complete design of single ended, non-contact, high input impedance, front end EMG biosensor is presented in this paper.
- day 3
- Young Researchers Fourm
Session Introduction
Y Mohan
Indian Institute of Technology Madras, India
Title: Temperature dependent electrical fatigue on bulk piezoceramics
Biography:
Mohan Y is a Research scholar pursing mater studies in Department of Applied Mechanics with a specialization of Solid Mechanics at the Indian Institute of Technology Madras, Chennai, India. He had worked as a senior project assistant in National institute of ocean technology in a topic of Mechanical properties and FE modelling on syntactic foams for a period of 6 months. He did his bachelors in engineering with a specialization in Mechanical engineering from Anna University, Chennai, India in 2012. His current fields of interest are fatigue, damage mechanics, smart composites and material characterization of coupled-field problems.
Abstract:
Piezoelectric materials such as lead zirconate titanate (PZT) are a class of smart materials, which are widely used in sensors and actuators applications (e.g. aerospace, automotive and high-positioning systems etc.), due to its high electromechanical coupling. In these applications, piezoceramics may be subjected to various environments and continuous operation under complex loading conditions, which may lead to nonlinear behavior and degradation of material properties [1]. Literature about fatigue in PZT material shows a strong dependence on the applied electric field and number of cycles. The performance of PZT also dependent on temperature, hence a proper understanding of the material performance under electrical fatigue for various ambient temperatures is necessary. In this study the commercially available PZT (PIC 151 from PI Ceramics Corporation) with 10 mm diameter and 1 mm thickness samples are used. The fatigue on these samples is examined under continuous operation of bipolar cyclic electric field (±2kV/mm, 50Hz) and is exposed to an elevated thermal environment (500C, 750C and 1000C) up to 106 cycles. An experimental setup is developed to analyze the fatigue performance and to investigate the deterioration of material properties (dielectric permittivity and piezoelectric co-efficient). The output parameter such as remnant polarization, the amplitude of strain and coercive electric field from the fatigue results are analyzed. These fatigue results will be useful for material, device design using piezoceramics.
S Sreenivasa Prasath
Indian Institute of Technology Madras, India
Title: Experimental characterization of rate dependent non-linear behavior on macro-fiber composites
Biography:
S. Sreenivasa Prasath is pursuing Ph.D. in the Department of Applied mechanics at Indian Institute of Technology Madras, India. He has obtained under graduate program in Aeronautical Engineering from Kumaraguru College of Technology Coimbatore, affiliated to Anna University, India, in 2011. His current fields of interests are smart composites, Material characterization and coupled-field problems.
Abstract:
The increasing automation in automobile and aerospace engineering, lead the rapid development of flexible Macro-Fiber Composites (MFCs) for sensing and actuating applications. MFCs consist of rectangular piezoceramic fibers embedded in a polymer matrix, referred to as active layer which is sandwiched between various protective and electrode layers. The high mechanical flexibility, increased strength, reliability and environmentally sealed packaging have made MFCs favorable for applications like vibration control, structural health monitoring, and energy harvesting and structural morphing. In order to increase the utilities of the MFCs in smart structures it is necessary to understand the material behavior of MFCs. However, the data available in the literature as well as from the manufacturer is limited to linear and quasi static behavior. The piezoelectric material behavior has a significant influence of the rate of applied load and exhibits a hysteresis even for a low load. In the present work, an attempt has been made to study the performance behavior of MFCs subjected to higher electric fields at different rates. To achieve this, experiments are performed on the commercially available MFCs (M2814-P1 and M2814-P2 type MFCs) under pure electrical loading for various voltage ranges and frequencies. The coupling constants are evaluated by measuring the induced strain in the longitudinal direction by using both contact (strain gauge) and non-contact (Digital Image Correlation-DIC) type strain measurements for givingelectric field. It is observed that, the voltage range and frequency have a greater influence on the coupling constants of MFC. Also, butterfly (strain vs. electric field) and dielectric hysteresis (electric displacement vs. electric field) loops are observed while operating MFCs in higher electric field.
Anand S
Indian Institute of Technology Madras, India
Title: Vibration energy harvesting using pzt wafers
Biography:
Anand S is currently pursuing his M.S (By Research) in Solid Mechanics group in the department of Applied Mechanics, IIT Madras. He obtained his UG degree in Mechanical Engineering from Anna University Chennai, India, in 2012. His current fields of interests are Finite element modeling, smart materials, material characterization and coupled-field problems.
Abstract:
Piezo wafers are smart materials that exhibit electro-mechanical coupling. Piezo wafers when subjected to mechanical stress accumulate electric charge and conversely mechanical strain can be obtained by the application of electric field. Due to their intrinsic electro-mechanical coupling property, quick response time, and compactness, they are widely used in energy harvesting applications, structural health monitoring systems, Piezo Wafer Active Sensors (PWAS) and so on. In this current work, vibration energy harvesting using piezo wafer is carried out experimentally and the results are validated using a proposed numerical FE model in ABAQUS. The piezo wafer specimen (PSI-5H4E) used for the analysis has a coupling coefficient of k33 higher than k31, so for experiment, it is decided to operate in 33 coupling mode, in which the excited vibration force is applied on the poling direction of the piezo-wafer. In experiment, a uni-morph cantilever beam configuration (beam has only one piezoelectric layer attached to it) is employed, which is made to vibrate by using an exciter. In order to achieve maximum power efficiency, the cantilever beam is made to vibrate at the resonant natural frequency. The geometry of the cantilever beam plays an important role in optimizing the energy harvester’s efficiency and the power output. Hence, a study on the optimization of the cantilever beam dimension is also carried out using the FEA results obtained from ABAQUS.
- Smartness of Civil Engineering and Intelligent Structures & Smart and Biological Materials in Humans
Location: Flamingo-2
Chair
K N Hui
Pusan National University, Republic of Korea
Session Introduction
K N Hui
Pusan National University, Republic of Korea
Title: Bimetallic Pd-Pt/graphene aerogel on nickel foam as binder-free anodic electrode for electro-oxidation of ethanol
Time : 10:00-10:30
Biography:
K N Hui is an Associate Professor at the Department of Materials Science and Engineering of Pusan National University in South Korea. His current research focuses on synthesis of hierarchical carbon/graphene materials as well as on the development of 3D hierarchical metal oxide materials as advanced electrode materials for energy storage and conversion applications. His research has led to one US patent, 7 Korea patents, four review papers, three book chapters, 86 peer-reviewed SCI journal papers. He has served as guest editor/member of the editorial board of a number of journals.
Abstract:
Fuel cell is one of the most effective devices for energy conversion with low pollution characteristics that can overcome the pollution problems caused by the consumption of fossil fuels. Direct ethanol fuel cell (DEFC) is one of the most widely investigated fuel cells owing to their high efficiency, low pollutant emission, low operation temperature, ease of handing and transportation, and its non-toxic features.A green and simple method was developed to prepare Pd/Pt alloy NPs (at different ratios based on at%) loaded graphene aerogel coated on nickel foam (Pd-Pt/GA/NF) as binder-free anodic electrodes for the electro-oxidation of ethanol. The morphology, chemical composition, and electrochemical performance of the electrodes were analyzed by optical microscopy, scanning electron microscopy/energy dispersive X- ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and cyclic voltammetry. The results indicated that the Pd/Pt ratio (1:2.9, 1:1.31, 1:1.03), mean particle size, size distribution, and loading of Pd-Pt alloy NPs on GA were dependent on the initial concentration of PtCl62− ions in the synthesis. The current density and the poisoning tolerance ability of the electrodes were increased when the Pd/Pt ratio of the electrodes was changed from 1:2.9 to 1:1.03 due to the synergetic effect of the binary Pd-Pt alloy NPs on the electrode and the small particle size of Pd-Pt alloy NPs. The Pd1Pt1.03/GA/NF electrode showed good activity in the electro-oxidation of ethanol with high stability over 1000 cycles.
Shiquan Tao
West Texas A&M University, USA
Title: Immunomagnetic separation combined with enzyme linked immunosorbent assay for quick detection of Salmonella in raw eggs
Time : 10:30-11:00
Biography:
Shiquan Tao completed his PhD in Chemistry from Hiroshima University, Japan. He is an Associate Professor of Chemistry at West Texas A&M University with research interest in the development of fiber optic chemical/biochemical sensors for monitoring industrial processes, environmental monitoring as well as for quick detecting foodborne pathogens. Before joining the faculty at WTAMU, he was a research faculty at the Diagnostic Instrumentation and Analysis Laboratory of Mississippi State University in charge of the institute’s fiber optic sensor research program for US DOE’ Office of Science’s Environmental Management Program.
Abstract:
An immunomagnetic separation (IMS) method was developed for separating Salmonella bacteria from large-volume samples of raw eggs. An egg was homogenized with a blender. The homogenized egg material was diluted with a 0.05% Triton X-100 solution to make a 200 mL sample mixture. Anti-Salmonella typhimurium antibody coated magnetic micro particles (MMP) were used to trap Salmonella typhimurium bacteria in the sample mixture. The Salmonella-trapped MMP were separated from the egg sample mixture by using a large magnet. An enzyme-linked immunosorbent assay method was adopted and revised for detecting the bacteria trapped onto the MMP. Horseradish peroxidase labeled anti-Salmonella typhimurium antibody was used to label the trapped bacteria, and a SureblueTM solution was used as a substrate. The color compound resulted from horseradish peroxidase catalyzed reaction was detected with UV/Vis absorption spectrometry using a 1 cm sample cell. This simple method can detect 1.4x107 Salmonella typhimurium cells in one raw egg (7.0*104 Salmonella cells/mL in a sample mixture) without any pre-enrichment. The method is quick, can obtain test results within 5 hours. The results presented in this poster demonstrate the feasibility of using IMS for separating bacteria from large volume complex samples, which could be adopted for detecting bacteria in other type samples in food safety inspection.
Theresa O Egbuchunam
Federal University of Petroleum Resources, Nigeria
Title: Characterization and modification of clay materials, solid-phase reactions of organic molecules intercalated in clay minerals and their utilization in contaminant attenuation
Time : 11:15-11:45
Biography:
Theresa O Egbuchunam, is a scientist with a proven technical track record in teaching and research in chemistry at the tertiary level, has research experience in polymer materials, environmental pollution and control management. She is an Associate Professor of Materials Chemistry and presently a member of the Governing Council, Federal University of Petroleum Resources, Effurun, Delta State, Nigeria. She also has extensive research experience in the chemistry of polymer materials and has written and published extensively in local and international journals.
Abstract:
The substitution of cations in the interlayer region of clay with different amounts of cetyl trimethyl ammonium bromide (CTAB) was carried out with the aim of synthesizing an organoclay which represents a new class of materials that may find application in waste water treatment. Clay materials from Otedo, in Ughelli South in Delta State in Southern Nigeria, was purified and subjected to a procedure used for organoclay synthesis comprising: washing, drying, sieving, cation exchange and drying. The modified clay samples were characterized by infra-red (IR) spectroscopy, Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES), X-ray diffractometry (XRD), Scanning Electron Microscopy (SEM) and Thermogravimetric analysis (TGA). An increase, albeit slight, in the basal spacing of the modified clay material indicates the intercalation of organic moiety between the layers of kaolinite. SEM images show modification with the intercalation of the organic surfactant as there was a reduction in the clay particle size and agglomeration. The frequency shifts of the absorption bands in the ranges of 1700 – 1600 cm-1 and 3700 – 3600 cm-1 from the FTIR spectra provide additional evidence resulting from the replacement of hydrated cations (free and interlayer water) by the organic surfactant. The reduced moisture content in the organoclays as observed after thermal treatment indicates that the hydrophilicity of the surface of the kaolinite clay was greatly reduced.
Yuri Aristov
Boreskov Institute of Catalysis, Russia
Title: Smart functional adsorbents: a harmonization approach
Time : 11:45-12:15
Biography:
Yuri Aristov is a professor of physical chemistry and the head of the Group of Energy Accumu-lating Materials and Processes at the Boreskov Institute of Catalysis (BIC), Novosibirsk, Russia. He received his M.Sc. degree from the Moscow Physico-Technical Institute in 1977, and his doctoral and habilitation degrees from BIC (1984 and 2003). He contributed to the fields of radiation chemistry, low-temperature electron tunneling, fractal analysis of porous solids, and thermochemical transformation of heat. He is currently working on novel composite adsorbents for adsorptive chilling, gas drying, and maintaining relative humidity in museums. He has published 1 monograph, 200 papers, and 26 patents.
Abstract:
Adsorption phenomena are known from ancient times and still attract increasing attention for both industrial processes and everyday life. By now, numerous technological applications of adsorbents (gas/liquid separation/purification, gas storage, heat transformation, drug delivery, life support systems on a spacecraft, air conditioning, etc.) are quite advanced. Nevertheless, there is still a big room for their further improvement. In our opinion, the main direction of this improvement could be related to harmonization of the adsorbent with the specific process. Two ways of the harmonization are considered: (a) screening of already available adsorbents to select one, the properties of which fit better (even if not perfectly) the particular adsorptive process and (b) nanotailoring of a novel adsorbent with predetermined properties adapted to the given process. The main idea of the latter approach is that for each adsorptive technology (process, cycle) and its particular conditions there is an optimal adsorbent (OA), the properties of which could enable perfect performance of this process or cycle. Here, we first analyze what exactly the OA is. Quantitative requirements to the adsorbents optimal for several selected applications (gas drying, heat transformation/storage, maintaining relative humidity in museums, shifting equilibrium of catalytic synthesis, extraction of water from atmospheric air) are formulated in terms of the Dubinin adsorption potential and isobar shape. Then, we briefly consider how to synthesize a real material with adsorption properties close to those of the OA. Metal-organic frameworks, aluminophosphates and composite sorbents "salt in porous matrix" are considered as examples.
Shahria Alam
The University of British Columbia, Canada
Title: Seismic Applications of Shape Memory Alloys in Steel Buildings: A Review
Time : 12:15-12:45
Biography:
Shahria Alam is an Associate Professor in the School of Engineering at The University of British Columbia’s Okanagan campus. He received his PhD in Structural Engineering from the University of Western Ontario in 2008. His research interests include sustainable construction and smart materials for structural applications and seismic rehabilitation. He published more than 100 peer reviewed papers and is the recipient of many national and international awards. He has also delivered several keynote speeches in international conferences on smart materials. Currently he is serving as a Chair of the Concrete Structures sub-Committee of the Canadian Society for Civil Engineering (CSCE), and also a member of several international code committees.
Abstract:
Shape Memory Alloys (SMAs) are a class of metallic alloys with unique properties suitable for various civil engineering applications. SMAs are known for their capabilities to undergo large deformations while returning to their original undeformed shape through stress removal (superelasticity) or heating (shape memory effect). These desirable characteristics have attracted the interests of civil and structural engineers. Over the past three decades, several applications have been proposed and investigated for seismic response mitigation of steel buildings using SMAs in the forms of bars, wires, shells, and plates. In addition to providing supplemental damping, SMAs are used in civil infrastructures to mainly provide self-centering (i.e, return the structure back to its original position). As a result of this self-centering performance, residual deformations are eliminated in the building, even after severe earthquake events. Consequently, repair costs are significantly reduced following earthquakes. Here, a state-of-the-art review of the research on SMA-based damping and recentering devices, isolation devices, bracing systems, and structural retrofit and rehabilitations in steel braced frames and moment frames is presented. First, a general brief introduction of shape memory alloys is provided. Afterwards, the literature review is presented in three main sections, including numerical works, experimental works, and numerical studies along with experimental works. The challenges that exist for the practical applications of smart materials in buildings are also discussed. Based on the literature review, recommendations are provided for future research in this field.
- Poster
- Young Research Form
Session Introduction
Dennis Otibar
Ruhr-University Bochum, Germany
Title: The effect of SMA-training on variations of production process parameters
Biography:
Dennis Otibar graduated mechanical engineer, worked at Klaus Union GmbH & Co. KG in the sales department from 2010 to 2012. Since 2013, he has been a research assistant at the Chair of Production Systems of the Institute for Product and Service Systems at the Ruhr-University in Bochum, Germany. His current research project considers the process value analysis from the production up to the application of NiTi-SMA-wires.
Abstract:
Shape memory alloys (SMA) are functional materials that can both remember a previous defined shape by thermal activation and show high elastic properties. These effects are based on a reversible, diffusionless transition between the low temperature phase (martensite) and the high temperature phase (austenite). Despite worldwide research efforts, product solutions that are based on SMA are only established in few mass-industrial applications. One main reason for this is that there are variations of industrially manufactured semi-finished SMA-products. An approach for reducing variations of the SMA-behavior due to variations in the production process can be found in the SMA-training as well. The SMA-effect reacts sensitively to even small variations of production process parameters. The aim of the investigation is to find out if variations that are caused in the wire drawing process can be compensated by SMA-training. For this purpose, NiTi-SMA-wires are drawn with different parameters and are investigated concerning their SMA-behavior such as the stress-strain or the strain-temperature curve. The training method of stress induced martensitic transformation (SIMT) is applied with different parameters regarding temperature, number of cycles, stress and time. This is followed by reinvestigations of the SMA-behavior. The before/after comparison shows if variations of production process parameters can be influenced by the SIMT-training method. First results of this project are presented within both the full paper and the future prospects regarding the SMA production process and industrial standards.
Jan Pollmann
Ruhr University Bochum, Germany
Title: Design of a locking device for an SMA driven feed axis
Biography:
Jan Pollmann has completed his diploma in mechanical engineering at Ruhr University Bochum and is currently working on his PhD as a Research Assistant at the Chair of Production Systems. He has published several papers in reputed journals regarding the use of SMA actuators in linear feed axis.
Abstract:
In a current research project, the Chair of Production Systems is examining the use of multiple modular and standardized shape memory alloy (SMA) actuators in the feed axis of a small machine tool. Three linear axes will be combined to achieve tool movements in three dimensions. Later on, these machines shall be used to manufacture small work pieces with high precision. Therefore, the axis must be qualified to handle movements in the micrometer range. In addition to investigating different measures to control the displacement of the actuators, a way to lock the axis to any desired position is needed. This enables the user to hold the axis in the same position for a period of time without heating the individual SMA actuators. Therefore the durability of the assembly will be increased. Further, this setup is beneficial for carrying out precise drilling operations and for isolating the movement of one of the three linear axes by locking down the other two. Considering the small dimensions of the axis assembly and the accompanying high demands on the manufacturing process, a simple lock bar mechanism was chosen. A brake pad is pressed against the base plate of the axis by a pressure spring. In order to deactivate the latching, the brake pad is pulled up by an SMA wire, the brake pad actuator. Afterwards the spring-powered lock bar moves under a shoulder and holds the brake pad in its upper position.
Antonia Bette
Ruhr-University Bochum, Germany
Title: Activation strategies and their impact on the lifetime of SMA
Biography:
Antonia Bette is research assistant at the Chair of Production Systems of the Institute for Product and Service Systems at the Ruhr-University in Bochum, Germany. She completed her Master’s degree in 2015. Her current research project regards applications of SMA-based actuator systems in aircraft interiors.
Abstract:
Shape memory alloys have the astonishing ability to remember a previous imprinted shape after deformation. Moreover, the electrical resistance is suitable for position control and prediction of fatigue of the SMA-based actuator system. Due to their advantageous properties, SMA actuators are interesting for many applications, especially if high workload, low weight, electromagnetic compatibility or integration of functions is required. Despite their advantages, the potential applications of shape memory alloys are often limited by their lifetime. Along with structural factors, the life of SMA-based actuator systems is determined by functional factors. This includes displacements, cycles, load, ambient temperature, type of connection method but also control. In industrial applications often, reason for premature failure or the limited lifetime is the wrong operation of SMA-based actuator systems. In this context, proper activation is crucial. Therefore, focus of this paper is analyzing the activation of SMA actuators. First, an overview of possible strategies for activation is given and influencing factors regarding the activation of SMA actuators are discussed. Based on this, activation strategies and important factors like activation time and current are investigated using design of experiments. With design of experiments, it is possible to investigate important factors in-depth. The results will be discussed in terms of their impact on the lifetime of SMA actuators. Finally, recommendations for proper operation of SMA actuators are given. Further studies should be done investigating further factors influencing the lifetime of SMA actuators like the impact of control.
Y Mohan
Indian Institute of Technology Madras, India
Title: Temperature dependent electrical fatigue on bulk piezoceramics
Biography:
Mohan Y is a Research scholar pursing mater studies in Department of Applied Mechanics with a specialization of Solid Mechanics at the Indian Institute of Technology Madras, Chennai, India. He had worked as a senior project assistant in National institute of ocean technology in a topic of Mechanical properties and FE modelling on syntactic foams for a period of 6 months. He did his bachelors in engineering with a specialization in Mechanical engineering from Anna University, Chennai, India in 2012. His current fields of interest are fatigue, damage mechanics, smart composites and material characterization of coupled-field problems.
Abstract:
Piezoelectric materials such as lead zirconate titanate (PZT) are a class of smart materials, which are widely used in sensors and actuators applications (e.g. aerospace, automotive and high-positioning systems etc.), due to its high electromechanical coupling. In these applications, piezoceramics may be subjected to various environments and continuous operation under complex loading conditions, which may lead to nonlinear behavior and degradation of material properties [1]. Literature about fatigue in PZT material shows a strong dependence on the applied electric field and number of cycles. The performance of PZT also dependent on temperature, hence a proper understanding of the material performance under electrical fatigue for various ambient temperatures is necessary. In this study the commercially available PZT (PIC 151 from PI Ceramics Corporation) with 10 mm diameter and 1 mm thickness samples are used. The fatigue on these samples is examined under continuous operation of bipolar cyclic electric field (±2kV/mm, 50Hz) and is exposed to an elevated thermal environment (500C, 750C and 1000C) up to 106 cycles. An experimental setup is developed to analyze the fatigue performance and to investigate the deterioration of material properties (dielectric permittivity and piezoelectric co-efficient). The output parameter such as remnant polarization, the amplitude of strain and coercive electric field from the fatigue results are analyzed. These fatigue results will be useful for material, device design using piezoceramics.
Sreenivasa Prasath
Indian Institute of Technology Madras, India
Title: Experimental characterization of rate dependent non-linear behavior on macro-fiber composites
Biography:
S. Sreenivasa Prasath is pursuing Ph.D. in the Department of Applied mechanics at Indian Institute of Technology Madras, India. He has obtained under graduate program in Aeronautical Engineering from Kumaraguru College of Technology Coimbatore, affiliated to Anna University, India, in 2011. His current fields of interests are smart composites, Material characterization and coupled-field problems.
Abstract:
The increasing automation in automobile and aerospace engineering, lead the rapid development of flexible Macro-Fiber Composites (MFCs) for sensing and actuating applications. MFCs consist of rectangular piezoceramic fibers embedded in a polymer matrix, referred to as active layer which is sandwiched between various protective and electrode layers. The high mechanical flexibility, increased strength, reliability and environmentally sealed packaging have made MFCs favorable for applications like vibration control, structural health monitoring, and energy harvesting and structural morphing. In order to increase the utilities of the MFCs in smart structures it is necessary to understand the material behavior of MFCs. However, the data available in the literature as well as from the manufacturer is limited to linear and quasi static behavior. The piezoelectric material behavior has a significant influence of the rate of applied load and exhibits a hysteresis even for a low load. In the present work, an attempt has been made to study the performance behavior of MFCs subjected to higher electric fields at different rates. To achieve this, experiments are performed on the commercially available MFCs (M2814-P1 and M2814-P2 type MFCs) under pure electrical loading for various voltage ranges and frequencies. The coupling constants are evaluated by measuring the induced strain in the longitudinal direction by using both contact (strain gauge) and non-contact (Digital Image Correlation-DIC) type strain measurements for givingelectric field. It is observed that, the voltage range and frequency have a greater influence on the coupling constants of MFC. Also, butterfly (strain vs. electric field) and dielectric hysteresis (electric displacement vs. electric field) loops are observed while operating MFCs in higher electric field.
Anand S
Indian Institute of Technology Madras, India
Title: Vibration energy harvesting using pzt wafers
Biography:
Anand S is currently pursuing his M.S (By Research) in Solid Mechanics group in the department of Applied Mechanics, IIT Madras. He obtained his UG degree in Mechanical Engineering from Anna University Chennai, India, in 2012. His current fields of interests are Finite element modeling, smart materials, material characterization and coupled-field problems.
Abstract:
Piezo wafers are smart materials that exhibit electro-mechanical coupling. Piezo wafers when subjected to mechanical stress accumulate electric charge and conversely mechanical strain can be obtained by the application of electric field. Due to their intrinsic electro-mechanical coupling property, quick response time, and compactness, they are widely used in energy harvesting applications, structural health monitoring systems, Piezo Wafer Active Sensors (PWAS) and so on. In this current work, vibration energy harvesting using piezo wafer is carried out experimentally and the results are validated using a proposed numerical FE model in ABAQUS. The piezo wafer specimen (PSI-5H4E) used for the analysis has a coupling coefficient of k33 higher than k31, so for experiment, it is decided to operate in 33 coupling mode, in which the excited vibration force is applied on the poling direction of the piezo-wafer. In experiment, a uni-morph cantilever beam configuration (beam has only one piezoelectric layer attached to it) is employed, which is made to vibrate by using an exciter. In order to achieve maximum power efficiency, the cantilever beam is made to vibrate at the resonant natural frequency. The geometry of the cantilever beam plays an important role in optimizing the energy harvester’s efficiency and the power output. Hence, a study on the optimization of the cantilever beam dimension is also carried out using the FEA results obtained from ABAQUS.