PLENARY SPEAKER
Our plenary speakers are leading researchers from around the world, sharing their expertise and the latest developments in the field.
Dr Mahdi Bodaghi
Affiliation: Department of Engineering, Nottingham Trent University
4D Printing and Programming of Magneto-Electro-Responsive Polymers
Dr Mahdi Bodaghi, Associate Professor
Department of Engineering, Nottingham Trent University
Four-dimensional (4D) printing enables polymer structures to be programmed during manufacturing and reconfigured through stimuli. This lecture presents an integrated framework for 4D printing and programming magneto-electro-responsive polylactic acid (PLA) systems. First, magnetic-field-assisted fused deposition modelling is used to print iron-particle-filled PLA under sub-tesla magnetic fields. Particle magnetisation induces macroscopic strains during deposition, enabling geometry and mechanical strain to be tailored without moulds. A multi-physics constitutive model, incorporating real-time temperature of deposited layers, accurately captures the evolution of field-induced deformation. Second, simultaneous printing and magnetisation are employed to enhance the magneto-mechanical performance of iron-filled PLA. Controlling magnet position, field direction, and deposition angle increases specific magnetisation by 63.46% and tensile strength by 21.4%, demonstrating that functional anisotropy can be encoded through the manufacturing process. Finally, magnetic PLA is integrated with carbon-black-filled conductive PLA to create magneto-electroactive shape-memory structures. Joule heating enables electrical programming and shape recovery, while magnetic fields provide remote control and switching between multiple stable configurations. The printed structures repeatedly transform from 1- and 2-dimensional forms into 2- and 3-dimensional geometries without continuous stimulation. These advances collectively establish a scalable route towards programmable actuators, deployable structures, soft robotic systems, and adaptive devices with reduced material and energy consumption.
Short bio: Dr Mahdi Bodaghi is an Associate Professor of Smart Materials and Manufacturing in the Department of Engineering at Nottingham Trent University and Founding Director of the 4D Materials & Printing Lab. His research lies at the intersection of smart materials, metamaterials, bio-composites, and advanced 3D/4D printing. He develops programmable materials, architected structures, and sustainable composite systems for applications spanning healthcare, protective equipment, soft robotics, and engineering. He has published more than 370 peer-reviewed papers, and his work has received over 18,500 citations. Dr Bodaghi is a Chartered Engineer and Fellow of the Higher Education Academy. He is Founding Editor-in-Chief of the 4D Printing Journal, co-founder of the 4D Printing Society, and co-editor of the Elsevier book series Smart Materials in Additive Manufacturing. He works closely with academic, clinical, and industrial partners to translate fundamental research into practical technologies and has delivered invited and keynote lectures at major international conferences.
Dr. Maria Daniela Contreras-Mateus
Affiliation: TUD Dresden University of Technology - Dresden, Germany
Magnetically responsive heavy crude oils: from field-induced microstructures to magnetorheology
Dr. Maria Daniela Contreras-Mateus
Dr., P. Magnetofluiddynamik, Mess-/Autotech.
TUD Dresden University of Technology
Dresden, Germany
Global energy policies are currently undergoing a profound transformation toward a secure, sustainable, and affordable system, framed by international commitments aimed at reaching net-zero emissions by 2050. Although investments in renewable energy technologies are projected to increase substantially over the coming decades, fossil fuels will remain critical to ensuring short- and medium-term energy security, a reliance particularly pronounced in essential sectors, such as aviation, shipping, and petrochemicals, whose operations rely directly on petroleum-derived fuels and feedstocks.¹ Accordingly, maximizing the efficiency of unconventional resources, which represent nearly 70% of worldwide petroleum reserves, has become an imperative strategy for the oil industry to fulfill international climate targets while preventing supply shortfalls and severe price volatility. Within this framework, nanotechnology has emerged as a key alternative to optimize oil recovery and transportation processes through interfacial and rheological modulation. Among functional nanomaterials, metal oxide nanoparticles have gained significant interest as versatile candidates, due to their high surface area, selective affinity for asphaltenes, and superparamagnetic properties.²
This presentation will provide a theoretical and experimental perspective on the integration of ferrofluids into heavy crude oil matrices, highlighting the feasibility of inducing magnetorheological properties through the optimization of physicochemical interactions between functional superparamagnetic nanoparticles and native crude oil components, focusing predominantly on asphaltenes. As a starting point, the discussion will outline the fundamental role of this fraction, whose pronounced affinity for nanoparticle surfaces promotes selective adsorption and the spontaneous formation of hybrid supramolecular aggregates³ Building upon these insights, experimental evidence will be presented to show how external magnetic fields align these hybrid structures, leading to field-induced microstructural reorganization and controllable rheological behavior of heavy crude oils.⁴ These principles will then be extended to multiphase systems through the formulation of magnetically responsive crude oil emulsions, in which the interfacial activity of asphaltenes is harnessed to induce enhanced magnetoviscous effects. Finally, the talk will conclude with an outlook encompassing the coupling between nanoparticle-asphaltene interactions, field-induced microstructures, and magnetorheology, to provide a scientific foundation for future field-based strategies in heavy crude oil transportation and flow assurance.
References
- IEA (2026) Global Energy Review 2026. https://www.iea.org/reports/global-energy-review-2026.
- Contreras-Mateus, M. D.; Chaves-Guerrero, A.; Sánchez, F. H.; Nassar, N. N. Physics of Fluids 2024, 36 (12), 121302.
- Contreras–Mateus, M. D.; Sánchez, F. H.; Cañas-Martínez, D. M.; Nassar, N. N.; Chaves–Guerrero, A. Fuel 2022, 318, 123684.
Professor Juan de Vicente
Affiliation: University of Granada, Spain
Programming Magnetic Soft Matter with Time-Dependent Fields: From Self-Assembly and Rheology to Living Hydrogels
Professor Juan de Vicente
University of Granada, Spain
Magnetorheological materials are classically viewed as suspensions in which magnetizable particles assemble into chain-like structures under steady magnetic fields, producing large and reversible changes in their rheological properties. Although this paradigm has been highly successful, it also restricts the accessible structural landscape and often results in kinetically trapped, defect-rich aggregates.
In this talk, I will show how time-dependent magnetic forcing can transform magnetic history into a design variable for magnetic soft matter. Toggled and biaxial fields combine magnetic aggregation with relaxation periods or orthogonal perturbations. This promotes particle reorganization, reduces structural defects, and provides control over aggregate compactness, anisotropy, connectivity and percolation. Because stress transmission strongly depends on microstructure, these protocols also offer new ways to reinforce field-induced networks and tune their viscoelastic response beyond what can be achieved by changing the field strength alone.
I will then discuss how triaxial time-dependent fields can be used to program the effective interactions between magnetic particles. Depending on the competition between magnetic and hydrodynamic timescales, particles may either follow the instantaneous field or respond to its time-averaged effect. This makes it possible to generate periodic layers, compact networks and other architectures that are not accessible under stationary magnetic fields. These field-programmed structures can also be immobilized during hydrogel gelation, producing magnetic hydrogels with persistent anisotropy, directional mechanical properties and spatial cues for living cells.
Finally, I will briefly show how time-dependent magnetic gradients can be combined with the nonlinear rheology of the suspending medium to generate directed particle transport through ratchet-like mechanisms. Together, these examples provide a general framework for expanding magnetorheology from materials that simply respond to an applied field towards magnetic soft materials whose microstructure, mechanics and transport can be programmed through the temporal characteristics of the field.
DSc. Nikita M. Kuznetsov
Affiliation: National Research Center “Kurchatov Institute”: Moscow, Russia
Nikita M. Kuznetsov
Nanobiomaterials and Structures Department, National Research Center "Kurchatov Institute", Russia
Microsensory Innovation and Engineering Center, MIREA - Russian Technological University, Russia
E-mail: kyz993@yandex.ru
ORCID: 0000-0002-1241-3115
Keywords: electrorheological fluids, smart materials, filler design, polymer fillers, porous microparticles
Abstract: Among the large number of stimuli-responsive materials, electrorheological fluids are of particular interest. Typically, they are dispersions of easily polarizable filler particles in dielectric liquid medium. Such dispersions are capable of rapid and reversible transition to a solid-like state under an electric field, due to fibrillary structures formation from filler particles [1]. The properties of electrorheological fluids are affected by a numerous factors. In addition to the concentration of the dispersed phase, the electric field strength, the temperature, and the viscosity of the base fluid, the nature of the filler and dispersion medium (typically silicon oil), as well as the additives, have a significant impact. Nevertheless, the filler remains the key component of electrorheological materials. Thus, the variety of suitable fillers offers possibility for improving the performance of fluids. In particular, the application of hollow particles and fillers with a core-shell structure allows for the control of electrorheological behavior over a wide range. A relatively novel area is the development of low-filled fluids with functional yield stress values for the high relative fluid efficiency at a reduced cost [2]. This advancement has been made possible by the particles with a high aspect ratio and by the design of highly porous polymer macronetworks (microparticles). Polymer fillers are of particular interest in this regard, since their properties can be adjusted both by modifying the neat polymer molecule during synthesis and by supramolecular organization with the formation of associates, particles, and frameworks. The role of filler structure can be examined using polymer particles of various chemical nature both natural and synthetic, including chitosan, cellulose, polyaniline, poly(3,4-ethylenedioxythiophene)polystyrene sulfonate, and their composites as well. The different nature of the fillers is primarily reflected in the electrical characteristics of fluids followed by a corresponding change in the electrorheological behavior. Such differences are clearly established by the dielectric permittivity, dielectric loss and polarization activation energy. The application of environmentally friendly components is relevant from the perspective of green chemistry and sustainable development. Therefore, expanding the concept of supramolecular filler design to the area of natural raw materials, such as clays, polysaccharides, natural oils, etc., is promising as an alternative to existing fluids. The report discusses some strategies for targeted modification of the functional fillers to improve the performance of electrorheological fluids and to develop materials with advanced properties.
References
[1] Kuznetsov N.M. et al. Electrorheological fluids: from historical retrospective to recent trends. Materials Today Chemistry. 2022, V. 26, P. 101066.
[2] Kuznetsov N.M., Chvalun S.N. Recent advances in electrorheological fluids. Colloid Journal. 2025, V. 87, № 6. P. 903-938.
Dr. Weihua Li
Affiliation: School of Engineering, University of Wollongong, Australia
A Magnetorheological Resettable Inerter-Based Energy Harvesting System
Weihua Li
School of Engineering, University of Wollongong, Australia
Abstract
This study proposes a novel Magnetorheological (MR) Resettable Inerter-Based Energy Harvesting System. The system integrates a resettable inerter with MR clutch and braking mechanisms. This design achieves controllable inertial coupling through intermittent engagement and reset actions. Unlike continuously variable systems, this architecture enables piecewise energy transfer. It temporarily stores kinetic energy within a rotating flywheel, then releases and harvests it during controlled reset events. Consequently, this approach provides adaptive modulation of effective inertance while regulating structural and drivetrain loads. In this work, both analytical and numerical models are developed to investigate switching strategies under both regular and irregular wave conditions. We evaluate its performance against conventional and variable-inertance approaches to quantify improvements in energy capture, dynamic response, and load mitigation. Additionally, a laboratory-scale prototype and experimental validation assess the practical feasibility of the concept. The proposed technology establishes a new application for resettable inerter systems in marine renewable energy. By combining adaptive inertial control and energy harvesting into a single architecture, the proposed device enhances both energy yield and operational resilience for future wave energy converters.
Dr. Yancheng Li
Affiliation: University of Technology Sydney, Sydney, Australia
The evolution of magnetorheological vehicle suspension: From luxury cars to mainstream mobility
Yancheng Li
Faculty of Engineering and Information Technology, University of Technology Sydney, Ultimo, NSW 2007, Australia
The past decade has witnessed remarkable advances in magnetorheological vehicle suspension, driven by the rapid transformation of the automotive industry in China and worldwide, particularly vehicle electrification, mass-market adoption, and the resulting substantial cost reductions. In China alone, more than ten electric and conventional vehicle models are reportedly scheduled to feature MR suspension as standard equipment, signalling its transition from a premium option to a mainstream chassis technology. This plenary talk traces the evolution of MR vehicle suspension from specialised applications in luxury cars to increasingly diverse platforms, including sport utility vehicles and racing cars. Drawing on developments across multiple vehicle programmes, it highlights the key scientific and engineering challenges involved in translating MR technology from material and device concepts into production-ready suspension systems. These include vehicle-grade MR fluids, application-specific damper design, performance modelling, control algorithm development, and vehicle-level system integration. The talk will further discuss the lessons learned from these developments and the future direction of scalable, intelligent, and application-adaptive MR suspension.
Prof. Masami Nakano
Affiliation: Tohoku University, Sendai, Japan
Dry MRF based Clutch combined with Brake for Cooperative Regenerative Braking System of HEV/EV
Prof. Masami Nakano
Tohoku University, Sendai, Japan
Representative Director & CEO, SmartTECH Lab. Inc.
Abstract: MR(Magneto-rheological) fluids are the suspensions with micron-sized ferromagnetic particles dispersed into carrier oil, and are one of smart fluids which can be changed their rheological properties in reversible manner by applying magnetic field. So, there are many possible applications to automobiles, industrial machines, control systems, and robotics, etc. as well as some mechanical elements such as brakes, clutches, valves, and dampers. In these applications, the zero-field initial viscosity of the MR fluids should be regulated as low as possible to minimize the energy loss and to maximize the dynamic range of the MR effect, and the operating temperature should be lower, higher, and wider. However, since the carrier medium is a liquid, the limits of the viscosity reduction and the lower and higher operating temperature exist, because the increase of the particle volume fraction increases the zero-field viscosity and the operating temperature mainly depends on the freezing and boiling points of the carrier oil.
To overcome the above limits and restrictions for the conventional MR fluids, novel "dry MR fluids (fluidic magnetic powder) without liquid medium" have been proposed and fabricated for the first time, featuring extremely low zero-field viscosity, higher dynamic range and higher operating temperature [1]. To improve the fluidity of the dry MR fluid, the dispersed micron-sized carbonyl iron particles were coated with nano-sized silica (SiO2) particles [1]. The optimized dry MR fluid has been applied to the automotive brake of multi-disk type for a super-compact electric vehicle, which was specifically designed for the dry MR fluid [2].
In this study, a new dry MR fluid of micron-sized CI particles coated with nano-sized titania (TiO2) particles without liquid medium has been fabricated to further improve the fluidity of dry MR fluid, resulting in very high loose bulk density and higher dynamic range of the dry MR fluid. A multi-disk type clutch combined with brake using this new dry MR fluid has been developed to apply for a cooperative regenerative braking system of a hybrid electric vehicle (HEV) and an electric vehicle (EV). The design of the developed dry MR fluid clutch combined with brake is described. And the steady and transient torque characteristics of the clutch and brake parts have been investigated independently as a function of the applied current. The driving shaft and follower shaft of the clutch combined with brake should be connected to the shaft of driving wheels and a driving/regenerative motor for a cooperative generative braking system of EHV / EV, respectively. The motor works to generate driving torque as a motor in the stage of driving or regenerative braking torque as a generator (regenerative brake) in the stage of braking. And, the combined dry MRF brake works to generate additive braking torque in addition to the regenerative braking torque in the stage of braking.
[1] M. Nakano, H. Abe, T. Tian, A. Totsuka, C. Sato, Magneto-Rheological Effects and Fluidity Improvement of Novel Dry MR Fluids, Proc. of 10th JFPS Int. Symp. on Fluid Power, Paper No.1B11, (2017), pp.1-5.
[2] M. Nakano, O. Taguchi, F. Shibata, S. Sun, J. Yang, H. Abe, Development of Dry MR Fluid Brake for Super-compact Electric Vehicle, Proc. of 16th Int. Conf. on Flow Dynamics (ICFD2019), (2019), pp.392-393.
Prof. Stefan Odenbach
Affiliation: TUD Dresden University of Technology - Dresden, Germany
Prof. Stefan Odenbach
Pr. Jean-Sébastien Plante
Affiliation: Université de Sherbrooke, Sherbrooke, Québec, Canada
From Automotive Dampers to Robotic Actuators: Lessons Learned and Future Directions for Rotary Magnetorheological Actuation
Pr. Jean-Sébastien Plante
Université de Sherbrooke, Sherbrooke, Québec, Canada
Abstract: More than two decades ago, magnetorheological (MR) technology achieved its first large-scale commercial success through linear dampers used in General Motors' semi-active suspension systems. While these applications demonstrated the robustness and practicality of controlled MR fluids, rotary MR actuators have followed a much slower path toward commercialization. Today, however, advances in actuator design, control, and manufacturing are enabling rotary MR technology to gain traction in robotics, aerospace, automotive systems, prosthetics, and wearable assistive devices.
This talk will review the evolution of rotary MR actuators through representative industrial and research applications, including robotic manipulators, aerospace haptic inceptors, active suspension systems, prosthetics, and exoskeletons. For each application, system requirements, performance metrics, and comparisons with competing actuation technologies will be examined. Particular attention will be paid to a common design principle emerging from successful implementations: the use of the highest practical mechanical gearing ratio while maintaining the desired system dynamics. This principle enables designers to preserve the intrinsic advantages of MR actuation, including controllable impedance and inherent safety, while achieving high torque density at low cost.
The presentation will then discuss recent advances in the field and identify the primary factors currently limiting the broader adoption of rotary MR technology. Challenges related to fluid durability, actuator downscaling, and centrifugal particle sedimentation will be examined, highlighting the gap between laboratory demonstrations and long-term industrial deployment.
Finally, future research directions will be proposed to address these challenges and accelerate technology transfer. By connecting practical engineering needs with fundamental research opportunities, this talk aims to provide a roadmap for enabling rotary MR actuators to achieve the same level of industrial success and impact as their linear counterparts.
SHORT BIO
Pr. Jean-Sébastien Plante is a Professor of Mechanical Engineering at the Université de Sherbrooke, entrepreneur, and inventor. Since earning his Ph.D. in Robotics from MIT in 2006, he has authored more than 75 scientific journal publications and contributed to over 40 patents worldwide.
He directs the Studio de Création, one of Canada's largest university prototyping centers, supporting more than 3,000 members. He is also a co-founder of Createk, a research team dedicated to bridging academic research and industrial impact.
Professor Plante's work spans advanced actuation, robotics, and energy systems. His innovations, including geared magnetorheological actuators and inside-out ceramic gas turbines, have been successfully commercialized through Exonetik, a technology company he co-founded, where he serves as Chief Technology Officer.
Prof. Andrea Spaggiari, PhD
Affiliation: University of Modena and Reggio Emilia, Italy
Magnetic shape-programmable magnetorheological metamaterial
Prof. Andrea Spaggiari, PhD
Associate Professor of Machine Design
DISMI - Dipartimento di Scienze e Metodi dell’Ingegneria
University of Modena and Reggio Emilia, Italy
Abstract
Magnetorheological metamaterials combine the geometry-dependent properties of mechanical metamaterials with the controllable, field-responsive behavior of magnetically active particles embedded in their constituent material. This coupling enables rapid and reversible changes in stiffness, damping, deformation, and wave-propagation characteristics. These capabilities make magnetorheological metamaterials promising for adaptive vibration and seismic isolation, tunable acoustic devices, impact protection, soft robotics, haptic systems, prosthetics, and morphing structures. This talk explores how the interaction between the mechanical architecture and magnetic response of a W-shaped elastomer filled with magnetic nanoparticles influences the system’s behavior under mechanical loading and magnetic fields, as well as its ability to undergo large, programmable deformations. Numerical simulations and experimental tests show good agreement, demonstrating that the combination of magnetorheological materials and architected structures offers a feasible approach to developing controllable materials for soft-robotic grasping applications.
Keywords: Magnetorheological elastomers; mechanical metamaterials, shape programmability
SHORT BIO
Andrea Spaggiari has been an Associate Professor at the Department of Engineering Sciences and Methods since 2020. His research activities focus on actuators and devices based on Nitinol, bonded structural joints, fluidic systems and magnetorheological elastomers, and mechanical metamaterials. He has established numerous national and international research collaborations, both in academic research, with universities in Poland, Ireland, and Mexico, and in technology transfer initiatives. He is the coordinator of the Reggiane3D Project, aimed at the technical–historical reconstruction of OMI–Reggiane designs through 3D CAD modeling and the GIFTED project related to the additive manufacturing of endovascular devices in NiTinol. He authored more than 90 scientific papers and several book chapters.
Prof. Rongjia Tao
Affiliation: Department of Physics, Temple University, Philadelphia, PA, USA
Electrorheological Fluids and Magnetorheological Suspensions: Past Achievements, Present Challenges, and Future Opportunities
Prof. Rongjia Tao
Department of Physics, Temple University, Philadelphia, PA, USA
Since the first International Conference on Electrorheological (ER) Fluids and Magnetorheological (MR) Suspensions, the ER and MR fields have evolved from scientific curiosity into an active interdisciplinary research area encompassing physics, materials science, chemistry, mechanics, and engineering. Over the past four decades, remarkable progress has been made in understanding the fundamental mechanisms of field-induced rheological phenomena, developing advanced ER and MR materials, and exploring a wide range of scientific and engineering applications.
This lecture presents a historical retrospective on the evolution of ER and MR research and the role that the ERMR conference series has played in fostering international collaboration and scientific exchange. Major achievements and milestones will be reviewed, followed by a discussion of the current scientific and technological challenges.
Looking ahead, the lecture will examine emerging opportunities that are expanding the traditional boundaries of the field. Successful engineering applications, based on increasing viscosity and yield stress, lead to dampers, clutches, brakes, and vibration control. Meanwhile with different electric or magnetic field configurations, the ER and MR effect produces entirely different flow behaviors, including flow enhancement and turbulence suppressing, thereby opening opportunities in energy transportation and biomedicine.
The lecture concludes with perspectives on future research directions and the opportunities available to the next generation of scientists and engineers to further advance this unique and evolving field.
Prof. Eric R. Weeks
Affiliation: Emory University, Atlanta USA
Polydispersity enhances the performance of magnetorheological fluids
Prof. Eric R. Weeks
Emory University, Atlanta USA
An ideal magnetorheological (MR) fluid has a low viscosity in the absence of a magnetic field and a high yield stress when magnetized. Both properties depend directly on the composition, volume fraction, size, and size distribution (polydispersity) of the suspended particles. We show that a highly polydisperse particle size distribution improves both properties at once, because polydispersity raises the maximum volume fraction to which the particles can be packed. Recent work has established that the viscosity of a colloidal suspension is governed by the gap between its actual volume fraction and this maximum packing fraction; at equal volume fraction, a highly polydisperse sample is therefore less viscous than a nearly monodisperse one. The same principle applies when a magnetic field drives the particles into chains: within the chains, particles pack at local volume fractions approaching the maximum, so highly polydisperse samples form denser chains and exhibit a higher yield stress. We conclude by discussing how the shape of the size distribution can be tuned to optimize the packing of ideal hard spheres.
Norman M. Wereley, Ph.D.
Affiliation: University of Maryland, College Park, MD 20742 USA
Magnetorheological Energy Absorption for Occupant Protection in Aerospace and Automotive Vehicles
Norman M. Wereley, Ph.D.
Minta Martin Professor
Dept. of Aerospace Engineering , University of Maryland
College Park MD 20742 USA
wereley@umd.edu
Abstract: The goal of protecting occupants from potentially injurious vibration, repetitive shock, crash and blast loads, is becoming a critical issue as the cumulative impact of these load spectra on chronic health and acute injury are better understood. The objective of this talk is to discuss what properties are optimal for energy absorption (EA) applications such as impact or shock load mitigation. Two primary strategies will be discussed in this talk: passive vs. semi-active energy absorbers. The first focus is the use of crushable materials to absorb energy such as composite cellular materials. The second focus is the use of magnetorheological fluids (MRFs) or magnetorheological elastomers (MREs) in EA applications. The properties of the MRF can be optimized for a particular application. A number of key nondimensional parameters can be used to gain insight into how to define optimality for various applications including: Bingham number, Hedstrom number, Reynolds number, Mason number, dynamic range. Also, the trade-offs associated in designing an optimal MRF for a particular application are discussed. The advantages of passive versus semi-active EA strategies will be discussed.
Biosketch: Dr. Wereley‘s current research interests are focused on active and passive vibration and shock mitigation (especially occupant protection systems) using primarily magnetorheological materials, and soft actuators and soft robotic systems. Dr. Wereley has published over 280 journal articles, 20 book chapters, 275 conference articles, and 20 patents. Dr. Wereley is the Editor-in-Chief of SAMPE Journal and Editor of the ACTUATORS. He also serves as an associate editor of Smart Materials and Structures, MDPI Aerospace, among others. Dr. Wereley is the recipient of the ASME Adaptive Structures and Material Systems Prize (2012) and the SPIE Smart Structures and Materials Lifetime Achievement Award (2013). Dr. Wereley is a Fellow of AIAA, ASME, CSME, IOP, RAeS, SAMPE, SPIE, and VFS. He is also a Senior Member of IEEE. Dr. Wereley has a B.Eng. (1982) from McGill University and M.S. (1987) and Ph.D. (1990) from the Massachusetts Institute of Technology.
Prof. Jianbo Yin, Ph. D
Affiliation: Northwestern Polytechnical University, Xi’an, China
Electrorheological effect of poly(ionic liquid) ellipsoid suspensions
Prof. Jianbo Yin, Ph. D
Smart Materials Laboratory, Department of Applied Physics, School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an, Shaanxi, 710129, China
E-mail address: jbyin@nwpu.edu.cn
Abstract: Although particle shape has an important influence on the properties of suspensions, such as sedimentation, polarization, and electrorheology, the unveiling of shape influence on these properties remains incomplete because suitable electro-active particles having different shapes but the same volume and chemical structure are scarcely available. This limits the material design. Recently, we used a uniaxial thermomechanical stretching and squeezing identical monodisperse electro-active poly(ionic liquid) (PIL) microspheres to prepare uniform PIL ellipsoids having a continuous shape change from prolate to oblate spheroids. In this topic, we present the detailed experimental study concerning the particle shape influence on the sedimentation, polarization and electrorheology of suspensions. It showed that high shape anisotropy can significantly decrease particle settling velocity, while the spheroids with low shape anisotropy show slightly higher settling velocity than spherical counterparts. Both prolate and oblate PIL spheroids with high shape anisotropy exhibit high long-axis and overall interfacial polarization strengths, making their long axis more prone to electro-orientate and form long and thick particle chains. As a result, they show significant enhanced electrorheological effect compared to spherical counterparts. The difference between the long-axis and short-axis relaxation strengths of spheroids with low shape anisotropy becomes small and the overall interfacial polarization strength of suspensions decreases, leading these spheroids to electro-orientate randomly and form short and thin particle chains. As a result, their electrorheological effect decreases. The prolate PIL spheroids with axial ratio (q) of about 2.0 shows lower electrorheological effect compared to spherical counterparts because they have higher probability of contact between short axes. Although the oblate PIL spheroids with q of about 0.5 have similar short-axis length with prolate PIL spheroids with q of about 2.0, the former shows higher electrorheological effect compared to spherical counterparts because of contributions from two long axes. The results give a full clarification about the influence of shape on the sedimentation, interfacial polarization and electrorheology of particle suspensions, and highlight the respective advantage of rod-like and plate-like particles with suitable aspect ratio in improving electro-responsive and sedimentation properties.
Yin is a Professor at School of Physics Science and Technology, Northwestern Polytechnical University, China. He obtained B. S. at Northwestern Polytechnical University in 1998 and Ph. D from the same university in 2010. He serves as Editorial Board Member of Materials and Scientific Reports, and Reviewing Editor of Frontiers in Materials-Smart Materials. He has obatined the Ministry of Education's New Century China Excellent Talent Award and the China Society of Rheology Young Scientist Award. He is a Fellow of International Association of Advanced Materials. His research interests focuses on electrorheological fluids, poly(ionic liquid)s, and microspheres.
Prof. Miao Yu
Affiliation: Chongqing University, Chongqing China
Magnetorheological Elastomer-Based Quasi-Zero-Stiffness Isolation for Micro-Vibration Mitigation: Mechanisms, Bidirectional Tunability, and Adaptive Control
Prof. Miao Yu
Chongqing University, Chongqing China;
Abstract: Low-frequency micro-vibrations pose significant challenges to precision instruments and space optical systems. This talk presents a magnetorheological elastomer (MRE)-based quasi-zero-stiffness (QZS) isolator integrating tunable positive stiffness and a negative-stiffness mechanism for enhanced low-frequency vibration isolation. The talk addresses three key questions:
Stiffness matching and optimization: How can positive and negative stiffness be optimally matched to establish a stable QZS region while maintaining adequate load-bearing capacity?
Bidirectional stiffness tunability: How can the magnetic-field-dependent mechanical properties of MREs be exploited to regulate the stiffness balance and dynamic response of the isolator in both directions?
Adaptive vibration control: How can adaptive control strategies be developed and experimentally validated to maintain effective isolation under varying payloads and excitation amplitudes?
By addressing these questions, the talk explores the integration of structural design, stiffness optimization, bidirectional tunability, and adaptive control, highlighting the potential of MRE-based QZS isolators for micro-vibration mitigation in precision instruments and space optical systems.