Article
Engineering, Mechanical
Aman Khurana, Ajay Kumar, Atul Kumar Sharma, M. M. Joglekar
Summary: This paper theoretically analyzes the effect of internal properties of polymer chains on the performance of Dielectric Elastomer actuators in dynamic modes of actuation. The results show that strong entanglements and crosslinks in polymer chains result in lower deformation levels in DC dynamic modes of actuation. Moreover, the study assesses the periodicity and stability of nonlinear oscillations exhibited by viscoelastic DE actuators.
NONLINEAR DYNAMICS
(2021)
Article
Materials Science, Multidisciplinary
Gabriele Frediani, Hugh Boys, Michele Ghilardi, Stefan Poslad, James J. C. Busfield, Federico Carpi
Summary: This article reports progress on the development of a non-vibratory display of softness made of electroactive polymers, consisting of a hydrostatically coupled dielectric elastomer actuator shaped as a bubble interfaced to the fingertip, weighing 6 g. Prototypes can generate displacements up to 3.5 mm and forces up to 1 N. By combining this technology with a compact hand tracking sensor, a simple and cost-effective virtual-reality system is demonstrated. A psychophysical study involving 15 volunteers in poke and pinch tactile tasks shows that users can distinguish between different stimuli rendered by the display accurately, with accuracy correlated to the perceptual difficulty of the tactile comparative task.
ADVANCED MATERIALS TECHNOLOGIES
(2021)
Article
Engineering, Mechanical
Heng Feng, Shan Gao, Liying Jiang
Summary: This study develops a finite element framework combining nonlinear field theory with a micro-macro constitutive model incorporating nonlinear material viscosity to investigate electromechanical responses and instability of DE actuators. A highly customized user-element subroutine (UEL) in Abaqus is used for FE implementation. The effects of nonlinear material viscosity on various instability modes of DE actuators are numerically investigated and validated against experimental data and analytical studies.
EXTREME MECHANICS LETTERS
(2021)
Article
Chemistry, Physical
Bao Qin, Zheng Zhong, Tong-Yi Zhang
Summary: This paper aims to develop a thermo-electro-viscoelastic model for dielectric elastomers (DEs) to simulate their highly nonlinear stress-strain relations under various thermo-electro-mechanical loading conditions. A thermodynamically consistent continuum theoretical framework is developed to describe the thermo-electro-viscoelastic behaviors of DEs. The model is verified with experimental data and reveals the softening phenomena and instant pre-stretch induced by temperature and the electric field. This work is important for analyzing the failure of DEs in different thermo-electro-mechanical conditions.
Review
Energy & Fuels
Muhammad Khan, Tiehu Li, Asif Hayat, Amir Zada, Tariq Ali, Ikram Uddin, Ashiq Hayat, Majid Khan, Azeem Ullah, Amjad Hussain, Tingkai Zhao
Summary: In the past 20 years, electronic equipment has rapidly developed towards light, miniaturization, flexibility, and integration to meet the needs of intelligent communication and mobile medical treatment. Electroactive polymers (EAPs) are recommended for muscle-like actuation, with dielectric elastomers (DEs) capable of converting electrical energy into mechanical energy. Research focuses on material characteristics, electromechanical principles, and future applications of DEAs.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Mechanics
Angelo Carini, Francesco Genna, Francesca Levi
Summary: This paper derives new extremum principles in linear viscoelasticity from the general stationarity ones proposed in Carini and Mattei (2015), and obtains the analytical bounds of the homogenized viscous kernels of linear viscoelastic composites in the time domain. It also introduces the concept of Representative Volume Elements (RVEs) and obtains strict lower bounds of the homogenized viscous kernels.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2023)
Article
Materials Science, Characterization & Testing
Hong Wang, Liang Yang
Summary: In this study, the dielectric properties of electronic electroactive polymers (EEAP) were experimentally tested, and various factors such as frequency, voltage, electrode type, and specimen thickness were analyzed for their effects on the dielectric relaxation properties. Different models were used to accurately model the dielectric constants. The results showed that the dielectric constant of the polymer is strongly influenced by frequency, especially in the low frequency range. The use of G-C electrodes improved the electrical parameters of the polymer. The paper provides valuable reference for understanding the dielectric properties of polymers and their application in flexible robots.
Review
Chemistry, Multidisciplinary
Aleksey V. Maksimkin, Tarek Dayyoub, Dmitry V. Telyshev, Alexander Yu. Gerasimenko
Summary: Polymer actuators, with their unique properties such as light weight, easy processing, biodegradability, fast response, and good mechanical properties, are attracting more interest in biomedicine. Among them, electroactive polymers (EAPs) are considered the most attractive actuator type for prosthetics and soft robotics applications. However, robust control, modeling non-linear behavior, and scalable fabrication are the critical challenges for applying the soft robotic systems in real conditions.
Article
Engineering, Multidisciplinary
Rogelio Ortigosa, Jesus Martinez-Frutos, Antonio J. Gil
Summary: This paper presents a novel engineering strategy for the design of Dielectric Elastomer (DE) based actuators, capable of attaining complex electrically induced shape morphing configurations. The strategy involves the use of a multilayered DE prototype with different materials and the development of a computational approach for designing new prototypes with predefined configurations. The proposed methodology shows promise in efficiently determining optimal designs for complex electrically induced configurations.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Chemistry, Multidisciplinary
Gaoyu Liu, Yakui Deng, Bin Ni, Giao T. M. Nguyen, Cedric Vancaeyzeele, Annie Brulet, Frederic Vidal, Cedric Plesse, Min-Hui Li
Summary: A new type of electroactive liquid crystal elastomer (eLCE) with dual functionality, capable of bending or contracting deformation under low-voltage stimulation, is reported. This technology shows potential for the development of smart materials in the field of soft robotics, electronic devices, and sensors.
Article
Chemistry, Multidisciplinary
Yi Li, Bo Sun, Xuxin Feng, Mingfei Guo, Yanbiao Li, Minoru Hashimoto
Summary: CPVC gel is a promising material for soft actuators with enhanced mechanical and chemical properties. Experimental results show that CPVC gel actuators have higher strain and stress, demonstrating better performance under low applied loads.
Article
Chemistry, Multidisciplinary
Hayden E. Fowler, Philipp Rothemund, Christoph Keplinger, Timothy J. White
Summary: The integration of soft, stimuli-responsive materials in robotic systems allows for delicate object manipulation. Electrical control of mechanical response in liquid crystal elastomers (LCEs) results in rapid deformation with little hysteresis. The directional expansion and shape transformation capabilities of LCE actuators demonstrate promising applications in robotics.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Physical
Fabian L. L. Visschers, Dirk J. Broer, Danqing Liu
Summary: This study introduces a method to create dynamic pre-programmed surface textures by applying an alternating electric field on coatings with a silicon oxide reinforced viscoelastic siloxane network. The finite element method is developed to predict complex deformation shapes, and time-resolved experimental surface analysis is used to validate the predictions.
Review
Materials Science, Multidisciplinary
Jiwei Li, Yujie Feng, Weichao Chen, Shaohua Zhang, Jianwei Ma, Shaojuan Chen, Shangpeng Liu, Chengbo Cao, Yuankai Zhang
Summary: This review focuses on the structural design and antibacterial mechanisms of electroactive materials, including electrochemical materials, conductive materials, piezoelectric materials, and micro-batteries/galvanic couples. It also describes the biomedical applications of electroactive antibacterial materials in various areas such as bone tissue engineering, wound healing, medical catheters, oral healthcare, and wearable devices. The future challenges and perspectives associated with electroactive antibacterial materials are discussed. In summary, electroactive materials offer a promising platform for fighting bacterial infections and play a crucial role in the field of biomedicine.
PROGRESS IN MATERIALS SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Seonghyeon Jeong, Anne Ladegaard Skov, Anders Egede Daugaard
Summary: Actuators and generators play a crucial role in the green transition towards sustainable solutions. Dielectric transducers are considered as a promising solution, but their traditional production method leads to material loss and inhibits recycling. In this study, a cleaning method using surfactants and sonication is proposed to remove electrodes from the dielectric material, enabling reprocessing and recycling. Comparing with directly recycled materials, the cleaned material shows better performance and can be recycled for at least five cycles.
Article
Materials Science, Characterization & Testing
Behzad Ahmed Zai, M. A. Khan, M. K. Park, Majid Shahzad, M. A. Shahzad, Salman Nisar, S. Z. Khan, Kamran Khan, Aqueel Shah
JOURNAL OF TESTING AND EVALUATION
(2019)
Article
Engineering, Mechanical
Umer Zahid, Sohaib Z. Khan, Muhammad A. Khan, Hassan J. Bukhari, Salman Nisar, Kamran A. Khan
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART E-JOURNAL OF PROCESS MECHANICAL ENGINEERING
(2019)
Article
Materials Science, Composites
M. A. Ali, R. Umer, K. A. Khan, W. J. Cantwell
COMPOSITES SCIENCE AND TECHNOLOGY
(2019)
Article
Instruments & Instrumentation
Behzad Ahmed Zai, Muhammad A. Khan, Asif Mansoor, Sohaib Z. Khan, Kamran A. Khan
Article
Materials Science, Composites
Kamran A. Khan, Falah Al Hajeri, Muhammad A. Khan
JOURNAL OF COMPOSITE MATERIALS
(2019)
Article
Materials Science, Characterization & Testing
Behzad Ahmed Zai, Muhammad A. Khan, Sohaib Z. Khan, Muhammad Asif, Kamran A. Khan, Ahmad N. Saquib, Asif Mansoor, Majid Shahzad, Ahmed Mujtaba
JOURNAL OF TESTING AND EVALUATION
(2020)
Article
Materials Science, Multidisciplinary
Kamran A. Khan, Muhammad Ali Khan
MATERIALS RESEARCH BULLETIN
(2019)
Review
Engineering, Mechanical
Behzad Ahmed Zai, M. A. Khan, Kamran A. Khan, Asif Mansoor, Aqueel Shah, Majid Shahzad
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2019)
Article
Polymer Science
Kakur Naresh, Kamran A. Khan, Rehan Umer
Summary: This study investigated the effects of different graphene oxide concentrations on the mechanical and thermal properties of epoxy, proposing analytical models to predict Young's modulus and thermal conductivity. The 0.2 wt% nanocomposite samples showed relatively high storage modulus, heat-resistance index, and thermal conductivity compared to pure epoxy and lower concentration GO nanocomposites, indicating higher thermal stability.
Article
Polymer Science
Ahmed Abusabir, Muhammad A. Khan, Muhammad Asif, Kamran A. Khan
Summary: This study investigates the effect of architected structural member geometry and base material on the viscoelastic response of 3D printed lattice structure. The results show that both material and topology influence the mechanical properties and time-dependent behavior of the lattice structure. Plate-based lattices are the best choice for creep resistance, while shell-based lattices are ideal for damping applications under quasi-static loading conditions.
Article
Polymer Science
Sultan Al Hassanieh, Ahmed Alhantoobi, Kamran A. Khan, Muhammad A. Khan
Summary: Three novel re-entrant plate lattice structures were designed and fabricated using additive manufacturing technology, and the elastic anisotropy of the lattice structures was studied. The FPV and FPMA showed anisotropic behavior while the FPT showed cubic symmetry. In terms of compressive response, the FPMA had the highest Young's modulus, with a mixed bending-stretching behavior, while the FPT exhibited a stretching-dominated behavior.
Article
Chemistry, Physical
Shahryar Manzoor, Israr Ud Din, Khaled Giasin, Ugur Koklu, Kamran A. Khan, Stephane Panier
Summary: Considering the challenges in machining composites, this study numerically evaluated the effects of cutting parameters on thrust force and torque during drilling of glass-fiber-reinforced polymers. A developed model accurately predicted the thrust force and torque profiles, providing useful guidelines for drilling operations to minimize drilling-induced damage. The study also investigated the effect of coefficient of friction and found that higher friction reduced the thrust force.
Article
Polymer Science
Bilal Ahmad, Fahad Almaskari, Jamal Sheikh-Ahmad, Suleyman Deveci, Kamran Khan
Summary: In this study, a thermomechanical model of friction stir welding (FSW) of high-density polyethylene (HDPE) was developed using a Coupled Eulerian-Lagrangian (CEL) approach. Experimental data on strain rate and temperature-dependent stress-strain behavior were used to develop a material model for HDPE. Numerical simulations were performed using two sets of FSW process parameters, and the results were compared to experimental data to validate the model. Tracer particles were used to visualize material movement during and after the FSW process. The numerical models showed good agreement with the experimental results, and the effects of different process parameters on temperature distribution, material flow, and weld defects were analyzed.
Article
Polymer Science
Ahmed I. Alhatti, Jamal Sheikh-Ahmad, Fahad Almaskari, Kamran A. Khan, Suleyman Deveci, Abdelrahman I. Hosny
Summary: This study investigates the effectiveness of a tapered fluted pin tool design in the friction stir lap welding (FSLW) technique for creating hybrid joints between AA5052 aluminium alloy and polypropylene (PP). The optimal welding parameters were found to be a rotational speed of 1400 RPM and a traverse speed of 20 mm/min, resulting in a joint tensile strength of 3.8 MPa. The microstructural evaluations revealed a unique composite of aluminium chips intermeshed with PP, strengthened further by aluminium hooks. Mechanical interlocking plays a predominant role over chemical bonding in achieving this joint strength.
Proceedings Paper
Engineering, Multidisciplinary
Sohaib Z. Khan, Umair Ahmed, Sallar Qazi, Salman Nisar, Muhammad A. Khan, Kamran A. Khan, Farrauk Rasheed, Muhammad Farhan
PROCEEDINGS OF 2019 16TH INTERNATIONAL BHURBAN CONFERENCE ON APPLIED SCIENCES AND TECHNOLOGY (IBCAST)
(2019)