Characterizing the transduction behavior of ionic polymer-metal composite actuators and sensors via dimensional analysis

Author(s):  
Zakai Olsen ◽  
Kwang Jin Kim

Abstract Ionic polymer-metal composites (IPMCs) are functional smart materials that exhibit both electromechanical and mechanoelectrical transduction properties, and the physical phenomenon underlying the transduction mechanisms have been studied across the literature extensively. Here we use a new modeling framework to conduct the most comprehensive dimensional analysis of IPMC transduction phenomena, characterizing the IPMC actuator displacement, actuator blocking force, short-circuit sensing current, and open-circuit sensing voltage under static and dynamic loading. The information obtained in this analysis is used to construct nonlinear regression models for the transduction response as univariant and multivariant functions. Automatic differentiation techniques are leveraged to linearize the nonlinear regression models in the vicinity of a typical IPMC description and derive the sensitivity of the transduction response with respect to the driving independent variables. Further, the multiphysics model is validated using experimental data collected for the dynamic IPMC actuator and voltage sensor. With data collected from physical samples of IPMC materials in-lab, the regression models developed under the new computational framework are verified.

2013 ◽  
Vol 10 (78) ◽  
pp. 20120666 ◽  
Author(s):  
Sina Sareh ◽  
Jonathan Rossiter ◽  
Andrew Conn ◽  
Knut Drescher ◽  
Raymond E. Goldstein

Cilia are used effectively in a wide variety of biological systems from fluid transport to thrust generation. Here, we present the design and implementation of artificial cilia, based on a biomimetic planar actuator using soft-smart materials. This actuator is modelled on the cilia movement of the alga Volvox , and represents the cilium as a piecewise constant-curvature robotic actuator that enables the subsequent direct translation of natural articulation into a multi-segment ionic polymer metal composite actuator. It is demonstrated how the combination of optimal segmentation pattern and biologically derived per-segment driving signals reproduce natural ciliary motion. The amenability of the artificial cilia to scaling is also demonstrated through the comparison of the Reynolds number achieved with that of natural cilia.


Author(s):  
Yi-chu Chang ◽  
Won-jong Kim

Smart materials have been used in various applications. In this paper, a walking robot with six two-degree-of-freedom (2-DOF) legs made of ionic polymer metal composite (IPMC) is designed and implemented. Each leg can work as both a supporter and a driver, closely mimicking a real insect. To support and drive the robot, thicker (around 1 mm in thickness) IPMC strips were fabricated and used, and a 0.2-rad/s square wave is given as an input signal. The IPMC strips exhibit better performance in response to the square wave (8 mm) than sawtooth (4 mm) and sinusoidal (6 mm) waves in deflection. By applying this input signal in sequence, all the IPMC strips bend and walk in the form of six legs. In addition, thin magnet wires were used to supply power to each strip to prevent from confining the motion of our robot. Six lower legs are divided into two groups that work in the opposite directions to move the robot forward by turns. Upper legs are also divided into two groups to lift up their lower legs from making the robot to move back to the same place. The sizes of the IPMC strips and our robot (102 mm × 80 mm × 43 mm) were decided to exhibit better performance (0.5 mm/s) according to our tests.


2020 ◽  
Vol 31 (17) ◽  
pp. 1973-1985
Author(s):  
Hojat Zamyad ◽  
Nadia Naghavi ◽  
Reza Godaz ◽  
Reza Monsefi

The high application potential of ionic polymer–metal composites has made the behavior identification of this group of smart materials an attractive area. So far, several models have been proposed to predict the bending of an ionic polymer–metal composite actuator, but these models have some weaknesses, the most important of them are the use of output data (in autoregressive models), high complexity to achieve a proper precision (in non-autoregressive models), and lack of compatibility with the behavioral nature of the material. In this article, we present a hybrid model of parallel non-autoregressive recurrent networks with internal memory cells to overcome existing weaknesses. The validation results on experimental data show that the proposed model has acceptable accuracy and flexibility. Moreover, simplicity and compatibility with the behavioral nature of the material promote using the proposed model in practical applications.


Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 803 ◽  
Author(s):  
Yang Zhao ◽  
Jiazheng Sheng ◽  
Di Xu ◽  
Minzhong Gao ◽  
Qinglong Meng ◽  
...  

An ionic polymer–metal composite (IPMC) is a kind of soft material. The applications of IPMC in actuators, environmental sensing, and energy harvesting are currently increasing rapidly. In this study, an ordered Nafion nanofibre mat prepared by electrospinning was used to investigate the characteristics of the mechanoelectrical transduction of IPMC. The morphologies of the Nafion nanofibre mat were characterized. The proton conductivity, ion exchange capacities, and water uptake potential of the Nafion nanofibre mat were compared to traditional IPMC, respectively. A novel mechanism of Nafion nanofibre IPMC was designed and the open circuit voltage and short circuit current were measured. The maximum voltage value reached 100 mv. The output power was 3.63 nw and the power density was up to 42.4 μW/Kg under the load resistance. The Nafion nanofibre mat demonstrates excellent mechanoelectrcical transduction behavior compared to traditional IPMC and could be used for the development of self-powered devices in the future.


Author(s):  
G. Karthigan ◽  
Sujoy Mukherjee ◽  
Ranjan Ganguli

Ionic polymer metal composites (IPMC) are a new class of smart materials that have attractive characteristics such as muscle like softness, low voltage and power consumption, and good performance in aqueous environments. Thus, IPMC’s provide promising application for biomimetic fish like propulsion systems. In this paper, we design and analyze IPMC underwater propulsor inspired from swimming of Labriform fishes. Different fish species in nature are source of inspiration for different biomimetic flapping IPMC fin design. Here, three fish species with high performance flapping pectoral fin locomotion is chosen and performance analysis of each fin design is done to discover the better configurations for engineering applications. In order to describe the behavior of an active IPMC fin actuator in water, a complex hydrodynamic function is used and structural model of the IPMC fin is obtained by modifying the classical dynamic equation for a slender beam. A quasi-steady blade element model that accounts for unsteady phenomena such as added mass effects, dynamic stall, and the cumulative Wagner effect is used to estimate the hydrodynamic performance of the flapping rectangular shape fin. Dynamic characteristics of IPMC actuated flapping fins having the same size as the actual fins of three different fish species, Gomphosus varius, Scarus frenatus and Sthethojulis trilineata, are analyzed with numerical simulations. Finally, a comparative study is performed to analyze the performance of three different biomimetic IPMC flapping pectoral fins.


Author(s):  
Piqi Hou ◽  
Zhihang Ye ◽  
Zheng Chen

With advances in actuation and sensing, smart materials has drawn a growing attention from researchers in under water robotic fish. In this paper, a compact, noiseless, and untethered biomimetic robotic fish propelled by Ionic Polymer-Metal Composite (IPMC) actuators is developed. The robot fish employs two pectoral fins to generate steering and one caudal fin to generate main propulsion. A passive plastic fin is attached to the IPMC beam to enhance propulsion. With multiple IPMC fins, the fish is capable of 2D maneuvering. One small size programmable circuit board is designed for the 2D controllable fish. The Experimental results have shown that the forward-swimming speed can reach up to 1cm/sec and the both left-turning and right turning speed can reach up to 2 rad/sec.


2018 ◽  
Vol 29 (14) ◽  
pp. 2863-2873 ◽  
Author(s):  
Jakub Bernat ◽  
Jakub Kolota

Ionic polymer–metal composites are classified as a smart materials group, whose properties can be designed depending on the needs that arise. Ionic polymer–metal composites belong to the class of wet electroactive polymers. They are promising candidates actuator for various potential applications mainly due to their flexible, low voltage requirements, compact design, and lack of moving parts. However, being a widely used material in industry, ionic polymer–metal composite requires complex control methods due to its strongly nonlinear nature. An important prerequisite for an intelligent controller is the ability to adapt rapidly to any unknown operating environment. This article presents a novel approach to tuning multiple models of an online identifier by integral mapping. Through the extension of the estimation law of additional mapping between parameters and measurable signals, we significantly improve transient responses without increasing feedback gain. The authors measured the moisture content of ionic polymer–metal composite and consider in the experiment relationship between drying and varying of curvature output. The effectiveness of the proposed multiple models adaptive control strategy was verified in various experiments. The results of the study illustrated in the experiments show that adding new mapping improves not only the transients of controlled plant, but also increases the performance indexes of adaptive system.


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