Thermodynamic Modeling of Ionic Polymer-Metal Composite Beams

Author(s):  
Jayavel Arumugam ◽  
Arun Srinivasa

A thermodynamically consistent model to simulate the electromechanical response of ionic polymer-metal composite (IPMC) beams has been developed based on Euler-Bernoulli beam theory. Appropriate assumptions have been made and suitable forms for the Helmholtz free energy and the rate of dissipation have been chosen. The governing equations, describing the actuation and sensing behavior of IPMC strips in air, have been formulated using a set of kinematic assumptions, the power theorem, and the maximum rate of dissipation hypothesis, neglecting inertial effects. The model has been extended to solve for large deformations in IPMC cantilevers with certain loading conditions. The model has been shown to simulate the electromechanical responses of both Nafion and Flemion based IPMC strips. This includes the initial overshoot followed by a gradual back-relaxation observed in the tip deflection measurements of Nafion based IPMC strips under the application of a step voltage. It has been shown that a coupled convective heating term in the rate of dissipation function is crucial for simulating this overshoot and the back relaxation.

2012 ◽  
Vol 23 (10) ◽  
pp. 1069-1082 ◽  
Author(s):  
Ganesan Karthigan ◽  
Sujoy Mukherjee ◽  
Ranjan Ganguli

Ionic polymer–metal composites are soft artificial muscle-like bending actuators, which can work efficiently in wet environments such as water. Therefore, there is significant motivation for research on the development and design analysis of ionic polymer–metal composite based biomimetic underwater propulsion systems. Among aquatic animals, fishes are efficient swimmers with advantages such as high maneuverability, high cruising speed, noiseless propulsion, and efficient stabilization. Fish swimming mechanisms provide biomimetic inspiration for underwater propulsor design. Fish locomotion can be broadly classified into body and/or caudal fin propulsion and median and/or paired pectoral fin propulsion. In this article, the paired pectoral fin–based oscillatory propulsion using ionic polymer–metal composite for aquatic propulsor applications is studied. Beam theory and the concept of hydrodynamic function are used to describe the interaction between the beam and water. Furthermore, 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 obtain hydrodynamic performance of the ionic polymer–metal composite propulsor. Dynamic characteristics of ionic polymer–metal composite fin are analyzed using numerical simulations. It is shown that the use of optimization methods can lead to significant improvement in performance of the ionic polymer–metal composite fin.


2011 ◽  
Vol 17 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Mohammad Luqman ◽  
Jang-Woo Lee ◽  
Kwang-Kil Moon ◽  
Young-Tai Yoo

Author(s):  
Muhammad Farid ◽  
Zhao Gang ◽  
Tran Linh Khuong ◽  
Zhuang Zhi Sun ◽  
Naveed Ur Rehman ◽  
...  

Biomimetic is the field of engineering in which biological creatures and their functions are investigated and are used as the basis for the design and manufacturing of machines. Ionic Polymer Metal Composite (IPMC) is a smart material which has demonstrated a meaningful bending and tip force after the application of a low voltage. It is light-weighted, flexible, easily actuated, multi-directional applicable and requires simple manufacturing. Resultantly, IPMC has attracted scientists and researchers to analyze it further and consider it for any industrial and biomimetic applications. Presently, the research on IPMC is bi-directional oriented. A few groups of researchers are busy to find out the causes for the weaknesses of the material and to find out any remedy for them. The second class of scientists is exploring new areas of applications where IPMC material can be used. Although, the application zone of IPMC is ranging from micropumps diaphragms to surgical holding devices, this paper provides an overview of the IPMC application in biomimetic and biomedical field.


2009 ◽  
Vol 1190 ◽  
Author(s):  
Takuma Kobayashi ◽  
Takeshi Kuribayashi ◽  
Masaki Omiya

AbstractWe built up the way of fabricating IPMC actuator with palladium electrodes and we found that it showed large bending response than Au-plated IPMC actuator. An ionic polymer-metal composite (IPMC) consisting of a thin perfuorinated ionomer membrane, electrodes plated on both faces, undergoes large bending motion when a small electric field is applied across its thickness in a hydrated state. The characteristics of IPMC are ease of miniaturization, low density, and mechanical flexibility. Therefore, it is considered to have a wide range of applications from MEMS sensor to artificial muscle. However, there are problems on IPMC. First, its mechanical and electric characteristics have not been clarified because of the complex mechanism of the deformation. Second, it is high-priced because most of IPMC actuators use gold or platinum as electrodes. In order for IPMC actuator to be widely put to practical use, we should solve these problems. Hence, this research focuses on fabrication of IPMC actuator with palladium electrode, which is cheaper than gold or platinum, and evaluation of its mechanical properties such as its tip displacement. We fabricated IPMC consisting of a thin Nafion® membrane, which is the film with fluorocarbon back-bones and mobile cations, sandwiched between two thin palladium plates. The surface resistivity was 2.88±0.18Ω/sq., so it could be said to be enough small. Then, we observed its cross section by using FE-SEM. As a result, palladium plates were evenly coated and its thickness was about 30μm. Also, we carried out an actuation test for two kinds of IPMCs: one was fabricated by using Nafion®117 (thickness 183μm), the other was by Nafion®115 (thickness 127μm). In this test, the relationship between voltage (0˜4V) across its thickness and tip displacement for the cantilevered strip of the IPMC was measured. Then we found that IPMCs showed large bending motion under a low electric field. When Nafion®117 sample was subjected to voltage of 1.5V, the ratio of the tip displacement to the sample length was 0.35, which was lager bending than Au-plated IPMC actuator, whose ratio of the tip displacement to the sample length was 0.12 [1]. When Nafion®115 sample was applied to 1.5V, the ratio of the tip displacement to the sample length was 0.22. Then, we found that Nafion®117 bended in a larger way than Nafion®115. Reference [1]Sia Nemat-Nesser and Yongxian Wu,”Comparative experimental study of ionic polymer-metal composites with different backbone ionomers and in various cation forms”, Journal of Applied Physics,93,5255 (2003)


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