Correlation of capacitance and actuation in ionomeric polymer transducers

Layer-by-layer self-assembled conductor network composites in ionic polymer metal composite actuators with high strain response

“…[4][5][6][7] Since then, much research effort has been devoted to this class of EAPs with the objective of further improving the electromechanical performance properties such as the actuation speed, strain level, and efficiency. [4][5][6][7][8][9][10][11][12][13][14] Figure 1͑a͒ illustrates schematically such an ionic polymer bending actuator in which the accumulation and depletion of cations at the cathode and anode, respectively, create bending of the ionic polymer membrane under an electrical signal. Experimental results have indicated that a high population of the excess charges at the electrodes is highly desirable in order to generate high electromechanical actuation.…”

“…To realize that, porous electrodes which offer large electrode areas in contact with ionomers are often utilized in this class of actuators. [4][5][6][7][8][9][10][11][12][13][14] One widely investigated ionic polymer metal composite ͑IPMC͒ uses a chemical reduction method to deposit precious metals to Nafion ͑a perfluorosulfonated ionomer developed by DuPont͒ membrane surfaces, in which nanosized metal particles penetrate into the Nafion membrane to form porous electrodes. [5][6][7]11,14 More recently, a direct assembly method in which conductive nanoparticles were mixed with a Nafion ͑or an ionomer͒ solution and this mixture is directly deposited on the Nafion ͑or an ionomer͒ membrane to fabricate IPMC was developed.…”

“…[5][6][7]11,14 More recently, a direct assembly method in which conductive nanoparticles were mixed with a Nafion ͑or an ionomer͒ solution and this mixture is directly deposited on the Nafion ͑or an ionomer͒ membrane to fabricate IPMC was developed. 8,9,12,13 The direct assembly method to fabricate IPMCs is attractive because it allows for the use of a broad range of nanosized conductors for the electrodes such as carbon nanotubes. 13 It also simplifies the fabrication process of IPMCs and enhances actuator manufacturing repeatability.…”

“…13 It also simplifies the fabrication process of IPMCs and enhances actuator manufacturing repeatability. 8,9,12,13 Illustrated in Fig. 1͑b͒ is a typical bimorph ͑bending͒ actuator thus developed, which in general has a three layer structure, i.e., two porous composite electrode layers, which are referred to as the conductor network composite ͑CNC͒ and generate strain under applied voltage, separated by a neat ionomer layer.…”

“…RuO 2 /Nafion nanocomposite ionic polymer conductor network composites ͑IP-MCs͒ have been investigated extensively and have shown high strain response among the IPMCs developed. [4][5][6][7][8][9][10][11][12][13] For the IPCNCs investigated in this paper, the commercial Nafion film NR-211 of thickness 25 m was chosen as a͒ Electronic mail: rezam@vt.edu. the ionomer layer in Fig.…”