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This paper reports results on ionic EAP micromuscles converting electrical into micromechanical response in open‐air. Translation of small ion motion into large deformation in bending microactuator and its amplification by fundamental resonant frequency are used as tools to demonstrate that small ion vibrations can still occur at frequency as high as 1000 Hz in electrochemical devices. These results are achieved through the microfabrication of ultrathin conducting polymer microactuators. First, the synthesis of robust interpenetrating polymer networks (IPNs) is combined with a spincoating technique in order to tune and drastically reduce the thickness of conducting IPN microactuators using a so‐called “trilayer” configuration. Patterning of electroactive materials as thin as 6 μm is demonstrated with existing technologies, such as standard photolithography and dry etching. Electrochemomechanical characterizations of the micrometer sized beams are presented and compared to existing model. Moreover, thanks to downscaling, large displacements under low voltage stimulation (±4 V) are reported at a frequency as high as 930 Hz corresponding to the fundamental eigenfrequency of the microbeam. Finally, conducting IPN microactuators are then presenting unprecedented combination of softness, low driving voltage, large displacement, and fast response speed, which are the keys for further development to develop new MEMS.

Interpenetrating polymer networks can become successful actuators in the field of microsystems providing they are compatible with microtechnologies. In this letter, we report on a material synthesized from poly͑3,4-ethylenedioxythiophene͒ and polytetrahydrofuran/poly͑ethylene oxide͒ and microsized by decreasing its thickness to 12 m and patterning the lateral side using plasma etching at high etch rates and with vertical sidewalls. A chemical process and a "self degradation" are proposed to explain such etching rates. Preliminary actuation results show that microbeams can move with very large displacements. These microsized actuators are potential candidates in numerous applications, including microswitches, microvalves, microoptical instrumentation, and microrobotics.

Interpenetrating polymer networks (IPNs) based on nitrile butadiene rubber (NBR) as first component and poly(ethylene oxide) (PEO) as second component were synthesized and used as a solid polymer electrolyte film in the design of a mechanically robust conducting IPN actuator. IPN mechanical properties and morphologies were mainly investigated by dynamic mechanical analysis and transmission electron microscopy. For 1-ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMITFSI) swollen IPNs, conductivity values are close to 1 × 10−3 S cm−1 at 25 ° C. Conducting IPN actuators have been synthesized by chemical polymerization of 3,4-ethylenedioxythiophene (EDOT) within the PEO/NBR IPN. A pseudo-trilayer configuration has been obtained with PEO/NBR IPN sandwiched between two interpenetrated PEDOT electrodes. The robust conducting IPN actuators showed a free strain of 2.4% and a blocking force of 30 mN for a low applied potential of ±2 V.

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The synthesis and characterization of flexible solid polymer electrolytes (SPEs) based on interpenetrating polymer networks (IPNs) are discussed. IPNs were prepared from nitrile butadiene rubber (NBR) and poly(ethylene oxide) (PEO) using a two-step process. The NBR network was obtained by dicumyl peroxide cross-linking at high temperature and pressure. A free radical copolymerization of poly(ethylene glycol) methacrylate and dimethacrylate led to the formation of the PEO network within the NBR network. Polymerization kinetics were followed by dynamic mechanical analysis (DMA) for the NBR network and by Fourier transform spectroscopy in the near-and mid-infrared for the PEO network. IPN mechanical properties, examined using DMA and tensile strength tests, reveal an IPN elongation with a breaking point of 110%. IPN conductivities reach 7.4 Â 10 À7 S cm À1 at 30 °C when doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). Moreover, IPNs exhibit an ionic conductivity as high as 0.7 Â 10 À3 S cm À1 at 30 °C when swollen in N-ethylmethylimidazolium bis(trifluoromethanesulfonyl)imide ionic liquid (EMITFSI).

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