Demonstrating kHz electromechanical response of ionic microactuators
Résumé
Ionic EAP micromuscles converting electrical energy into micromechanical response in open-air are presented. Translation of small ion motions into large deformations 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 1kHz in electrochemical devices. These results have been achieved through the microfabrication of ultrathin conducting polymer microactuators. First the synthesis of robust interpenetrating polymer networks (IPNs) has been combined with a spin-coating technique in order to tune and drastically reduce the thickness of conducting IPN microactuators. 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 (+/- 4V) are reported at a frequency as high as 930 Hz corresponding to the fundamental eigenfrequency of the microbeam. 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 of new MEMS. Finally, new considerations on process, contact positioning and direct integration will be discussed.
