Multiwalled carbon nanotube/IPMC nanocomposite

Abstract

Biomimetic actuators that can produce soft-actuation but large force generation capability are of interest. Nafion, an effective ionomeric material from DuPont, has been shown to produce large deformation under low electric fields (<10V/mm). It is now generally accepted that such a response is caused by a direct electro-osmotic effect due to the existence and mobility of cations and subsequent swelling and de-swelling of the material. In this effort, multi-walled carbon nano-tube (MWNT)/Nafion nano-composites were prepared by casting in order to investigate the effect of MWNT loading in the range of 0 to 7 wt% on electromechanical properties of the MWNT/Nafion nano-composites. The measured elastic modulus and actuation force of the MWNT/Nafion nano-composites are drastically different, showing larger elastic modulus and improved electromechanical coupling, from the one without MWNT, implying that the effective MWNT loading is crucial in developing of high-performance biomimetic actuators. In this work, we also attempted to incorporate an equivalent circuit analysis to address the effect of capacitance and resistance of such MWNT/Nafion nanocomposites that would differ from conventional IPMCs.