Carbon nanotube-based dielectric elastomer for biomimetic actuators

Abstract

Conventional actuators such as geared servos suffer drawbacks in utilizing them in robots which work closely with humans. Dielectric elastomer actuators (DEAs) overcome these challenges since they can realize natural motion patterns which are inspired by those of human muscle. To date, fabrication of such bio-mimetic soft actuators is hindered by limited electrical conductivity of the electrode materials. We aimed at developing highly conductive multi-wall carbon nanotube/polydimethylsiloxane (MWCNT/PDMS) composites for use in DEA electrodes and to develop a simple single layer actuator fabricated with these improved composites. To this end, we proposed a method to increase the dispersion of MWCNTs in PDMS and to increase the electric conductivity of the composite. Our results showed that simple crushing of the composites in addition to the use of naphthalene/toluene improved the dispersion of MWCNTs in PDMS and enhanced the DC electric conductivity of the composite. We also proposed a simple conceptual design and developed a single layer DEA based on these improved composites.