Sodium Alginate Composite Films Incorporated by Glycerol and Oxidized MWCNT for Driving Dielectric Elastomers

Abstract

Dielectric elastomer actuators (DEAs) are widely used in many fields such as bionic robotics and wearable electronics. Due to a high elastic modulus and a poor flexibility, pure sodium alginate (SA) film constrains the deflection of DEA and is not suitable for using as the electrode. By incorporating the plasticizer of glycerol and the conductive fillers of oxidized multi-walled carbon nanotubes (MWCNTs), the resultant MWCNT/SA composite film exhibits a high flexibility and a high electrical conductivity (129 Ω·sq.⁻¹), enabling it as the electrode to drive the dielectric matrix of VHB4910 for out-of-plane actuations. Driven by a relatively low electric field of 20.8 V/μm, the MWCNT/SA electrode DEA presents a desired areal strain of 3.8%. Long-term actuations reveal that the MWCNT/SA electrode DEA exhibits very stable electromechanical behaviors with a relative displacement shift (RDS) of 19.8% over 500 cycles, which is far lower than the commercial silicone electrode DEA, whose RDS is 127.8% under the same driven conditions.