Silver Coated Multifunctional Liquid Crystalline Elastomer Polymeric Composites as Electro-Responsive and Piezo-Resistive Artificial Muscles.

Liquid crystalline elastomers (LCEs) are a class of shape-changing polymers with exceptional mechanical properties and potential as artificial muscles/polymer actuators. In this study, multifunctional LCE actuators with strain sensing and joule heating responsivity are developed. LCEs are successfully synthesized using the thiol-ene two-staged michael addition polymerization (TMAP) method. The LCE films are further functionalized via sequential polydopamine (PDA) and silver electroless coating. It is found that the PDA coating enabled the anchoring of the Ag particles to the LCE, thereby enabling the electrical conductivity of the Ag-LCEs (<0.1 Ω cm). The studies confirm that the Ag/PDA coated LCEs can sense up to ≈30% strain, sense their own actuation strokes, and actuate at a rate of 1.83% s while lifting a weight ≈50 times its mass in response to a 12 V 2A DC current.