Biocompatible Electromechanical Actuators Composed of Silk‐Conducting Polymer Composites

Single-component, metal-free, biocompatible, electromechanical actuator devices are fabricated using a composite material composed of silk fibroin and poly(pyrrole) (PPy). Chemical modification techniques are developed to produce free-standing films with a bilayer-type structure, with unmodified silk on one side and an interpenetrating network (IPN) of silk and PPy on the other. The IPN formed between the silk and PPy prohibits delamination, resulting in a durable and fully biocompatible device. The electrochemical stability of these materials is investigated through cyclic voltammetry, and redox sensitivity to the presence of different anions is noted. Free-end bending actuation performance and force generation within silk-PPy composite films during oxidation and reduction in a biologically relevant environment are investigated in detail. These silk–PPy composites are stable to repeated actuation, and are able to generate forces comparable with natural muscle (>0.1 MPa), making them ideal candidates for interfacing with biological tissues.

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