A Self-Commutated Helical Polypyrrole Actuator Fabricated by Filament Patterning

Abstract

Reversible retaining attachment is a universal task in which bioinspired soft robotic solutions in the form of a helix may come in handy. In this letter, we propose an mm-scale non-metallic electroactive polymer (polypyrrole) helical actuator with a 3D multimode (elongation, rotation) actuation with elastomer-like anchorage retainment. The non-reconfigurable bonds formed by electrodepositing polypyrrole on a temporary 3-D coiled-filament template programmed its shape. Filament-induced fracturing during template removal finalized the helix shape. Anisotropy introduced in the synthesis process yielded a helix with 8% linear strain, up to ≈180° tip rotation, and 63% structural strain. The self-commutated spirals of the helix played a critical role in the super-structure of the actuator with charge transfer and commutation-induced bi-stable motion. The potential applications include reversible compliant anchoring solutions for biomaterial (e.g., bacteria) scaffolding in bio-hybrid robots.