Microtransformers: Controlled microscale navigation with flexible robots

Abstract

Artificial microswimmers are a new technology with promising microfluidics and biomedical applications, such as directed cargo transport, microscale assembly, and targeted drug delivery. A fundamental barrier to realizing this potential is the ability to independently control the trajectories of multiple individuals within a large group. A promising navigation mechanism for "fuel-based" microswimmers -for example, autophoretic Janus particles -entails modulating the local environment to guide the swimmer, for instance by etching grooves in microchannels. However, such techniques are currently limited to bulk guidance. This Rapid Communication will argue that by manufacturing microswimmers from phoretic filaments of flexible shape-memory polymer, elastic transformations can modulate swimming behavior, allowing precision navigation of selected individuals within a group through complex environments.