Light‐Controlled Micromotors and Soft Microrobots

Stefano Palagi,Dhruv P Singh,Peer Fischer

doi:10.1002/adom.201900370

Abstract

AbstractMobile microscale devices and microrobots can be powered by catalytic reactions (chemical micromotors) or by external fields. This report is focused on the role of light as a versatile means for wirelessly powering and controlling such microdevices. Recent advances in the development of autonomous micromotors are discussed, where light permits their actuation with unprecedented control and thereby enables advances in the field of active matter. In addition, structuring the light field is a new means to drive soft microrobots that are based on (photo‐) responsive polymers. The behavior of the two main classes of thermo‐ and photoresponsive polymers adopted in microrobotics (poly(N‐isopropylacrylamide) and liquid‐crystal elastomers) is analyzed, and recent applications are reported. The advantages and limitations of controlling micromotors and microrobots by light are reviewed, and some of the remaining challenges in the development of novel photo‐active materials for micromotors and microrobots are discussed.

Highlights

Light is extremely versatile as it can be used to transmit both energy and information
Photoresponsive materials for microrobots Polymeric materials, elastomers, and hydrogels that respond to light with a mechanical deformation can be used as remotely controlled on-board actuators for microrobots
Soft microrobots controlled by structured light we summarize results on the development of soft microrobots based on photothermal liquid-crystal elastomers (LCEs) and controlled by structured light

Summary

Introduction

Light is extremely versatile as it can be used to transmit both energy and information. The light fields we used to control the actuation and locomotion of soft LCE-based microrobots are examples of structured light, that is, they consist of regular (and usually binary) light patterns.

Results

Conclusion