Liquid crystal elastomer composite-based photo-oscillator for microrobots
Pengju Shi, Yusen Zhao, Zixiao Liu, Ximin He
Abstract
In recent years, photoactive materials have attracted extensive interest in microrobots for their attractive abilities of untethered and tunable control with light. Conventional photo-oscillators based on Azo-containing liquid crystal network require complex surface alignment techniques and light sources with specific wavelengths and polarity, which limits their application in controlled autonomy. Here, we report a facile strategy to create self-oscillating microrobots powered and controlled by a wide spectrum of constant light. The oscillators are composed of a layer of candle soot (CS)-containing liquid crystal elastomer (LCE) attached to a layer of polydimethylsiloxane (PDMS). The strip-shaped oscillators with one end fixed can execute self-sustained oscillation through a self-shadowing mechanism. LCEs with CS as an excellent photo-absorber provides superior photothermal actuation, while PDMS with low viscoelasticity accelerates the actuation-recovery cycle of the oscillator. Our LCE composite photo-oscillators show tunable frequencies and amplitudes by structural and light intensity modulation, showing potential for autonomous soft robotic applications.