Femtosecond‐Laser‐Direct‐Writing Micro‐Scale Soft Actuators with Controllable Shape Morphing

Abstract

AbstractMicro‐scale soft actuators with controllable shape‐morphing are the focus of advanced technological fields, ranging from advancing sensing, industrial robotics, and digital manufacturing to medical devices. Particularly, there is a growing interest in the scientific community to leverage liquid crystal polymers (LCPs) to fabricate such soft actuators, because LCPs can offer reversible, programmable deformations under external stimuli. However, pattern micromachining of LCPs into micro‐scale remains a daunting challenge. Herein, a femtosecond laser direct writing (FsLDW) method for cross‐linked LCP (CLCP) microstructure construction is reported that enables arbitrary pattern machining with a minimum size of 40 µm and average heat‐affected zone (HAZ) below 8 µm through optimization of processing parameters. Light‐driven behaviors of CLCP microstructures are systematically characterized through analyzing the effects of film thickness, length‐width ratio, light irradiation time, incident angle, light intensity, and cutting direction on bending and twisting behaviors. Finally, a light‐driven micromirror system is demonstrated, which can achieve not only a controllable swing but also a rotation of the mirror surface with a maximum scanning frequency of ≈2 Hz.