Light-triggered multi-joint microactuator fabricated by two-in-one femtosecond laser writing

Micrometer scale soft robots integrating multiple microjoints to achieve multideformation modalities are desirable owing to their potential applications. Here the authors develop microactuators possessing multi-deformable microjoints composed of hydrogel and metal nanoparticles printed by a two-in-one femtosecond laser strategy and providing short response times and low actuation power. Inspired by the flexible joints of humans, actuators containing soft joints have been developed for various applications, including soft grippers, artificial muscles, and wearable devices. However, integrating multiple microjoints into soft robots at the micrometer scale to achieve multi-deformation modalities remains challenging. Here, we propose a two-in-one femtosecond laser writing strategy to fabricate microjoints composed of hydrogel and metal nanoparticles, and develop multi-joint microactuators with multi-deformation modalities (>10), requiring short response time (30 ms) and low actuation power (<10 mW) to achieve deformation. Besides, independent joint deformation control and linkage of multi-joint deformation, including co-planar and spatial linkage, enables the microactuator to reconstruct a variety of complex human-like modalities. Finally, as a proof of concept, the collection of multiple microcargos at different locations is achieved by a double-joint micro robotic arm. Our microactuators with multiple modalities will bring many potential application opportunities in microcargo collection, microfluid operation, and cell manipulation.

Automated summary

The authors developed micrometer scale soft robots with multiple microjoints that can achieve different deformation modes, utilizing a two-in-one femtosecond laser strategy to create microactuators composed of hydrogel and metal nanoparticles. These microactuators have short response times and require low actuation power. The ability to integrate multiple microjoints into soft robots at the micrometer scale represents a significant challenge.