Photothermal actuation of bioinspired soft robotic microdevices

Microscopic soft devices that can actively interrogate and precisely perturb the biological microenvironment through physical and chemical interactions can revolutionize therapy and biomedical research. Inspired by the architecture and actuation principles of skeletal muscle, we aim to physically couple hierarchical assemblies of nanoactuators with rationally-designed compliant mechanisms and develop modular soft robotic microdevices that can perform dexterous micromanipulation. The key idea is to combine the rapid and efficient transduction of energy via the plasmonic photothermal effect at nanoscale with colloidal self-assembly and spatially modulated optofluidic additive manufacturing processes at microscale.

Universal soft robotic microgripper

We have developed a soft robotic microgripper that consists of a smart actuated microgel connected to a spatially photopatterned multifunctional base. When pressed onto a target object, the microgel component conforms to its shape, thus providing a simple and adaptive solution for versatile micromanipulation without the need for active visual or force feedback. By molding itself around the cargo, the microgripper not only builds geometric constraints but also generates static friction from normal stresses at contact. This new configuration is locked in place by utilizing the shape-memory property of the alginate microgel. An untethered version of gripper is developed that allows remote control of the position using magnetic actuation and the contractile state of the microgel using photothermal actuation.