Programmable Biomimetic Actuators via Heat-Assisted Thin-Film Transfer and Direct Micropatterning

Abstract

Thin-film actuators have emerged as promising prime movers in miniature robotic systems, but conventional fabrication methods often constrain both their mechanical performance and their capacity for complex, programmable shape-morphing. Specifically, for actuating materials synthesized via electrodeposition, a conductive metal passive layer or interlayer is typically required. This rigid metal layer lowers actuation performance, increases fabrication complexity and costs, and complicates the spatial patterning necessary for multidirectional actuation. To overcome these limitations, a heat-assisted thin-film transfer method is developed to fabricate multistimuli-responsive birnessite-type manganese dioxide (δ-MnO2)/PET bilayer actuators. Crucially, this dry transfer technique facilitates a straightforward micropatterning route to selectively create highly customizable actuating hinges. By controlling the spatial orientation of these transferred δ-MnO2 patterns, programmable macroscopic motions─such as cylindrical curling and helical twisting─are successfully achieved. Alongside this spatial programmability, the actuators maintain high performance, exhibiting a curvature change of 1.5 cm–1 under a low light intensity of 80 mW·cm–2 and 1.1 cm–1 when stimulated by organic vapor. Utilizing this versatile manufacturing platform, biomimetic architectures are constructed, including a flower-like soft gripper capable of on-demand object manipulation. Ultimately, this fast, scalable, and low-cost transfer process opens a pathway for designing and programming intelligent soft-robotic systems.