Geometrically Programmable Multiresponsive 3-D Microsensors/Actuators

Stimuli-responsive 3-D microsensors/actuators hold vast potential for applications in wearable electronics, biomedical scaffolds, micro-electromechanical systems (MEMS) arrays, and swarm microrobots. However, the integrated design and fabrication of 3-D microsensors/actuators with geometric programmability remains a significant challenge. In this work, we present Al/Nitinol thermal bimorph microstructures, along with their integrated design and fabrication methods based on photolithography and film deposition techniques. These 3-D structures are both flexible and geometrically programmable, enabling a wide range of complex 3-D configurations to be achieved through planar design and allowing initial deformation amplitudes to be defined by mold-free heat treatment. The resulting microstructure exhibits excellent photothermal and electrothermal properties, demonstrating a linear and fast response performance under both tethered electrical actuation and untethered optical actuation. The proposed fabrication method supports compatible, miniaturized, precise, parallel, and high-throughput production, enabling microstructures with various configurations to be manufactured simultaneously on a single 4-in wafer. Our approach provides a novel design and fabrication paradigm for creating 3-D microsensors/actuators with outstanding stimuli-responsive and geometric programming capabilities at the submillimeter scale.