Snapping for 4D‐Printed Insect‐Scale Metal‐Jumper

Abstract

AbstractThe replication of jumping motions observed in small organisms poses a significant challenge due to size‐related effects. Shape memory alloys (SMAs) exhibit a superior work‐to‐weight ratio, making them suitable for jumping actuators. However, the SMAs advantages are hindered by the limitations imposed by their single actuator configuration and slow response speed. This study proposes a novel design approach for an insect‐scale shape memory alloy jumper (net‐shell) using 4D printing technology and the bistable power amplification mechanism. The energy variations of the SMA net‐shell under different states and loads are qualitatively elucidated through a spring‐mass model. To optimize the performance of the SMA net‐shell, a non‐contact photo‐driven technique is employed to induce its shape transition. Experimental investigations explore the deformation response, energy release of the net‐shell, and the relationship between the light power density. The results demonstrate that the SMA net‐shell exhibits remarkable jumping capabilities, achieving a jump height of 60 body lengths and takeoff speeds of up to 300 body lengths per second. Furthermore, two illustrative cases highlight the potential of net‐shells for applications in unstructured terrains. This research contributes to miniaturized jumping mechanisms by providing a new design approach integrating smart materials and advanced structures.