Snapping Actuators with Asymmetric and Sequenced Motion
2026-02-20 • Robotics
Robotics
AI summaryⓘ
The authors created a soft dome-shaped actuator that snaps in an uneven way due to its shape, allowing it to move asymmetrically. They tested this using computer simulations and real experiments, finding reliable and repeatable motions. By connecting four of these snapping actuators with air pressure, they built a small four-legged robot that moves in coordinated waves using just one air input. The robot's speed depends on how fast the snapping happens, reaching up to about 7 cm per second. This work shows how shape-based snapping can control motion efficiently in soft robots.
snapping instabilitysoft actuatorfinite element simulationasymmetric deformationpneumatic networkquadrupedal robotlocomotionfrequency-dependent performance
Authors
Xin Li, Ye Jin, Mohsen Jafarpour, Hugo de Souza Oliveira, Edoardo Milana
Abstract
Snapping instabilities in soft structures offer a powerful pathway to achieve rapid and energy-efficient actuation. In this study, an eccentric dome-shaped snapping actuator is developed to generate controllable asymmetric motion through geometry-induced instability. Finite element simulations and experiments reveal consistent asymmetric deformation and the corresponding pressure characteristics. By coupling four snapping actuators in a pneumatic network, a compact quadrupedal robot achieves coordinated wavelike locomotion using only a single pressure input. The robot exhibits frequency-dependent performance with a maximum speed of 72.78~mm/s at 7.5~Hz. These findings demonstrate the potential of asymmetric snapping mechanisms for physically controlled actuation and lay the groundwork for fully untethered and efficient soft robotic systems.