A Miniature Rotary Electrostatic Clutch for Assigning Multi‐Degrees of Freedom to Insect‐Scale Robots

Abstract

Insect‐scale crawling robots can navigate confined environments mainly for passive tasks such as search, rescue, and surveillance. Adding actuated degrees of freedom to manipulate the environment can substantially expand the range of tasks that the insect‐scale robot can perform, which is, however, prohibitive due to the added volume and weight. Herein, a miniature rotary electrostatic clutch is presented such that it enables reconfigurable motion by selectively distributing the power of a single motor while embedded at multiple joints. In order to facilitate a compact clutch with a large locking torque, cutting patterns in the electrostatic clutch layer are incorporated. The segmented layer allows large out‐of‐plane displacement, thereby increasing the contact area between layers during engagement. Therefore, compact (20 mm), lightweight (0.4 g) clutches achieve a locking torque of 83.4 mNm, 4 times larger than a clutch without the pattern. Adding a single motor, seven clutches, and four clutch‐layer pairs enables independent drive of six additional joints without significantly increasing size or mass. This approach allows insect‐scale robots to perform variety tasks such as object manipulation, obstacle negotiation, and shape transformation. This method offers an efficient way to embed multiple actuated degrees of freedom in miniature robots, therefore enhancing their mobility and functionality.