Programmable gear-based mechanical metamaterials

A design paradigm to create robust robotic metamaterials using versatile gear clusters is demonstrated. It enables intriguing programmability of elastic properties and shape while preserving stability for intelligent machines. Elastic properties of classical bulk materials can hardly be changed or adjusted in operando, while such tunable elasticity is highly desired for robots and smart machinery. Although possible in reconfigurable metamaterials, continuous tunability in existing designs is plagued by issues such as structural instability, weak robustness, plastic failure and slow response. Here we report a metamaterial design paradigm using gears with encoded stiffness gradients as the constituent elements and organizing gear clusters for versatile functionalities. The design enables continuously tunable elastic properties while preserving stability and robust manoeuvrability, even under a heavy load. Such gear-based metamaterials enable excellent properties such as continuous modulation of Young's modulus by two orders of magnitude, shape morphing between ultrasoft and solid states, and fast response. This allows for metamaterial customization and brings fully programmable materials and adaptive robots within reach.

Automated summary

This research demonstrates a design paradigm for creating robust robotic metamaterials using versatile gear clusters. The design allows for continuous tuning of elastic properties while maintaining stability and robust maneuverability, even under heavy loads. The gear-based metamaterials offer excellent properties such as tunable Young's modulus, shape morphing, and fast response.