Rotational Spring Design of Mechanical Metamaterials with Torsion‐Displacement Conversion and Compression‐Torsion Conversion

This work proposes a rotational spring design of mechanical metamaterials with torsion‐displacement conversion (TDC) and compression‐torsion conversion (CTC) behaviors by 3D printing. Based on the constant torsion angle design method, TDC structures with high utilization and symmetric design are derived, and the structures are the same as the CTC structures designed by the same method. Corresponding finite‐element simulations are performed, and the results show that with the increase of the coefficient K , the TDC efficiency increases, and the CTC efficiency decreases. The TDC efficiency decreases linearly with the increase of the torsion angle, and the CTC efficiency increases with the increase of the strain. Principle models of the generator, stiffness regulating structure, and robot arm based on the rotational spring have been assembled. The rotational spring has excellent TDC and CTC characteristics and has great application potential in power generation, stiffness regulation, and actuator.