A planar torsion spring has outer and inner hubs connected by a set of beams that are capable of bending to provide torsional compliance when the outer hub is rotated with respect to the inner hub. Each beam is fixed to the outer hub at one end and is attached to the inner hub at its other end by a pin and slot. Slots may be curved. The spring is capable of deflecting to ±π6radians and providing 100 N·m of torque. Bearings may be located at the interface between each pin and slot. Beams may have variable width. In a method of fabrication, the design dimensions, material, and slot geometry of the planar torsion spring can be parameterized to design springs that meet specific requirements for different applications. In addition to quantifying performance, the models provide the foundation for further weight, efficiency, and performance optimization.
