Efficient elastocaloric drive system enabled by constant-torque and work-recovery design

Elastocaloric cooling is a promising alternative to vapor-compression systems, offering high efficiency and reduced environmental impact. Despite significant advances in elastocaloric technology in recent years, limited attention has been given to the mechanical systems required to drive elastocaloric materials. Here we show a cam-disc-based elastocaloric drive system with integrated direct work recovery, synchronized by four phase-shifted elastocaloric elements. The system introduces a constant-torque driving approach that maintains nearly constant input power during operation. Experimental results demonstrate a nearly constant camshaft torque of 14.4 Nm and a mechanical-level work-recovery efficiency of about 70% at an actuation force of 40 kN. Numerical simulations further show that integrating force amplification mechanisms can reduce the required camshaft torque and increase work-recovery efficiency to up to 88%. These results demonstrate that efficient drive systems can be realized for elastocaloric devices, paving the way toward their practical deployment.