TwistER—Prototype of Twistocaloric Cooling Device with Energy Recovery Based on Natural Rubber

Elastocaloric cooling is a cutting-edge technology with the potential to advance cooling methods by replacing harmful refrigerants, improving energy efficiency, and addressing global warming [1]. Recently, natural rubber has been identified as a promising solid-state refrigerant [2-4]. This material demonstrates exceptional elastocaloric performance because of its ability to crystallise under strain, and initial prototypes made from natural rubber have already been developed [5, 6]. Recent findings indicate that twisting these materials, rather than just stretching them uniaxially, significantly enhances the cooling effect [7].

We present TwistER, a novel gas-free cooling technology that uses natural rubber refrigerants. TwistER incorporates both uniaxial stretching and twisting to maximise cooling power, cooling a closed heat exchanger water circuit. The design separates hot and cold sinks, simplifying heat exchanger design and boosting efficiency. Energy consumption is minimised through energy recovery principles, with a secondary cycle operating in antiphase mode. TwistER demonstrates the feasibility of using natural rubber for twistocaloric cooling, achieving significant undercooling with minimal mechanical stresses, all through low-cost and compact technology.

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