Scientific Reports (Jul 2024)

Development of a fully packaged passive thermal regulator

  • Seung Won Park,
  • Junhui Li,
  • Patricia B. Weisensee

DOI
https://doi.org/10.1038/s41598-024-67758-4
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 12

Abstract

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Abstract Thermal regulators are devices that can adopt either the role of a thermal insulator or a thermal conductor, depending on the thermal input conditions, and play an increasingly important role in thermal management systems. In this study, we developed and tested a new passive thermal regulator design that operates around room temperature and achieves high switching ratios. Our regulator is structurally integer, scalable, orientation-independent, resistant to vibration, and can be easily integrated into existing thermal management solutions. The working principle of the passive regulator is simple yet effective, whereby an aluminum plug attached to a bimetallic strip enters and exists a wedge-shaped gap between two conductors. We demonstrate a switching ratio of ≈ 50 $$(_{ - 8}^{ + 34} )$$ ( - 8 + 34 ) :1 for a fully packaged prototype (≈ 320 (± 200):1 for a non-packaged regulator) operated in the open laboratory environment. Through geometric optimization using numerical simulations, we show that a switching ratio of ≈ 100 $$(_{ - 15}^{ + 18} ){ }$$ ( - 15 + 18 ) :1 can be easily obtained, which can be further increased by increasing the cross-sectional area of the input conductor, hence increasing the ON-state heat transfer rate. The OFF-state thermal performance is much less sensitive to the size of the conductor, making the device highly scalable.