Unidirectional heat and fluid transfer performances of a thermal diode with fishbone-microstructure wicks

Abstract

With the rapid development of high-performance electronics in aerospace, communication, and energy storage systems, the huge heat flux poses an increasing threat to the safety of electronic devices. In contrast to conventional external cooling strategies, on-chip heat dissipation with targeted directional regulation emerges as a promising solution for extreme thermal conditions induced by thermal shock and elevated heat flux. Differing from the existing cooling devices that depend on the temperature gradient, this thermal diode can realize the predetermined unidirectional heat transfer with a low thermal resistance by modulating the fluid flow resistance, effectively preventing heat reflux and the consequent overheating of electronic components. The correlation between flow performance and heat transfer efficacy has been analyzed. When the temperature of the condenser surpasses that of the evaporator, heat transfer in the reverse direction is inhibited, safeguarding electronic components from overheating. Experimental results reveal that the thermal diode exhibits a remarkable thermal dipolarity of 4.05, coupled with a flow dipolarity of 21, ensuring resilience against severe thermal shock in extreme environments. The proposed heat dissipation strategy offers valuable insights for the design of directional heat dissipation devices tailored to meet the extreme thermal management demands of modern electronics.