Hotspot thermal management using thermoelectric and microchannel hybrid cooling at transient and steady states

• Thermoelectric and microchannel hybrid cooling is comprehensively measured. • Measure the responses to power changes of various amplitudes and frequencies. • Hybrid cooler outperforms microchannel in hotspot cooling up to 1.38 kW/cm 2 . • Temperature rise is reduced by 75 % under a heating power density of up to 800 W/cm 2 . Electronics and optoelectronics such as laser diodes, light-emitting diodes, and photonic chips require precise temperature control to ensure reliable performance. However, conventional microchannel cooling has long response times to dynamic changes in heating loads, leading to undesirable temperature rises in temperature-sensitive devices. Here, a hybrid cooling module combining a thermoelectric cooler with a microchannel is reported. This module enables zero or negative thermal resistance, and fast control of hotspot temperature. A steady-state thermal resistance model is constructed from experimental data to analyze and predict the cooling performance of the cooling module. Using the thermal resistance of a simple microchannel module as the baseline, the maximum applicable heating power density of the hybrid cooling module is determined as 1380 W/cm 2 . Below this threshold, the hybrid cooling module outperforms the simple microchannel heat sink in removing heat from the hotspot and controlling the hotspot temperature. Additionally, the hybrid cooling module demonstrates excellent dynamic temperature control performance. Under sudden stepwise or pulsed increases, and periodic fluctuations in power density with high-load power densities less than 800 W/cm 2 , the maximum temperature changes with the hybrid cooling module can be reduced by more than 75 % compared to a simple microchannel heat sink. This work provides an experimental protocol for determining applicable heating power densities and maximum temperature rises for designing thermal management systems utilizing thermoelectric and microchannel hybrid cooling.