Nanowire-integrated microporous silicon membrane for continuous fluid transport in micro cooling device

Abstract

We report an efficient passive micro pump system combining the physical properties of nanowires and micropores. This nanowire-integrated microporous silicon membrane was created to feed coolant continuously onto the surface of the wick in a micro cooling device to ensure it remains hydrated and in case of dryout, allow for regeneration of the system. The membrane was fabricated by photoelectrochemical etching to form micropores followed by hydrothermal growth of nanowires. This study shows a promising approach to address thermal management challenges for next generation electronic devices with absence of external power. V

Liquid-Vapor Phase-Change Heat Transfer on Functionalized Nanowired Surfaces and Beyond

“…The advances in the fabrication of micro/nanostructured surfaces have led to exciting improvements in liquid-vapor phase-change heat transfer. Benefiting from the advances in phase-change heat transfer enhancement using micro/nanostructured surfaces, heat transfer capability and thermal efficiency of some two-phase thermal management devices such as heat pipes, vapor chambers, and micro-channels, 2,104,[106][107][108]145,153,[319][320][321] have been significantly improved. Various nanostructures have been introduced to suppress the flow instability and improve flow boiling heat transfer performance in micro-channels, 104,[106][107][108]145,322,323 Significantly enhanced flow boiling performance has been demonstrated, including an early ONB, a delayed onset of flow oscillation, suppressed oscillating amplitude of temperature and pressure drop, and augmented HTC.…”

Micromachined passive phase-change cooler for thermal management of chip-level electronics

“…To fabricate the multiple straight microchannel arrays through the Si substrate, photoelectrochemical etching was used in this study for high-aspect-ratio trenches [40,41]. Once the porous Si wick is fabricated, ZnO nanowires can be synthesized on the wick surface by hydrothermal method at low temperature [26]. The detail fabrication flow of the nanowire-integrated coherent porous Si wick layer is shown in Fig.…”

“…In this study, the coherent Si wick, which consists of vertically aligned cylindrical micropore arrays and decorated nanowires, was fabricated to allow the pinned liquid meniscus at the end of pores to overflow out of the micropores so that coolant is able to remove the heat flux by touching the evaporator surface, as seen in Fig. 2(b) [26]. The reservoir layer includes three main sections: a coolant reservoir, microchannels, and an intermediate chamber, as seen in Fig.…”

Self-Transport of Condensed Liquid in Micro Cooling Device Using Distributed Meniscus Pumping

“…One key issue for achieving continuous and reliable cooling operation without dryout limitation is to enhance capillary force over surface tension in channels. In our previously reported study, continuous feeding of the coolant through the wick against gravity was achieved by introducing nanowires on the periphery of the aligned micropores to drive the coolant out of the vertical channels by extended capillary action . Decorated nanowires allowed coolant to surge up and spread across the entire wick surface, keeping the evaporator surface wetted and hydrated during device operation.…”