Liquid-Nitrogen Micropillar-Wick Cooling for Cryogenic Electronics: A Numerical Study of Thermal Performance and Capillary Dry-Out Limits
Abstract
Cryogenic computing technologies are maturing rapidly, but heat removal remains a key challenge when increasing the device density and operating power. Two-phase evaporative cooling is a promising approach to solve this issue, because it can dissipate high heat fluxes while maintaining small temperature rises. Here, we numerically investigate liquid-N2-filled silicon micropillar wicks as a capillary-fed thin-film evaporation concept for cryogenic electronics. The model combines Young-Laplace meniscus calculations, Hertz-Knudsen-Schrage evaporation, unit-cell heat-transfer and liquid-flow simulations, and an array-level thermal and capillary-flow model. For a representative geometry with a pillar diameter of 10 μm, pitch of 24 μm, and pillar height of 75 μm at an applied heat flux of 20 W cm−2, the predicted chip-temperature rise is approximately 2.7 K. This is substantially below the estimated temperature rises for representative conduction cooling through an indium-interlayered copper heat sink and direct liquid-N2 immersion. The corresponding predicted single-fed dry-out length is approximately 2.7 mm, equivalent to an ideal double-fed coolable width of approximately 5.3 mm. The results indicate that local thermal performance is favorable, whereas lateral scalability is primarily constrained by capillary dry-out. An approximate capillary-viscous scaling relation provides a compact framework for comparing dry-out limits across working fluids and related wick geometries and for identifying strategies to extend capillary-fed transport.
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BibTeX
@misc{mende2026liquidnitrogen,
title = {{Liquid-Nitrogen Micropillar-Wick Cooling for Cryogenic Electronics: A Numerical Study of Thermal Performance and Capillary Dry-Out Limits}},
author = {Felix Mende and Marcus Wislicenus and Dianping Jiang and Munehiro Tada and Lukas M. Eng},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.21639},
eprint = {2609.21639},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.21639},
}
RIS
TY - UNPB
TI - Liquid-Nitrogen Micropillar-Wick Cooling for Cryogenic Electronics: A Numerical Study of Thermal Performance and Capillary Dry-Out Limits
AU - Felix Mende
AU - Marcus Wislicenus
AU - Dianping Jiang
AU - Munehiro Tada
AU - Lukas M. Eng
PY - 2026
DA - 2026/09/18
PB - arXiv
DO - 10.48550/arxiv.2609.21639
UR - https://arxiv.org/abs/2609.21639
AB - Cryogenic computing technologies are maturing rapidly, but heat removal remains a key challenge when increasing the device density and operating power. Two-phase evaporative cooling is a promising approach to solve this issue, because it can dissipate high heat fluxes while maintaining small temperature rises. Here, we numerically investigate liquid-N_2-filled silicon micropillar wicks as a capillary-fed thin-film evaporation concept for cryogenic electronics. The model combines Young-Laplace meniscus calculations, Hertz-Knudsen-Schrage evaporation, unit-cell heat-transfer and liquid-flow simulations, and an array-level thermal and capillary-flow model. For a representative geometry with a pillar diameter of 10 μm, pitch of 24 μm, and pillar height of 75 μm at an applied heat flux of 20 W cm^−2, the predicted chip-temperature rise is approximately 2.7 K. This is substantially below the estimated temperature rises for representative conduction cooling through an indium-interlayered copper heat sink and direct liquid-N_2 immersion. The corresponding predicted single-fed dry-out length is approximately 2.7 mm, equivalent to an ideal double-fed coolable width of approximately 5.3 mm. The results indicate that local thermal performance is favorable, whereas lateral scalability is primarily constrained by capillary dry-out. An approximate capillary-viscous scaling relation provides a compact framework for comparing dry-out limits across working fluids and related wick geometries and for identifying strategies to extend capillary-fed transport.
ER -