Spatially Patterned Laser-Induced Graphene for Enhanced Pool Boiling Heat Transfer

Efficient thermal management of high-heat-flux systems requires boiling surfaces that promote nucleation without compromising liquid replenishment. Laser-induced graphene (LIG) is attractive for this purpose because its porous, graphene-like morphology provides abundant nucleation sites and can be formed through a simple laser-writing process. In this study, spatially patterned LIG microchannels were fabricated on silicon heating substrates to clarify how the arrangement of nucleation-active LIG domains affects saturated water pool boiling. Bare silicon, fully LIG-covered, and LIG-patterned surfaces were compared to separate the contribution of LIG morphology from that of spatial organization. The LIG-modified surfaces promoted early boiling incipience, confirming the nucleation activity of the porous LIG layer. However, the developed boiling response depended strongly on the spacing between LIG domains, with narrow-pitch patterns providing the most favorable heat transfer performance. These results show that patterned LIG can enhance boiling heat transfer by coordinating nucleation activation, vapor removal, and liquid replenishment, demonstrating its potential as a scalable boiling surface for high-heat-flux thermal management.