Enhanced heat transfer and liquid rewetting of a robust 3D bi-conductive surface with hydrophilic/hydrophobic patterned wicking structure

Sintering technique is widely applied in various thermal management applications. Insights gained into capillary-driven fluid transport and bubble dynamics can inform the development of next-generation wick structures for heat pipes and vapor chambers. A new, simple, cost-effective, and durable bi-conductive surface has been developed with hydrophilic/hydrophobic patterned wicking structure that exhibits outstanding pool boiling heat transfer performance. Fabricated through a simple and economical process, this surface achieves even greater heat transfer enhancement compared to other complex and expensive fabrication methods of existing porous sintered and hydrophobic patterned surfaces. The inherent bi-conductive and biphilic characteristics also guarantee long-term durability, effectively addressing the issue of degradation observed in chemically treated hydrophobic patterned surfaces. The copper and PTFE hybrid structure exhibits high wicking performance and biphilic properties, leading to a remarkable 210% enhancement in Critical Heat Flux (CHF) and a substantial 460% increase in Heat Transfer Coefficient (HTC). The CHF improvement is attributed to the combined effects of the hydrophobic pattern and surface wickability, which facilitate effective liquid–vapor separation and rapid fluid replenishment to the dry area. Our results also show that the joint action of the two factors shows a better effect on the CHF enhancement than the effect of the two alone. Moreover, the HTC enhancement is driven by a higher bubble departure frequency achieved under the combined benefits of eliminating the waiting time on the hydrophobic patterned area and rapid liquid replenishment to the nucleation region on the porous structure.