On-chip thermal management of hotspots using a perspiration nanopatch

A cooling mechanism based on evaporation from thin liquid films is utilized for thermal management of hotspots combining efficient heat and mass transfer techniques. Dissipation of large heat fluxes from small form-factor areas is made possible by minimizing the thermal resistance across the evaporating liquid film. This is achieved by maintaining a very thin film (similar to 15 mu m) of coolant by capillary confinement using a nano-porous membrane (similar to 10 mu m). At the same time, evaporation is promoted by using jet impingement of dry air on the membrane. Based on these underlying ideas, a MEMS device called a 'perspiration nanopatch' is presented. The design and fabrication process of this micro-fluidic device is described along with experimental performance characterization under different operating conditions. Dissipation of heat fluxes in excess of 600 W cm(-2) is demonstrated with heat transfer coefficients approaching 0.1 MW m(-2) K-1 for surface temperatures well below the saturation temperature of the working fluid.