Design and fabrication of hybrid bi-modal wick structure for heat pipe application

A new hybrid bi-modal wick structure was designed and fabricated in this study with the objective to simultaneously enhance performance in capillary pumping, permeability and evaporative heat transfer. Utilizing substrates with large pores and sintered powders, a highly integrated bi-modal wick structure was created with small pores lining the walls of the large pores. This unique structure can be tailored to a number of different configurations, including uniform, radial and axially varied pore morphologies. Tests of heat pipes containing the bi-modal wick structure in various configurations revealed increases in effective thermal conductivity by as much as 400% as compared to baseline heat pipes containing monolithic wick materials such as copper mesh.