Patent ID: 7828046

Claim:
A wicking material, comprising; a porous metal substrate of foam, felt, mesh, or screen, said porous metal substrate having a length defining an axial direction and a thickness defining a radial direction transverse to said axial direction, the porous metal substrate enclosing a vapor flow passageway in said axial direction, said porous metal substrate defining first pores of a first size; and a porous sintered metal powder formed on the porous metal substrate, said porous sintered metal powder defining second pores of a second size; said porous sintered metal powder and said porous metal substrate forming a hybrid microstructure having said first pores of said first size and at least said second pores of said second size, said first size pores being larger than said second size pores, said second pore size being in a range selected to give capillary pumping of liquid, wherein a concentration of said second pores varies along said radial direction of said porous metal substrate in a spatially distributed manner, and furthermore in such a manner that a larger concentration of said second pores is located at a wick interface immediately adjacent to the vapor flow passageway; wherein said porous sintered metal powder defining said second pores is attached to walls of said first pores whereby said second pores are incorporated onto the walls of the first pores so as to define a structure with no layer interfaces.