Fabrication of titanium microchannels using laser-assisted thermochemical wet etching

A fabrication method of titanium microchannels of an aspect ratio up to 16 and channel width of 10–30 μm is developed using laser-assisted thermochemical wet etching. For the fabrication of deep channel, the workpiece was repeatedly etched over the same path with the control of process parameters. The cross-sectional profile of the microchannel varied between a V shape and a U shape, depending largely upon the laser beam power and etchant concentration. Bubble formation characteristics that influence significantly on the surface quality and process stability are investigated. It is demonstrated that high-aspect-ratio metallic microchannels with different cross-sectional profiles and sizes can be fabricated by properly controlling the process parameters.