The first two micrographs illustrate a two-level titanium microstructure designed for micro-fluidic applications. The first level consists of large and shallow cavities linked by 40 µm channels. Arrays of 40 µm grooves were etched into the four square cavities to form the second level. The structure is well defined and the surface finish in the cavities and channels is very smooth.
Titanium microfluidic circuits can be sealed by diffusion bonding (next three side cuts micrograph). Bonding can be made either with a flat plate or with a mirror engraved circuit to obtain a quasi circular section. The junction obtained is unnoticable and pressure as high as 1000 bars can be applied into the resulting micro-tubes.