Etching of microfluidic cells

Microfluidic or Lab-on-Chip devices are utilizing microchannels etched in an inert material like glass. Glass etching can be done directly by the laser or by preparing some surface areas for etching and continuing the process with hydrofluoric acid. Every laser pulse creates an tiny dip. The depth of the dip is dependent on the intensity in focus and can be as shallow as 0.1 microns. Adding a flat layer on top creates capillaries small enough to have flow rates dependent on molecule size.