Screwed micro fluidic connections fabricated by ultrasonic hot embossing and welding

Recent connection methods to micro fluidic chips, such as gluing tubes and hoses into orifices or pressing a gasket on them have been studied to improve the common problem to establish a connection of the macroscopic world to a fluidic micro system. In this study, micro fluidic chips from polycarbonate plates with screwed connections have been fabricated by ultrasonic hot embossing and welding, both as in plain and out of plain arrangements. To fabricate threads in the polymer plates, an M3 screw was ultrasonically welded into a hole in the chip and the screw was turned out after the process. The tightness of micro channels and fittings was proven by pumping ink and yeast cells through the micro channels and by applying air pressure of up to 700 kPa, respectively. The process introduced here is especially advantageous because sealing micro channels and welding in micro fluidic screwed connections is done in a single fabrication step.