FIG. 2.

The structure and characterization of round-shape micro-pumps. (a) Two bearings mounted on T-shape arm squeezing on a PDMS made chip with a circular track. (b) The photograph of a device. (c)–(e) The outflow stability is improved with channels using curved inlet/outlet joints and the buffer chamber. (d) A modified channel pattern with rounded in/outlet junctions shows improved outflow consistency. (e) The optimized channel pattern with additional buffer-chamber shows ideal uniform outflow. (f) The outflow volume with time at four rotating speeds. (g) Flow rate shows perfect linearity between rotation speed and flow rate.