A ball valve micro-pump based on axially symmetrical nozzle fabricated by excimer laser micromachining technology

This paper presents a new type of ball valve micro-pumps with much simplified structure design and excellent performance. The key element in this micro-pump is a pair of ball valves implemented by confining a micro-ball within a nozzle. The nozzles are axially symmetrical with a specifically designed profile and are directly fabricated using excimer laser micromachining approaches. The ball valves are integrated with a flow chamber, an electromagnetically actuated PDMS membrane, and a coil. When passing an alternative current (AC) through the coil, the flow chamber is actuated to pump fluid flowing along one direction which is controlled by the ball valves. The performance of the proposed micro-pump is evaluated using an AC voltage in the range of 2-6 V and a frequency of 10-70 Hz. Experimental results show that a maximum flow rate of 389 μL/min and a maximum back pressure of 423 mm-H₂O are achieved. It offers a low-cost, simple, and effective solution for a wide range of microfluidic pumping applications.