Design, fabrication and characterization of an externally actuated ON/OFF microvalve

A magnetic microfluidic valve has been designed, fabricated and tested. Operation relies on the use of a permanent magnet which interacts with an electrodeposited layer of Co–Ni (soft magnetic material) on a V-shaped cantilever beam. The deflection caused by the magnetic forces opens or closes the fluid flow. The microvalve performance has been optimized by means of finite element analysis (FEA). The FEA model has been experimentally validated using confocal microscopy and used to improve the magnetic circuit. Then, a fluidic cell has been built and the microvalve has been demonstrated to work as a check-valve or as ON/OFF valve when being magnetically actuated. Fabricated prototypes were evaluated in a flow of N2at the flow rate of 20 sccm. The operational applied pressure was 50 mbar. The microvalve has a leaking rate in the order of 1.75 sccm at 50 mbar.