Hydrodynamic Focusing Micropump Module with Pdms/nickel-particle Composite Diaphragms for Microfluidic Systems

As part of the Post-Katrina project, a multi-fluidic speed-modulating (MFSM) micropump module combined with Tesla valves and hydrodynamic focusing micro-fluidic channels was designed, fabricated, and tested to help regulating sample flow across the nanowire-seeded sensor areas embedded in microfluidic channels. The size of the entire module is 33 mm x 25 mm x 8mm and comprises of three MFSM micropumps. The pumps are simultaneously operated by the same actuation source. Each micropump consists of Tesla-type valves in the bottom layer and PDMS/Ni-particle composite (PNPC) diaphragm in the middle layer. The deflection of the diaphragm is obtained by an external pneumatic force, and a permanent magnet controls the membrane displacement resulting from interaction of magnetic field and PNPC diaphragm. Analyses of the magnetic modulation force, flow rate of the MFSM micropump, and the hydrodynamic focusing were demonstrated.