Electroactive polymer based microfluidic pump

A planar, valveless, microfluidic pump using electrostrictive poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] based polymer as the actuator material is presented. P(VDF-TrFE) thick films having a large electrostrictive strain ∼5–7% and high elastic energy density of 1 J/cm3 have been used in a unimorph diaphragm actuator configuration. The microfluidic pump was realized by integrating a nozzle/diffuser type fluidic mechanical-diode structure with the polymer microactuator. The P(VDF-TrFE) unimorph diaphragm actuator, 80 μm thick and 2.2 mm × 2.2 mm in lateral dimensions, showed an actuation deflection of 80 μm for an applied electric field of 90 MV/m. The microfluidic pump could pump methanol at a flow rate of 25 μl/min at 63 Hz with a backpressure of 350 Pa. The flow rate of this pump could be easily controlled by external electrical field. Two different sizes of nozzle/diffuser elements were studied and the pumping efficiency of these structures is 11 and 16%, respectively.