Numerical Study of a Piezoelectric Microvalve Using Continuum Methods

Gas flow through a conical micronozzle integrated with a piezoelectric actuator has been numerically studied using continuum methods. Experimental data of air flow through a converging-diverging nozzle of throat diameter 245 mum with and without actuator at its outlet side were used for reference. The inlet pressure was kept constant at 266 Pa in all measurements. The actuator at the nozzle outlet was fabricated from poli(vinylidene fluoride) (PVDF), a piezoelectric polymer, and has a 3 mm x 6 mm rectangular shape. A voltage of +300 V DC was used to open the device, and -200 V to close it. The micronozzle with actuator is a microvalve, since the gas flow rate can be controlled by the actuator. We used Ansys/CFX software to solve the Navier Stokes equations for this valve system. The Mach number was obtained for both cases, micronozzle with and without actuator at the outlet.