A Principle to Generate Flow for Thermal Convective Base Sensors

This paper presents a thin millimeter-scaled device that can generate a closed flow within itself with a velocity of the order of a few m/s. The device comprises a piezoelectric pump with a PZT membrane, housing chamber, and a closed network channel connected to the housing chamber through a specific throat. We investigate the device by computational fluid dynamics. This device is used to produce several free jet flows depending on the structure of the network channel. In this study, four jet flows comprising two perpendicular pairs of flows are demonstrated. If the PZT membrane vibrates within a suitable range, the self-similarity of the axial velocity (along the jet direction) to the cross distances scaled by the half-widths of the jet is observed for a certain range of axial distance. Each jet flow can bend almost freely in three dimensions. The two remaining flow components are small as compared to the axial component. The device potentially has wide applications in flow-based sensors.