A new microvalve controlled by surface acoustic wave.

A new microvalve controlled by surface acoustic wave was presented. A shape memory alloy (SMA) with plastic sheet was integrated into a printed circuit board by way of small copper pipe. A 128°-YX LiNbO3piezoelectric substrate was under the SMA wire with small gap. A polydimethylsiloxane (PDMS) microchannel was squeezed by the extension of the heated SMA wire due to surface acoustic wave radiation. The microvalve state was then changed. Experimental results show that the switching-off time of the microvalve is 39.533 s at 28.5 dBm electric signal power. The variation of SMA size during expansion is theoretically calculated. [ABSTRACT FROM PUBLISHER]