New Manipulator Based on Surface Acoustic Wave Streaming

Abstract

We report a new micromanipulator based on the surface acoustic wave (SAW) streaming. When a small solid object is loaded onto a water droplet placed on a SAW substrate and the SAW is excited, the object can be moved easily and smoothly with the droplet in the SAW propagation direction. Small steel balls of 0.5 to 4.0 mm in diameter were examined as manipulated samples to be loaded onto a droplet. The experimental results are compared with those of the direct drive method without preloading, by which an object is moved towards an operating interdigital transducer (IDT) in the direction opposite to the SAW propagation direction. It was observed, that the driving efficiency of the present method was sixty times larger than that of the direct drive method. Moreover, a teflon sheet, which is difficult to move by the direct drive method, can be moved with ease by the present method. We conclude that the present method has a high potential for practical use as a micromanipulator.