NEW MANIPULATOR BASED ON SURFACE-ACOUSTIC-WAVE STREAMING

We report a new micromanipulator based on the surface acoustic wave (S AW) streaming. When a small solid object is loaded onto a water drople t 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 dire ction. 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 res ults are compared with those of the direct drive method without preloa ding, by which an object is moved towards an operating interdigital tr ansducer (IDT) in the direction opposite to the SAW propagation direct ion. It was observed, that the driving efficiency of the present metho d was sixty times larger than that of the direct drive method. Moreove r, a teflon sheet, which is difficult to move by the direct drive meth od, can be moved with ease by the present method. We conclude that the present method has a high potential for practical use as a micromanip ulator.