Surface Acoustic Wave Actuation Devices Based On MEMS Technology

SAW(Surface Acoustic Wave) is a kind of elastic wave thatpropagates along material surface. It can propagate on surface ofpiezoelectric material which plays as acoustic propagation medium aswell as electro-acoustic transduction material. With the development ofMicro-Electronic-Mechanical-System(MEMS), the research of SAWextends to many fields. In1990s, SAW solid actuation was realized. Theapplication of SAW on microfluidics has achieved great success in thiscentury. Versatile experiments have been realized successfully based onSAW MEMS: solid actuation, droplet actuation, micro-heating,micro-enrichment/mixing and atomization. SAW actuation devices arevery promising in the Lab-on-Chip application.This dissertation includes following parts，The significance of MEMS process technology’s application onSAW device research is illustrated. SAW device research anddevelopment at home and abroad are introduced.The principle and properties of SAW are illustrated; the choice ofmaterial and process is discussed in detail. Lift-off process is adopted tofabricate actuation device. The application of SAW in liquid atomization,micro-enrichment/mixing, droplet actuation, solid actuation is introduced.The principle of SAW liquid actuation is illustrated. Liquid actuationis realized and droplet actuation model is derived. Experiment result proves to agree with actuation model. Finally, a liquid test stagetechnology based on SAW liquid actuation is brought forward.The principle of SAW solid actuation is illustrated. A slider withmetal pillar array and a device with magnetic repulsive force as preloadforce are fabricated. Solid actuation is not realized.The principle of SAW liquid atomization is illustrated. Dropletatomization is realized with experiment device. Experiment result agreeswith theoretical derivation generally.ANSYS and MATLAB are utilized to simulate SAW actuationproperties.Finally, the development and research of SAW device in future arediscussed.