Flexible and Transparent Surface Acoustic Wave Microsensors and Microfluidics

AbstractThis paper reports the development of flexible and transparent (FT) surface acoustic wave (SAW) technology, and FT-SAW based various sensors (temperature, humidity, UV-light and strain) and microfluidics on polymer and glass. The devices on polymers have the Rayleigh and Lamb resonances, while those on glass have the Rayleigh mode only. All the modes have large signal amplitudes. FT-SAW based sensors show excellent sensitivities, comparable to or better than those on rigid substrates. The temperature sensitivity of the sensors on PI is more than one order of magnitude larger than those on rigid substrates. The humidity sensitivity can be further increased significantly by using a graphene oxide (GO) sensing layer. All types of the sensors have excellent stability and reliability. FT-SAW also demonstrated very good capability to deliver microfluidic functions such as acoustic streaming and particle concentration etc. The results demonstrated the FT-SAW have great potential for applications