Noncontact excitation of quartz crystal resonator chips

Abstract

The use of an acoustic wave device as a chemical sensing element is often limited by contact with wires and supports and by the need to control its fluidic environment. This letter describes the validation of a versatile noncontact configuration that makes use of a spiral coil antenna to electromagnetically excite miniature piezoelectric chips. Experimental evidence is provided to demonstrate that an AT cut quartz crystal resonator can be cleaved into chips that can be excited electromagnetically via coupling to the electric Y axis of the crystal. An unpredicted result was the superior coherence of chips at frequencies determined by their local thickness.