Chemically etched resonant LGS microsensors

Abstract

Materials like langasite (LGS), langatate (LGT) or gallium orthophosphate (GaPO4) crystals have higher piezoelectric coefficients and also have a better high-temperature behaviour than quartz crystal. Thus they are worth being considered as a replacement for quartz in applications such as oscillators, piezoelectric accelerometers, microbalances or clocks. Length-extension resonators have already been manufactured using quartz crystal in order to get atomically-resolved imaging by frequency-modulation atomic force microscopy. The goal of this study is to obtain better results with langasite. It has been shown that LGS-crystal microsensors should have a sensitivity three times better than quartz crystal ones. This fact added to the existence of temperature-compensated cuts for the extensional mode of vibration is of prime importance for applications such as microcantilevers for frequency-modulation atomic force microscopes. This paper focuses on the fabrication of Langasite resonators with different cut angles around the temperature-compensated cuts both in length-extension and flexure mode.