B5.3 - Selectivity Improvement of High-Temperature Resonant Gas Sensors using Micromachined Membrane Arrays

Denny Richter, Jan Sauerwald & Holger Fritze
Different types of piezoelectric langasite (La3Ga5SiO14) membranes are manufactured using wet chemical etching. The membranes show thicknesses as low as 25 µm, leading to a resonance frequency of 60 MHz. Arrays of membranes are coated with platinum electrodes and different metal oxide sensor films such as CeO2 and SnO2 using pulsed laser deposition. The sensor arrays are tested at 600 °C at different oxygen partial pressures in hydrogen and carbon monoxide containing gas mixtures. In...