A MULTILAYER STRUCTURE FOR LOVE-MODE ACOUSTIC SENSORS

A novel multilayer structure, consisting of polymer/SiO2/ST-quartz, ha s been evaluated for Love-mode acoustic sensors. The properties of the se new devices have been compared with those of SiO2/quartz and polyme r/quartz devices. Mass sensitivity, insertion loss, temperature coeffi cient of the oscillation frequency and frequency stability are studied as a function of the layer thickness. Optimized devices exhibit highe r sensitivity than both the SiO2/quartz and the polymer/quartz devices produced here. Reduced temperature coefficient of frequency can be ob tained in the polymer/SiO2/ST-quartz devices due to a compensating eff ect of the polymer and SiO2 films. Some of the devices have been opera ted efficiently in water with good stability, which is promising for b iosensing applications. (C) 1998 Elsevier Science S.A.