Liquid damping isolation on quartz crystal microbalance for effective preservation of high quality factor and sensitivity in liquid

This paper reports a novel design of a quartz crystal microbalance (QCM) for effective preservation of high quality factor and sensitivity in liquid. Many previous attempts have not achieved effective solutions to improve the QCM´s performance in liquid. It is challenging to create a device without serious liquid damping effect. Our new design removes this dependence through an acoustic loss isolation layer (vacuum) and a sensing diaphragm, which reduce direct contact area at the interface between the QCM and liquid. The sensing diaphragm plays another important role of keeping the liquid damping effect at a much lower frequency than the operating frequency of the QCM. By successful isolation of the liquid damping effect from the QCM´s resonance, we have successfully been able to preserve high Q in liquid. Q of 1603 in air and 1600 in water (less than 1% reduction) have been clearly observed.