A Masterpiece of Superior Crystals: Quartz Resonant Pressure Sensor—A Review

Quartz resonant pressure sensors have emerged as a promising technology for precise pressure measurements in a variety of applications such as aerospace, meteorological observation, and energy exploitation. These sensors are inherently compatible with digital techniques and provide high accuracy, high resolution, and good long-term stability over a wide pressure range. These excellent features can be tentatively attributed to the mechanical and electrical properties of quartz crystals. However, there are no reviews that delve into the mechanisms underlying the superior performance of such sensors, leading to a bottleneck in technological development. Accordingly, this article reviews the key physical properties and effects of crystalline material, which have driven sensor technology advances. In particular, it is gathered that crystal cuts significantly influence the operation and performance of the sensors. These cuts can be classified into three categories based on the sensitivity to the measurement: pressure-sensitive, temperature-sensitive, and frequency-reference cuts. We also summarize the mechanisms that govern the optimization of the crystal cuts and the effect of the combinations of different cuts on performance improvement. In addition, the unique physical effects of quartz crystals are presented, and their role in sensor technology innovation is discussed in detail. Next, the different quartz resonant pressure-sensing technologies available are classified according to the acoustic wave transmission method: surface acoustic wave, vibrating beam, and vibrating diaphragm types. We conclude this article with an analysis of state-of-the-art sensor technologies and a discussion on the status of the sensor industry and the latest technology trends.