IEEE Trans Ultrason Ferroelectr Freq Control. 2020 Apr;67(4):883-886. doi: 10.1109/TUFFC.2019.2956814. Epub 2019 Nov 29.
A novel quartz crystal resonator (QCR) sensor with a printed-on-crystal conductive coil, named sensor coil, is presented. The sensor coil electromagnetically coupled to an external readout coil allow to perform contactless interrogation of the QCR working as a stand-alone sensor unit. A frequency-domain readout technique is adopted that allows dual-harmonic operation by detecting the QCR frequencies of the fundamental and third harmonic, and offers first-order independence from the stand-off distance between the sensor and the readout unit. The QCR electrodes and sensor coil have been printed on a 330- [Formula: see text]-thick bare AT-cut quartz crystal exploiting the aerosol jet printing technology. The fabricated QCR sensor has reference values of the fundamental and third harmonic frequencies at 4.77 and 14.22 MHz, respectively. Distance-independent contactless operation has been demonstrated for distances up to 12 mm. The readout frequencies deviate from reference values less than 10 and 90 ppm for the fundamental and third harmonic, respectively, thus validating the proposed principle.
提出了一种新型的石英晶体谐振器（QCR）传感器，其带有印制在晶体上的导电线圈，称为传感器线圈。该传感器线圈与外部读取线圈电磁耦合，允许对作为独立传感器单元的 QCR 进行非接触式询问。采用频域读取技术，通过检测 QCR 的基频和谐波的第三频率，可以实现双谐波操作，并提供了对传感器和读取单元之间的间隔距离的一阶独立性。QCR 电极和传感器线圈已使用气溶胶喷射打印技术印制在 330-μm 厚的裸 AT 切石英晶体上。制造的 QCR 传感器的基频和谐波第三频率的参考值分别为 4.77 和 14.22 MHz。已经证明了距离可达 12mm 的非接触式、距离无关的操作。对于基本频率和谐波第三频率，读取频率的偏差小于参考值的 10 和 90ppm，从而验证了所提出的原理。
