Details

Autor(en) / Beteiligte

• Pang, Jintao
• Le, Xianhao
• Pang, Kai
• Xu, Zhen
• Gao, Chao
• Xie, Jin

Titel

Modified Coefficient of Equivalent Mass to Explain Decreased Relative Sensitivity of Piezoelectric Cantilever Humidity Sensor in High Mode

Ist Teil von

• Journal of microelectromechanical systems, 2020-08, Vol.29 (4), p.452-454

Ort / Verlag

New York: IEEE

Erscheinungsjahr

2020

Quelle

IEEE Xplore

Beschreibungen/Notizen

• Piezoelectric cantilevers promise broad prospects for gas sensing and biosensing due to the high sensitivity and fast response. The strong correlation between the resonant frequency and sensitivity leads to numerous cantilever-based sensors using the high-order flexural mode to realize higher absolute sensitivity. However, experiment results show that the relative sensitivity of the sensors decreases with the increase of the mode order. Herein, we explain the relative sensitivity degeneration of normal cantilevers with a modified coefficient of equivalent mass, and propose a cantilever-based humidity sensor using high-frequency mode driven by interdigital electrodes (IDEs) to enhance the relative sensitivity. Compared with the high-order mode excited by normal configuration (70.4 MHz), the high-frequency mode driven by IDEs (77.3 MHz) demonstrates an improved sensitivity around 39.2 Hz<inline-formula> <tex-math notation="LaTeX">\cdot </tex-math></inline-formula>cm 2 /ng (1.68x) at 10%-90% relative humidity. The sensitivity enhancement by IDEs is consistent with the result calculated by the modified coefficient. [2020-0055]