Analysis of the electro-elastic properties of custom quartz tuning forks for optoacoustic gas sensing

• Published in: Sensors and actuators. B, Chemical Vol. 227; pp. 539 - 546
• Main Authors: Patimisco, P., Sampaolo, A., Dong, L., Giglio, M., Scamarcio, G., Tittel, F.K., Spagnolo, V.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2016
• Subjects: Actuators; Contact; Crystals; Electrical conductance; Electrical resistance; Gas sensing; Physical properties; Quality factor; Quartz; Quartz Enhanced Photoacoustic Spectroscopy; Quartz tuning fork; Resonance frequency; Tradeoffs; Tuning; Electrical conductance; Quartz Enhanced Photoacoustic Spectroscopy; Quartz tuning fork; Gas sensing; Quality factor; Resonance frequency
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2015.12.096

•We designed and realized a set of four custom tuning forks.•We investigated the Quartz tuning forks (QTFs) electrical performance.•We determined the dependence of QTFs main physical parameters on their dimensions.•We identified in quality factor and conductance the figures of merit for sensing.•We provided guidelines to design tuning forks for photoacoustic spectroscopy. We report a detailed experimental and theoretical analysis of the influence of quartz tuning fork (QTF) dimensions on the main physical parameters controlling the QTF performance, namely, the quality factor Q, the resonance frequency, the fork stiffness, the spring constant, and the electrical resistance. Two different gold contact patterns were also compared. As a general trend, the QTF performance in terms of Q and electrical conductance values improves at increasing both the crystal thickness T and prong thickness w, while decreasing the prongs length Lp. However, since the QTF resonance frequency f0 is proportional to T/Lp2, a trade-off should be found in order to keep f0<40kHz, i.e., well below the typical values of non-radiative relaxation rate of a targeted gas absorption lines.