Search

A new AlN film-based surface acoustic wave (SAW) device was explored for sensing strain at high temperature. AlN/metal/Si multilayer composite structure was proposed to construct the strain sensing chip, and the corresponding theoretical analysis on SAW propagation were performed by using finite element method (FEM). High-quality AlN piezoelectric thin-film was prepared by using magnetron sputtering on Si substrate, and Pt electrodes was then lithographically prepared to build the sensing chips with one-port resonator pattern operating at 607 MHz and 620 MHz. To compensate the temperature cross sensitivity and enhance the strain sensitivity, two sensing chips were positioned perpendicular on a ceramic package, then the differential frequency signal was extracted to evaluate the applied strain. A high-temperature strain testing platform was constructed to characterize the prepared strain sensor with orthometric structure, larger strain sensitivity of 0.84 ppm/ μ ε at 550 °C in the range 0 – 500 μ ε and excellent temperature stability of 0.624 ppm/°C at the temperature range of 20–600 °C were achieved successfully. [Display omitted] • High-quality AlN piezoelectric thin films and high-temperature electrodes prepared. • Orthometric dual-resonator SAW chip based on AlN/metal/Si multilayer structure proposed. • larger strain sensitivity of 0.84 ppm/ μ ε at 550 °C in the range 0 – 500 μ ε and excellent temperature stability of 0.624 ppm/°C at the temperature range of 20 – 600 °C were achieved successfully. [ABSTRACT FROM AUTHOR]

• A Y-cut 35o X quartz with perfect temperature stability was employed as the piezoelectric substrate of the sensing device patterned by one-port resonator. • Optimization towards SAW sensing device allowing larger Q-value was conducted by using COM model. • A wireless and passive SAW strain sensor with high sensitivity and excellent temperature stability was developed at operation frequency of 434MHz. A temperature-compensated surface acoustic wave (SAW) device was developed to build a wireless and passive strain sensor. Y-cut 35° X quartz with perfect temperature stability was employed as the piezoelectric substrate of the sensing device patterned by one-port resonator. Optimization by coupling of modes (COM) model towards sensing chip was conducted to determine the optimal design parameters, which offers lager Q-value. The prepared sensing device by standard photolithographic technique operating at 434MHz was characterized wirelessly. High strain sensitivity, excellent temperature stability, and high resolution were achieved in the wireless measurements. [ABSTRACT FROM AUTHOR]