Floer Cecile, Elmazria Omar, Naumenko Natalya, Bartoli Florian, Ghanbaja Jaafar, Aubert Thierry, Hage-Ali Sami
IEEE Trans Ultrason Ferroelectr Freq Control. 2021 Jun;68(6):2315-2318. doi: 10.1109/TUFFC.2021.3057269. Epub 2021 May 25.
Batteryless, wireless, and packageless acoustic wave sensors are particularly desirable for harsh high-temperature environments. In this letter, an acoustic wave sensor based on a lithium niobate (Y + 128° cut, abbreviated LN-Y128) substrate with a buried platinum interdigital transducer (IDT) in an aluminum nitride (AlN) overlayer is investigated. Previously, it was demonstrated theoretically that due to the specific properties of LN-Y128, Rayleigh-type guided waves can propagate at the AlN/IDT(Pt)/LN-Y128 interface. Here, this structure is, for the first time, studied experimentally, including the growth and properties of the AlN layer onto irregular platinum IDTs. Both Shear Horizontal and Rayleigh-type waves have been identified after the AlN deposition and the velocities are consistent with the fitted SDA-FEM-SDA (a combination of finite element modeling with spectral domain analysis) simulations. Electrical measurements with a surface perturbation and temperature measurements show that the AlN/IDT(Pt)/LN-Y128 bilayer structure is promising as a packageless high-temperature sensor.
无电池、无线且无封装的声波传感器在恶劣的高温环境中尤为适用。在本信函中，研究了一种基于铌酸锂（Y + 128°切割，简称LN - Y128）衬底的声波传感器，该衬底在氮化铝（AlN）覆盖层中埋设有铂叉指换能器（IDT）。此前，从理论上证明，由于LN - Y128的特殊性质，瑞利型导波可在AlN/IDT(Pt)/LN - Y128界面传播。在此，首次对这种结构进行了实验研究，包括在不规则铂IDT上生长AlN层及其性质。在沉积AlN后，识别出了水平剪切波和瑞利型波，其速度与拟合的SDA - FEM - SDA（有限元建模与谱域分析相结合）模拟结果一致。通过表面扰动进行的电学测量和温度测量表明，AlN/IDT(Pt)/LN - Y128双层结构有望成为一种无封装的高温传感器。
