Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Ontario, N2L 3G1, Canada.
Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Avenue West, Ontario, N2L 3G1, Canada.
Nano Lett. 2022 Apr 27;22(8):3196-3203. doi: 10.1021/acs.nanolett.1c04378. Epub 2022 Apr 11.
A resonant microcantilever sensor is fabricated from a zinc oxide (ZnO) thin film, which serves as both the structural and sensing layers. An open-air spatial atomic layer deposition technique is used to deposit the ZnO layer to achieve a ∼200 nm thickness, an order of magnitude lower than the thicknesses of conventional microcantilever sensors. The reduction in the number of layers, in the cantilever dimensions, and its overall lower mass lead to an ultrahigh sensitivity, demonstrated by detection of low humidity levels. A maximum sensitivity of 23649 ppm/% RH at 5.8% RH is observed, which is several orders of magnitude larger than those reported for other resonant humidity sensors. Furthermore, the ZnO cantilever sensor is self-actuated in air, an advantageous detection mode that enables simpler and lower-power-consumption sensors.
一种共振微悬臂传感器由氧化锌 (ZnO) 薄膜制成，该薄膜同时作为结构层和传感层。采用开放空气空间原子层沉积技术沉积 ZnO 层，以实现约 200nm 的厚度，比传统微悬臂传感器的厚度低一个数量级。层数、悬臂尺寸的减少以及整体质量的降低导致超高的灵敏度，可检测低湿度水平。在 5.8%RH 时，观察到最大灵敏度为 23649ppm/%RH，比其他共振湿度传感器报道的灵敏度大几个数量级。此外，氧化锌微悬臂传感器在空气中自激，这种有利的检测模式使传感器更简单、功耗更低。
