Abstract
Resonant cantilever based on piezoelectric materials is one of the most promising platforms for real-time humidity sensing. In this letter, we propose a humidity sensor based on an AlN piezoelectric microcantilever with a high-order resonant mode and a sensing layer of MoS2. The top electrode of cantilever is designed into two groups of segmented electrodes in order to achieve a high intensity of the resonance peak of the cantilever resonator operated at a high-order mode. Compared with the humidity sensor based on a standard cantilever with the same dimension, the sensitivity of the newly proposed humidity sensor is increased from 5.99 to 778 Hz/%RH when the humidity is about 80%RH. The resolution is increased from 0.21%RH to 0.025%RH because of the improvement of the ratio of sensitivity to noise, which cannot be achieved simply by increasing the frequency. The sensor shows a low hysteresis (5.8%) in a wide humidity sensing range from 10%RH to 90%RH. Moreover, the proposed humidity sensor has good short-term repeatability, fast response (0.6 s) and recovery (8 s) to humidity changes, indicating its great potential for fast-response detection.
Original language | English |
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Pages (from-to) | 923-926 |
Number of pages | 4 |
Journal | IEEE Electron Device Letters |
Volume | 42 |
Issue number | 6 |
Early online date | 16 Apr 2021 |
DOIs | |
Publication status | Published - Jun 2021 |
Keywords
- AlN piezoelectric cantilever
- high resolution
- humidity sensor
- MoS2
- Electrodes
- Sensitivity
- Resonant frequency
- Humidity
- Sensors
- III-V semiconductor materials
- Aluminum nitride
- Electrical and Electronic Engineering
- Electronic, Optical and Magnetic Materials