Strategy to minimize bending strain interference for flexible acoustic wave sensing platform

• Main Authors: Zhou, Jian, Ji, Zhangbin, Guo, Yihao, Liu, Yanghui, Zhuo, Fengling, Zheng, Yuanjin, Gu, Alex Yuandong, Fu, YongQing, Duan, Huigao
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Electrical and electronic engineering; Flexible Acoustic Wave Sensors; Bending Strain Interference
• Online Access: https://hdl.handle.net/10356/164651
• Institution: Nanyang Technological University

There are great concerns for sensing using flexible acoustic wave sensors and lab-on-a-chip, as mechanical strains will dramatically change the sensing signals (e.g., frequency) when they are bent during measurements. These strain-induced signal changes cannot be easily separated from those of real sensing signals (e.g., humidity, ultraviolet, or gas/biological molecules). Herein, we proposed a new strategy to minimize/eliminate the effects of mechanical bending strains by optimizing off-axis angles between the direction of bending deformation and propagation of acoustic waves on curved surfaces of layered piezoelectric film/flexible glass structure. This strategy has theoretically been proved by optimization of bending designs of off-axis angles and acoustically elastic effect. Proof-of-concept for humidity and ultraviolet-light sensing using flexible SAW devices with negligible interferences are achieved within a wide range of bending strains. This work provides the best solution for achieving high-performance flexible acoustic wave sensors under deformed/bending conditions.