College of Information science & Electronic Engineering, Zhejiang University, Hangzhou, China
Flexible Surface Acoustic Wave Devices for Transient Electronic Applications
Shuyi Huang (1,*) , Xiaozhi Wang (1) , and Jikui Luo (2,3) (1) Key Lab of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang，College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China (2) College of Electron Infor., Hangzhou Dianzi University, Hangzhou, China (3) Institution of Renewable Energy & Environment Technology, University of Bolton, Dean Road, Bolton BL35AB, United Kingdom
The development of flexible transient electronic devices is critically important for environmentally and human body friendly technologies, because the transient electronic devices can not only dissolve completely by natural water or biofluids after stable operation for a specific period of time and have no negative impact on the environment and the human body, but also have a better adaptation to some irregular surfaces in human body and natural environment. Previous works have reported several flexible transient electronic devices known as energy harvesters , supercapacitor  and medical sensor . In this work, we firstly fabricated flexible and fully degradable surface acoustic wave devices (FFDSAW), which are widely used in filters, duplexers, multi-physics parameter sensors and have great potential in wireless passive applications. FFDSAW are based on flexible and biocompatible substrate PLGA film (about 20 μm) and piezoelectric material ZnO (about 3 μm) film, biocompatible tungsten electrode (about 250 nm) is used as the interdigital electrode. The results indicate that FFDSAW devices can work as flexible temperature sensor and humidity sensor. The TCF of flexible temperature sensors is about 8.5 ppm/K, and a high sensitivity of 47.8 kHz/10% RH has been obtained from FFDSAW sensors with no surface treatment. When devices were degraded in PBS solution (PH 7.2, 37 °C), the resonant frequency of the device remained unchanged, the insertion loss gradually increased, and finally the performance of SAW devices disappeared in about 8 hours, and the entire device degraded completely in about 27 hours. In conclusion, a flexible and environmentally and human body friendly surface acoustic wave device is firstly fabricated in this work and it can work as flexible temperature sensors and flexible humidity sensors with high sensitivity, and it also have great potential for wearable applications for flexible and biocompatible materials selection.
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A Ph.D student from College of Information science & Electronic Engineering of Zhejiang University. Research topics include flexible electronics and transient electronics and their applications.
Zhejiang University (ZJU) is one of China’s top higher education institutions, as well as one of its oldest, it is located in Hangzhou, Zhejiang provence, China.