Polyelectrolyte-based wireless and drift-free iontronic sensors for orthodontic sensing
Jia Song, Rusong Yang, Junli Shi, Xingxing Chen, Sai Xie, Zelong Liao, Ruijie Zou, Yupeng Feng, Terry Tao Ye, Chuan Fei Guo
Abstract
The real-time monitoring of health conditions of humans is a long-lasting topic, but there are two major challenges. First, many biomedical applications accept only implanted sensors. Second, tissue-like soft sensors often suffer from viscoelasticity-induced signal drift, causing inaccurate measurements. Here, we report a wireless and drift-free sensory system enabled by a low-creep polyelectrolyte elastomer. The system consists of the iontronic pressure sensors incorporating inductance-capacitance (LC) oscillators, exhibiting combined low drift ratio, high Q factor, high robustness to interferences, and wide-range measurement, superior to other capacitive sensors using regular dielectrics or ionogels. We have recorded 14-day orthodontic loads of two subjects using the system, showing pressure decreasing from 300 to 50 kPa and torque from 12.5 to 0.5 N·mm. The wireless, drift-free sensory system may be extended to other implants for long-term and accurate sensing.