A flexible sensor based on ionogel/knitted coil prepared by a simple method for accurate monitoring of human physiological signals

Flexible sensors have received increasing attention due to their various applications in health monitoring, artificial intelligence, and other fields. The simple fabrication of flexible sensing devices with high performances has been a research hotpot. In this work, an ionogel composite sensor combined with elastic knitted coil (EIC) is proposed as a wearable device to monitor human movement and related feature information. This sensor can be fabricated in a simple and easy protocol, which can work as a clothing accessary to track the wellness status parameters in daily life. After washing, the redundant gel originally embedded between the fibers was removed, improving the sensitivity of the sensor, which can provide accurate information about human joint movements and other physiological activities. The EIC sensor is in high sensitivity with superior working durability, which can provide continuous piezoresistive signals in detection mode. Other than the common joint bending movements (wrist, knee, elbow and finger) of human body, this sensor can also accurately output monitoring data on periocular, oral, and pharyngeal movements, providing information about human health status. Besides, a Morse codes transmission system can be constructed based on the piezoresistive outputs of this EIC sensor under different tapping modes, providing a new working platform in other related applications.