Self-healable and Stretchable Sensors for Human Motion Monitoring

Abstract

In the era of bioelectronics, wearable health monitoring devices which are flexible, skin conforming, durable, highly sensitive which can provide real-time monitoring have become a prime focus in modern health care. They have proved to be highly useful in cases of patients going through rehabilitation process, in evaluation of post-surgery performance of athletes, translation of sign language for individuals with inability to hear or early diagnosis and prognosis of certain illnesses such as Parkinson disease. They can also be widely applied in sports performance and human-machine interfaces for robotics. Flexible wearable sensors are the key point for monitoring motion and physiological signals and daily activity. The current studies on flexible and stretchable strain sensors have hardly succeeded to cover the important characteristics of the next generation of wearable electronics for rehabilitations. These features involve low cost, high sensitivity, high elasticity, self-healing capability and multi-functionality. Personalized cheap and accurate wearable electronics for human motion monitoring can help patients and doctors for rehabilitation. Here a sensitive, self-healable, and elastic strain sensor is developed by embedding nanomaterials along with a conductive polymer, PEDOT PSS. The sensors are sensitive to strain, pressure, and temperature and can achieve high stretchability up to 600% and great durability due to the self-healing properties. The electrical properties, sensitivity, and mechanical properties of the materials were tested at different strains. The conductivity of the materials goes up to 10^-3 S/cm while showing sensitivity to different temperatures between 15C to 60C based on the mechanical test. It can heal itself more than 95% in less than 3mins. Sensitivity to pressure was measured too and it shows significant changes in conductivity when a wide range of pressures from 1KPa to 1MPa was applied to the sensor.