A Wearable Pressure Sensor Based on Ionogel/Textile for Human Motion Monitoring

The growth of flexible sensors has always been challenging since the sensing behavior, mechanic performance and fatigue resistance remain to be improved. In this paper, a wearable pressure sensor with fast response and high sensitivity based on ionogel/textile is fabricated. The ionogel is a double-network (DN) structure composed of polydimethylacrylamide (PDMAAm) skeleton and silica particles, carrying ionic liquids (ILs), which serves as a piezoresistive device. By impregnating and polymerization with the ionogel-prepolymer solution, a conventional cotton knitted fabric is converted into a conductive and piezoresistive composite. The fabric serves as a ductile supporting matrix for the ionogel, supplementing the piezoresistive contribution of the brittle silica network. This ionogel/textile composite has a high sensitivity ( S =86.90 kPa −1 ) and durability, continuously outputting stable electric signal during monitoring the motion states of different joints in human body. Through the impregnation-polymerization approach, the selected areas toward to the specific joints positions in clothing can be fabricated into piezoresistive devices. The incorporation of textile improves the stress loading and sensing behavior of the ionogel to work steadily under the sole of the foot for gait monitoring. This ionogel/textile device provides a potential formula of wearable sensors, stepping toward the burgeoning diversified-technologies assisted intelligence system.