Preparation And Wearable Application Of Flexible Pressure Sensor Based On Flexible Textile

Pressure sensors are deemed as a critical sensing components in wearable devices,and various polymer assembly with different structures are selected as flexible sensor substances.The flexible substrate is of vital importance for it houses the active substance to sustain the pressure.For the pressure sensor,flexibility,resilience,compressibility and durability are key factors affecting the sensing performance.Textile materials are widely used due to their good flexibility,elasticity,high skin affinity and multi-dimensional and multi-scale characteristics.Therefore,we adopted the 3D non-woven fabric and silver-coated fabric/PP fiber assembly as the flexible substrates,and then study the effects of them on sensing performances and wearable applications.The mainly research contents are as follows:1.We developed a resistance pressure sensor with rGO incorporated into a 3D polyester non-woven fabric via simple dip-coating method,and the conductivity of this pressure sensor is 0.29 S/m.We then proposed a mechanical model to analyse the structural parameters?fiber diameter,fiber volume fraction?.And tested the excellent sensing performances of this sensor:high sensitivities(23.41 kPa^-1under conmpressing,and 35.37kPa^-1under bending),short reponse time?120 ms?and recovery time?240 ms?,low resolution?18 Pa under compressing,and 21Pa under bending?,and ultra low hysteresis?0.8%??2.Inspired by conventional pillow,we fabricated the pillow-shaped 3D hierarchial pressure sensors based on silver-coated fabric and PP fiber assembly via thermal bonding technology.This pressure sensor is of outstanding sensing performances because of the instinct knitted structure and good resilience of fiber assembly,such as high sensitivity(3.504 kPa^-1)and excellent repeatability?2%after 4,500 cycles?.Besides,the sensing mechanism was further illustrated.3.The above two kinds of flexible sensors based on textile structures were connected to human body and other textiles to detect various physiological activities of human body,such as joint bending,foot pressure,vocal cord vibration,breathing,pulse and sleeping postures.In addition,we also performed multipoint continuous monitoring of sleep postures.Therefore,our proposed flexible resistance pressure sensors based on textile structures provided a new approach in monitoring the breath states of any age groups,including children and the elderly,to ensure their health status.