Piezoresistive Sensor With High Elasticity Based On 3D Hybrid Network Of Sponge@CNTs@Ag NPs

Pressure sensors with high elasticity are in great demand for the realization of intelligent sensing,but there is a challenge to develop a simple,inexpensive,and scalable method for the manufacture of the sensors.To solve these problems,we reported an efficient and simple“dipping and coating”process to manufacture a flexible,wearable and high sensitive piezoresistive sensor,based on homogeneous 3D hybrid network of carbon nanotubes@silver nanoparticles（CNTs@Ag NPs）anchored on a skeleton sponge.The main research contents and innovations of this paper are as follows:（1）The substrate sponge with flexible,compressive,high elasticity and hydrophilic characteristic is an ideal choice as substrate of a pressure sensor.It also successfully expanded the pressure test range of the piezoresistive sensor（with a range from 2.24 to61.81 kPa）.Besides,the sponge possesses the hierarchical macroporous nature,and provides a good skeleton for the attachments of CNTs/Ag NPs.（2）In this paper,we make use of the synergy effect of CNTs@Ag NPs for compensating the demerits of each material while maintaining their merits.The preparation of the piezoresistive sensor has high sensitivity(2.12 kPa^-1at 2.24-11 kPa and about 9.08 kPa^-1at 11-61.81 kPa).We further explored the relationship between CNTs to Ag NPs’ratio（1:0,1:10,1:15,and1:20）in CNTs@Ag NPs solution and the sensor’s performance.（3）In well dispersed CNTs@Ag NPs solution,we used an efficient,low-cost‘‘dip and dry’’way to fabricate a piezoresistive sensor based on the substrate sponge and the sensing materials（CNTs@Ag NPs）,with simple structure and low cost.Our sensor was also tested for over 2000 compression-release cycles,exhibiting excellent cycling stability and almost negligible hysteresis.The outstanding performance laid a foundation for realizing flexible,wearable,high sensitive piezoresistive sensor.Sensors with high performance and a simple fabrication process are promising devices for commercial production in various electronic devices,for example,sport performance monitoring and man-machine interfaces.