Highly Sensitive and Stretchable Strain Sensor Based on Ag@CNTs.

Qiang Zhang,Wendong Zhang,Jianlong Ji,Aoqun Jian,Qianqian Duan,Lihua Liu,Dong Zhao,Shengbo Sang

doi:10.3390/nano7120424

Abstract

Due to the rapid development and superb performance of electronic skin, we propose a highly sensitive and stretchable temperature and strain sensor. Silver nanoparticles coated carbon nanowires (Ag@CNT) nanomaterials with different Ag concentrations were synthesized. After the morphology and components of the nanomaterials were demonstrated, the sensors composed of Polydimethylsiloxane (PDMS) and CNTs or Ag@CNTs were prepared via a simple template method. Then, the electronic properties and piezoresistive effects of the sensors were tested. Characterization results present excellent performance of the sensors for the highest gauge factor (GF) of the linear region between 0–17.3% of the sensor with Ag@CNTs1 was 137.6, the sensor with Ag@CNTs2 under the strain in the range of 0–54.8% exhibiting a perfect linearity and the GF of the sensor with Ag@CNTs2 was 14.9.

Highlights

Stretchable, skin-mountable, and wearable strain sensors are required for several potential applications including personalized health-monitoring, human motion detection, human-machine interfaces, soft robotics, and other applications [1,2,3,4,5,6,7,8,9]
Significant efforts have been invested to develop highly sensitive and stretchable strain sensors, which should be both compliant and sensitive enough to detect the process of body motions and work at high strain to monitor large-scale deformations [10,11,12,13]
The introduction of conductive nanomaterials to stretchable strain sensors that are based on PDMS is a popular means in these studies to improve the sensitivity and stretchability of sensors [6,7,8,9,10]

Summary

Introduction

Stretchable, skin-mountable, and wearable strain sensors are required for several potential applications including personalized health-monitoring, human motion detection, human-machine interfaces, soft robotics, and other applications [1,2,3,4,5,6,7,8,9]. Based on the good performances of Ag nanomaterials and CNTs, some researchers mixed these two materials physically together to improve the properties of the PDMS based soft strain sensors [25,26]. Ag@CNT nanocomposites were designed in chemical method owning to better combining the advantages of both Ag nanoparticles and CNTs to improve the properties of the as-prepared sensor. The Ag nanoparticles were coated closely around CNTs via reduction reaction reported in this work, so the two nanomaterials were always combined together during stretching. The Ag@CNT nanocomposites show the advantages of these two nanomaterials all the time, and they better improve the properties of the as-prepared sensor. The Ag@CNT-based sensors show high sensitivity and good linearity, and were applied to body movement

Experimental Section

Preparation of Sensors

Conclusions