基于碳纳米材料的柔性薄膜器件研究

Flexible devices based on carbon nanotubes

近年来,可穿戴或贴合式的传感器在实时生理监测、特殊环境信号检测等领域的需求日益凸显,柔性传感器成为当前研究的热点.碳纳米管(CNT),由于其独特的电学和力学性能,在新型电子器件的发展中扮演着越来越重要的角色.本文介绍了几类典型的基于碳纳米管的柔性红外传感器和微压力传感器.在柔性红外传感器的研制中,利用碳纳米管与SiO_2的界面以及不同掺杂的CNT形成的p-n结,设计和制备了两种不同类型的高灵敏度柔性红外传感器,实验结果证明界面载流子行为对传感器的响应速度有重要的影响.另一方面,利用碳纳米管的优秀导电性,设计和制备了两种力传感器.通过银纳米颗粒修饰的碳纳米管制备的柔性拉力传感器,兼具高拉伸度和高灵敏度,具有优秀的应变系数.此外,利用碳纳米管和三棱锥的微结构制备了响应灵敏的微压力传感器,具有优秀的响应幅度与响应速度.

In recent years, with the increasing application of wearable devices and skin-electronics in the area of physiological and environmental monitoring, flexible sensors are becoming one of the most popular research subjects. Since the discovery of carbon nanotubes（CNTs）, the research effort on one-dimensional（1D） materials has rapidly increased, driven by their extraordinary electrical and mechanical properties. Owing to its unique electrical and mechanical properties, carbon nanotubes（CNTs） play an important role in developing of novel devices, such as field of electrodes, transistors and nano sensors. Besides, the sp2 orbital hybridization of CNTs contributes to the stable physical and electrical properties even under the bending condition, which makes them an ideal candidate in the use of flexible devices. This paper will introduce some kinds of typical CNT-based, flexible infrared detectors and force sensors. Two kinds of CNT-based, flexible infrared detectors have been fabricated. One is based on the CNT p-n junction and the other is based on the interface between CNTs and SiO_2. It is found that the interface between CNTs and SiO_2 is proved to greatly enhance the IR response speed. Detector which kept the layer of SiO_2 had a shorter response time（40 ms） than the one which have not（800–1200 ms）. Besides, two kinds of force sensors have been fabricated. One is the flexible tension sensor, which bases on the silver nanoparticle modified CNTs and shows excellent tensibility and sensitivity. The results indicate that with the increase of the silver concentration, the strain sensor tends to present better tensibility and recuperability. The other force sensor is the micro-pressure sensor, which bases on designed microstructures and the CNT conductivity layer. This kind of sensor shows fast response speed and high sensitivity.