摘要
设计了一种基于多壁碳纳米管(MWNT)场发射和气体吸附的压力传感器。通过热化学气相沉积法(CVD)在合金基底上直接制备具有强附着性能的MWNT薄膜,以MWNT薄膜为场发射阴极,利用气体吸附引发的场发射电流增强效应,测量环境压力。在实验室条件下分别测试了N2和大气成分下的气体压力传感性能,结果显示,MWNT阴极材料在两种气体环境中均存在小电流场发射随真空压力升高而增长的传感效应。基于该效应,设计了一种微型实用型压力传感器。该传感器具有量程宽(1×10^-7~1×10^-3 Pa)、体积小(4 mm×5 mm×9 mm)、功耗低(5×10^-6~0.8 W)、无干扰、长寿命等优点。传感器封装在X光管中进行测试的结果表明,封装后X光管内部真空度升高可达2个数量级,且X光管的真空度随放置时间的延长而变差,结果符合理论预期。
A vacuum pressure sensor based on field emission of multi-walled carbon nanotube(MWNT)and gas absorption has been developed and investigated. The multi-walled carbon nanotube films with strong adhesion are prepared on Hastelloy alloy by thermal chemical vapor deposition method(CVD),and then the MWNT films are used as field emission cathode material in bipolar structure. Later,environmental pressure is measured by gas absorptions on the MWNT films,which results in the effect of current increasing in the process of field emission. The experiments of N2 and air’ s sensing properties show that in the condition of low-current field emission in N2 and air,the MWNT emitter demonstrates the sensing effect that low-current emission increases with increasing the vacuum pressure. According to the sensing effect,a miniature sensor has been designed. This sensor has the advantages of wide measurement range(1×10-7~1×10-3Pa),small dimension(4 mm×5 mm×9 mm),low power consumption(5×10-6~0.8 W),no interference to the device,long life,and so on.The tests of the sensor sealed in X-ray tube,show that the internal vacuum degrees of X-ray tubes are about two orders of magnitude higher than that before being sealed,and that the vacuum degrees of the X-ray tubes become lower gradually.The result agrees with the theoretical expectation.
作者
康颂
董长昆
张纯
KANG Song;DONG Changkun;ZHANG Chun(Institute of Micro-nano Structures&Optoelectronics,Wenzhou University,Wenzhou 325035,Zhejiang,China;Wenzhou CTCT Electronics Co.,Ltd.,Wenzhou 325000,Zhejiang,China)
出处
《真空与低温》
2019年第4期237-242,共6页
Vacuum and Cryogenics
基金
国家自然科学基金项目(61620106006、61871292)
关键词
多壁碳纳米管
化学气相沉积
吸附
场发射
气体压力传感
X射线管
multi-walled carbon nanotube
chemical vapor deposition
adsorption
field emission
pressure sensing
X-ray tube
