Wang Dingqu, Xiong Wei, Zhou Zhaoying, Zhu Rong, Yang Xing, Li Weihua, Jiang Yueyuan, Zhang Yajun
Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China.
Collaborative Innovation Center of Advanced Nuclear Energy Technology, Tsinghua University, Beijing 100084, China.
Sensors (Basel). 2017 Aug 1;17(8):1756. doi: 10.3390/s17081756.
This paper presents a highly sensitive flow-rate sensor with carbon nanotubes (CNTs) as sensing elements. The sensor uses micro-size centimeters long double-walled CNT (DWCNT) strands as hot-wires to sense fluid velocity. In the theoretical analysis, the sensitivity of the sensor is demonstrated to be positively related to the ratio of its surface. We assemble the flow sensor by suspending the DWCNT strand directly on two tungsten prongs and dripping a small amount of silver glue onto each contact between the DWCNT and the prongs. The DWCNT exhibits a positive TCR of 1980 ppm/K. The self-heating effect on the DWCNT was observed while constant current was applied between the two prongs. This sensor can evidently respond to flow rate, and requires only several milliwatts to operate. We have, thus far, demonstrated that the CNT-based flow sensor has better sensitivity than the Pt-coated DWCNT sensor.
本文介绍了一种以碳纳米管（CNT）作为传感元件的高灵敏度流量传感器。该传感器使用微米尺寸、厘米长的双壁碳纳米管（DWCNT）束作为热线来感测流体速度。在理论分析中，该传感器的灵敏度被证明与它的表面积比呈正相关。我们通过将DWCNT束直接悬浮在两个钨电极上，并在DWCNT与电极之间的每个接触点滴上少量银胶来组装流量传感器。DWCNT的电阻温度系数（TCR）为1980 ppm/K，呈正相关。当在两个电极之间施加恒定电流时，观察到DWCNT上的自热效应。该传感器对流速有明显响应，运行仅需几毫瓦。到目前为止，我们已经证明基于碳纳米管的流量传感器比镀铂的DWCNT传感器具有更好的灵敏度。
