Highly Sensitive Hot-Wire Anemometry Based on Macro-Sized Double-Walled Carbon Nanotube Strands

Dingqu Wang; Wei Xiong; Zhaoying Zhou; Rong Zhu; Xing Yang; Weihua Li; Yueyuan Jiang; Yajun Zhang

doi:10.3390/s17081756

Highly Sensitive Hot-Wire Anemometry Based on Macro-Sized Double-Walled Carbon Nanotube Strands

Sensors (Basel). 2017 Aug 1;17(8):1756. doi: 10.3390/s17081756.

Authors

Dingqu Wang^{1

2

3}, Wei Xiong⁴, Zhaoying Zhou⁵, Rong Zhu⁶, Xing Yang⁷, Weihua Li⁸, Yueyuan Jiang⁹, Yajun Zhang¹⁰

Affiliations

¹ Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China. wangdq@tsinghua.edu.cn.
² Collaborative Innovation Center of Advanced Nuclear Energy Technology, Tsinghua University, Beijing 100084, China. wangdq@tsinghua.edu.cn.
³ Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education of China, Tsinghua University, Beijing 100084, China. wangdq@tsinghua.edu.cn.
⁴ Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China. xwthu@tsinghua.edu.cn.
⁵ State Key Laboratory of Precision Measurement Technology and Instrument, Department of Precision Instrument, Tsinghua University, Beijing 100084, China. zhouzz@tsinghua.edu.cn.
⁶ State Key Laboratory of Precision Measurement Technology and Instrument, Department of Precision Instrument, Tsinghua University, Beijing 100084, China. zr_gloria@mail.tsinghua.edu.cn.
⁷ State Key Laboratory of Precision Measurement Technology and Instrument, Department of Precision Instrument, Tsinghua University, Beijing 100084, China. yangxing@tsinghua.edu.cn.
⁸ Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China. liweihua@tsinghua.edu.cn.
⁹ Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China. jiangyy@tsinghua.edu.cn.
¹⁰ Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China. yajun61@tsinghua.edu.cn.

Abstract

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.

Keywords: carbon nanotube; flow-rate sensor; highly sensitive; hot-wire anemometer.