Arunachalam Shivaram, Izquierdo Ricardo, Nabki Frederic
Department of Electrical Engineering, École de Technologie Supérieure, Montreal, QC H3C 1K3, Canada.
Sensors (Basel). 2020 Mar 17;20(6):1660. doi: 10.3390/s20061660.
An ionization sensor based on suspended carbon nanotubes (CNTs) was presented. A suspended CNT beam was fabricated by a low-temperature surface micromachining process using SU8 photoresist as the sacrificial layer. Application of a bias to the CNT beam generated very high non-linear electric fields near the tips of individual CNTs sufficient to ionize target gas molecules and initiate a breakdown current. The sensing mechanism of the CNT ionization sensor was discussed. The sensor response was tested in air, nitrogen, argon, and helium ambients. Each gas demonstrated a unique breakdown signature. Further, the sensor was tested with gaseous mixtures. The sensor exhibited good long-term stability and had comparable performance to other reported CNT-based ionization sensors in literature, which use high-temperature vapor deposition methods to grow CNTs. The sensor notably allowed for lower ionization voltages due to its reduced ionization gap size.
提出了一种基于悬浮碳纳米管（CNT）的电离传感器。使用SU8光刻胶作为牺牲层，通过低温表面微加工工艺制造了悬浮的CNT梁。向CNT梁施加偏压会在单个CNT尖端附近产生非常高的非线性电场，足以使目标气体分子电离并引发击穿电流。讨论了CNT电离传感器的传感机制。在空气、氮气、氩气和氦气环境中测试了传感器的响应。每种气体都表现出独特的击穿特征。此外，还用气体混合物对传感器进行了测试。该传感器具有良好的长期稳定性，并且与文献中其他报道的基于CNT的电离传感器性能相当，后者使用高温气相沉积方法生长CNT。由于其电离间隙尺寸减小，该传感器显著允许更低的电离电压。
