Highly sensitive cantilever type chemo-mechanical hydrogen sensor based on contact resistance of self-adjusted carbon nanotube arrays

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• 作者：Min-Ook KimAuthor Vitae ; Kyounghoon LeeAuthor Vitae ; Hyungjoo NaAuthor Vitae ; Dae-Sung KwonAuthor Vitae ; Jungwook ChoiAuthor Vitae ; Jae-Ik LeeAuthor Vitae ; Dae-Hyun BaekAuthor Vitae ; Jongbaeg Kim ; ^{kimjb@yonsei.ac.kr" class="auth_mail}Author Vitae
• 关键词：Chemo-mechanical ; Hydrogen sensor ; Cantilever ; Carbon nanotube arrays ; Highly sensitive ; Low minimum detection limit
• 刊名：Sensors and Actuators B: Chemical
• 出版年：5 July, 2014
• 年：2014
• 卷：197
• 期：Complete
• 页码：414-421
• 全文大小：2786 K

文摘

A highly sensitive cantilever type chemo-mechanical hydrogen sensor with a novel sensing mechanism that can detect changes in contact resistance in self-adjusted carbon nanotube (CNT) arrays is described. The fabricated sensor is fully batch-fabricated on a silicon-on-insulator (SOI) wafer and is composed of two facing sets of CNT arrays, situated between a Pd-coated micro-cantilever, that serve as the electrode and counter-electrode. When the sensor is exposed to various concentrations of hydrogen at room temperature, resistance is decreased as the cantilever deforms and increases inter-CNT contact. Turning off the hydrogen re-shrinks the Pd, restoring the original cantilever position and recovering the initial resistance. The sensor can detect hydrogen diluted in nitrogen at concentrations of up to 4% and has an average response as high as 鈭?.22% to a 0.1% concentration of hydrogen in air, which is the minimum detection limit. This sensitivity, which is much higher than in previously reported cantilever-type resistive chemo-mechanical hydrogen sensors, can be attributed to the novel sensing mechanism in which the narrow-gap between CNT arrays comprise the sensing component.