Sensors 2012, 12(6), 7157-7168; doi:10.3390/s120607157
A Sub-ppm Acetone Gas Sensor for Diabetes Detection Using 10 nm Thick Ultrathin InN FETs
1
Institute of NanoEngineering and MicroSystems, National Tsing Hua University, Hsinchu 30013, Taiwan
2
Institute of Electronics Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
3
Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
*
Author to whom correspondence should be addressed.
Received: 16 April 2012 / Revised: 15 May 2012 / Accepted: 21 May 2012 / Published: 29 May 2012
(This article belongs to the Section Chemical Sensors)
Abstract
An indium nitride (InN) gas sensor of 10 nm in thickness has achieved detection limit of 0.4 ppm acetone. The sensor has a size of 1 mm by 2.5 mm, while its sensing area is 0.25 mm by 2 mm. Detection of such a low acetone concentration in exhaled breath could enable early diagnosis of diabetes for portable physiological applications. The ultrathin InN epilayer extensively enhances sensing sensitivity due to its strong electron accumulation on roughly 5–10 nm deep layers from the surface. Platinum as catalyst can increase output current signals by 2.5-fold (94 vs. 37.5 μA) as well as reduce response time by 8.4-fold (150 vs. 1,260 s) in comparison with bare InN. More, the effect of 3% oxygen consumption due to breath inhalation and exhalation on 2.4 ppm acetone gas detection was investigated, indicating that such an acetone concentration can be analyzed in air. View Full-TextKeywords:
indium nitride (InN); acetone; gas sensor; diabetic; platinum (Pt)
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Kao, K.-W.; Hsu, M.-C.; Chang, Y.-H.; Gwo, S.; Yeh, J.A. A Sub-ppm Acetone Gas Sensor for Diabetes Detection Using 10 nm Thick Ultrathin InN FETs. Sensors 2012, 12, 7157-7168.