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Capacitive humidity sensors based on a newly designed interdigitated electrode structure

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Abstract

This paper presents a study of capacitive humidity sensors constructed based on a newly designed interdigitated electrode (IDE) structure with a polyimide (PI) sensing layer fabricated using micro-electro-mechanical system (MEMS) technology. The humidity sensors use an IDE with increased height, formed by the surface micromachining of a silicon substrate. The fabricated sensors showed higher sensitivity in variable ambient relative humidity (RH) when compared with the humidity sensors of a conventional IDE since the horizontal electric field lines, generated between the thick electrodes, are confined to the PI sensing layer. The effect of the thickness of the PI layer was also investigated. The fabricated sensors with a 4-μm-thick PI layer showed a higher sensitivity of 37.1 fF/%RH when compared with those of a 2- and 3-μm-thick PI layers, indicating that the properties of the sensors depend on the thickness of the PI layer. This is because the amount of the fringing electric field lines passing through the PI is determined by the PI thickness. In addition, the sensor with the 4-μm-thick PI showed very slight hysteresis with a maximum of 2.87%RH and displayed high stability with a variation range of 0.06 pF.

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References

  • Dai C (2007) A capacitive humidity sensor integrated with micro heater and ring oscillator circuit fabricated by CMOS-MEMS technique. Sens Actuators B Chem 122:375–380. doi:10.1016/j.snb.2006.05.042

    Article  Google Scholar 

  • Gerwen PV, Laureyn W, Laureys W, Huyberechts G, Beeck MOD, Baert K, Suls J, Sansen W, Jacobs P, Hermans L, Mertens R (1998) Nanoscaled interdigitated electrode arrays for biochemical sensors. Sens Actuators B Chem 49:73–80. doi:10.1016/S0925-4005(98)00128-2

    Article  Google Scholar 

  • Gu L, Huang Q, Qin M (2004) A novel capacitive-type humidity sensor using CMOS fabrication technology. Sens Actuators B Chem 99:491–498. doi:10.1016/j.snb.2003.12.060

    Article  Google Scholar 

  • Kang U, Wise K (2000) A high-speed capacitive humidity sensor with on-chip thermal reset. IEEE Trans Electron Devices 47:702–710. doi:10.1109/16.830983

    Article  Google Scholar 

  • Kim J, Hong S, Moon B (2010) High-performance capacitive humidity sensor with novel electrode and polyimide layer based on MEMS technology. Microsyst Technol 16:2017–2021. doi:10.1007/s00542-010-1139-0

    Article  Google Scholar 

  • Laconte J, Wilmart V, Flandre D, Raskin JP (2003) High-sensitivity capacitive humidity sensor using 3-layer patterned polyimide sensing film. In: Proceedings of IEEE sensors, pp 372–377

  • Laville C, Pellet C (2002) Interdigitated humidity sensors for a portable clinical microsystem. IEEE Trans Biomed Eng 49:1162–1167. doi:10.1109/TBME.2002.802052

    Article  Google Scholar 

  • Tetelin A, Pellet C (2006) Modeling and optimization of a fast response capacitive humidity sensor. IEEE Sens J 6:714–720. doi:10.1109/JSEN.2006.874446

    Article  Google Scholar 

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Acknowledgments

This work was supported by the R&D of GRRC.

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Authors and Affiliations

  1. Department of Electrical Engineering, Korea University, Seoul, 136-713, Korea

    Ji-Hong Kim & Byung-Moo Moon

  2. Korea Electronics Technology Institute, Seongnam, 463-816, Korea

    Sung-Min Hong

Authors
  1. Ji-Hong Kim
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  2. Byung-Moo Moon
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  3. Sung-Min Hong
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Correspondence to Byung-Moo Moon or Sung-Min Hong.

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Kim, JH., Moon, BM. & Hong, SM. Capacitive humidity sensors based on a newly designed interdigitated electrode structure. Microsyst Technol 18, 31–35 (2012). https://doi.org/10.1007/s00542-011-1373-0

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  • DOI: https://doi.org/10.1007/s00542-011-1373-0

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