Fe3O4 magnetic enhanced CMOS MEMS compatible gas sensor

Shi Ching Ke, Chih-Hsiung Shen

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)


A new magnetic-catalytic sensing mechanism to increase sensitivity for CMOS MEMS gas sensor with mesh stacked sensing electrodes is proposed. Beyond the conventional power dissipation of heating to maintain a certain working temperature, a novel gas sensor with magnetic-catalytic mechanism works at the ambient temperature without the consideration of active heating. The design and fabrication is realized by the standard 0.35μm CMOS process to fabricate a gas sensor with mesh stacked electrodes. For the preparation of magnetic sensing material, a prepared solution of sol-gel SnO2 is mixed at SnO 2 : Fe3O4 = 3:1, which was deposited onto mesh stacked electrodes. Moreover, to obtain a stable gas sensing signal, a pulse sampling scheme is proposed in this research work. Since the resistance of sensing material with sol-gel deposition shows a drift behavior under a DC bias circuit. We have proposed a new signal reading scheme with a pulse-type bias for a bridge sensing circuit. Only under the sampling phase, the sensing current flows through the sensing material which induces a voltage drop across the resistance. For the CO concentration measurement, the sample is tested and verified inside a CO gas chamber with a magnetic field generator of solenoid coil. A careful investigation of measurement results, at horizontal magnetic field, the sensitivity of proposed CO gas sensor reaches 0.492%/ppm under the 12.12 Gauss which shows widely applicable for an ultra-low power chemical microsensor with high sensitivity.

Original languageEnglish
Title of host publication2013 IEEE International Conference of IEEE Region 10, IEEE TENCON 2013 - Conference Proceedings
Publication statusPublished - 2013 Dec 1
Event2013 IEEE International Conference of IEEE Region 10, IEEE TENCON 2013 - Xi'an, Shaanxi, China
Duration: 2013 Oct 222013 Oct 25

Publication series

NameIEEE Region 10 Annual International Conference, Proceedings/TENCON
ISSN (Print)2159-3442
ISSN (Electronic)2159-3450


Other2013 IEEE International Conference of IEEE Region 10, IEEE TENCON 2013
CityXi'an, Shaanxi

All Science Journal Classification (ASJC) codes

  • Computer Science Applications
  • Electrical and Electronic Engineering

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