Miniature humidity micro-sensor based on organic conductive polymer - poly(3,4-ethylenedioxythiophene)

L. Li, Filipe Vilela, John C Forgie, Peter J Skabara, D. Uttamchandani

Research output: Contribution to journalArticle

Abstract

A resistive micro-sensor for humidity sensing based on a conductive polymer material that is deposited electrochemically is presented. The resistor is formed by filling a narrow air gap (12 mu m) between two conductor pads with conductive poly(3,4-ethylenedioxythiophene) (PEDOT) polymer, and the resistance of the polymer micro-resistor thus formed is measured to be 41 Omega at a temperature of 20 degrees C. The conductor pads are prepared with a thick layer (20 mu m) of nickel using a multi-user microelectromechanical systems (MEMS) process. The area of the entire sensor is around 100 x 200 mu m, making it very compact. The humidity sensor has been characterised within a sealed chamber where the relative humidity is controlled by different saturated salt solutions at a constant temperature of 20 degrees C. The resistance of the sensor varies from 37 to 62 Omega from 22 to 99.9% of relative humidity at room temperature.

Original languageEnglish
Pages (from-to)84-87
Number of pages4
JournalMicro and Nano Letters
Volume4
Issue number2
DOIs
Publication statusPublished - Jun 2009

Keywords

  • POLYANILINE THIN-FILMS

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