We report on the experimentally observed reliability of the piezoresistive effect in strained poly 3,4-ethylenedioxythiophene (PEDT). PEDT is an intrinsic conductive polymer which can be patterned by conventional Cleanroom processing, and thus presents a promising material for all-polymer Microsystems. The measurements are made on microfabricated test chips with PEDT resistors patterned by conventional UV-lithography and reactive ion etching (RIE). We determine a gauge factor of 3.41 ± 0.42 for the strained PEDT and we see an increase in resistivity from 1.98 · 104 X m to 2.22 · 104 X m when the polymer is immersed in water for 30 min. The resistivity continues to increase to 2.66 · 104 X m when the resistor is thermally dried due to interactions with oxygen from the ambient. We measure the PEDT sheet resistance over a period of four weeks and see small fluctuations caused by humidity variations. 2007 Elsevier B.V. All rights reserved.
- All-polymer sensors
- Piezoresistive polymer
- Conducting polymer
Mateiu, R. V., Lillemose, M., Hansen, T. S., Boisen, A., & Geschke, O. (2007). Reliability of poly 3,4-ethylenedioxythiophene strain gauge. Microelectronic Engineering, 84, 1270-1273. https://doi.org/10.1016/j.mee.2007.01.192