Article

Flexible polymer transistors with high pressure sensitivity for application in electronic skin and health monitoring

  • Nature Communications 4, Article number: 1859 (2013)
  • doi:10.1038/ncomms2832
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Abstract

Flexible pressure sensors are essential parts of an electronic skin to allow future biomedical prostheses and robots to naturally interact with humans and the environment. Mobile biomonitoring in long-term medical diagnostics is another attractive application for these sensors. Here we report the fabrication of flexible pressure-sensitive organic thin film transistors with a maximum sensitivity of 8.4 kPa−1, a fast response time of <10 ms, high stability over >15,000 cycles and a low power consumption of <1 mW. The combination of a microstructured polydimethylsiloxane dielectric and the high-mobility semiconducting polyisoindigobithiophene-siloxane in a monolithic transistor design enabled us to operate the devices in the subthreshold regime, where the capacitance change upon compression of the dielectric is strongly amplified. We demonstrate that our sensors can be used for non-invasive, high fidelity, continuous radial artery pulse wave monitoring, which may lead to the use of flexible pressure sensors in mobile health monitoring and remote diagnostics in cardiovascular medicine.

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Acknowledgements

G.S. was supported by the Deutsche Forschungsgemeinschaft (SCHW 1556/2-1). B.C-K.T. is supported by the National Science Scholarship (NSS) from the Agency of Science Technology and Research (A*STAR) Singapore. This work is partially supported by the National Science Foundation (Grant number: ECCS 1101901), the Air Force Office for Scientific Research (FA9550-12-1-01900) and the Dreyfus Foundation Environmental Postdoctoral Program.

Author information

Author notes

    • Do Hwan Kim

    Present address: Department of Organic Materials and Fiber Engineering, 369 Sangdo-Ro, Dongjak-Gu, Soongsil University, Seoul 156-743, Korea

Affiliations

  1. Department of Chemical Engineering, Stanford University, 381 North South Mall, Stanford, California 94305, USA

    • Gregor Schwartz
    • , Jianguo Mei
    • , Anthony L. Appleton
    • , Do Hwan Kim
    •  & Zhenan Bao
  2. Department of Electrical Engineering, Stanford University, 350 Serra Mall, Stanford, California 94305, USA

    • Benjamin C.-K. Tee
  3. Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305, USA

    • Huiliang Wang

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Contributions

Z.B., G.S., and B.C.-K.T. conceptualized the work. G.S. carried out most of the device development and experimental work. B.C.-K.T. helped with many experimental set-ups and array fabrication. J.M. and A.L.A. synthesized the semiconducting polymer. D.H.K. helped with device fabrication. H.W. helped with lithography and SEM pictures. G.S. wrote the first draft of the manuscript. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Zhenan Bao.

Supplementary information

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    Supplementary Information

    Supplementary Figures S1-S8 and Supplementary Table S1

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