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Sensitive pressure sensors based on conductive microstructured air-gap gates and two-dimensional semiconductor transistors

Nature Electronics volume 3, pages 59–69 (2020)Cite this article

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Abstract

Microscopic pressure sensors that can rapidly detect small pressure variations are of value in robotic technologies, human–machine interfaces, artificial intelligence and health monitoring devices. However, both capacitive and transistor-based pressure sensors have limitations in terms of sensitivity, response speed, stability and power consumption. Here we show that highly sensitive pressure sensors can be created by integrating a conductive microstructured air-gap gate with two-dimensional semiconductor transistors. The air-gap gate can be used to create capacitor-based sensors that have tunable sensitivity and pressure-sensing range, exhibiting an average sensitivity of 44 kPa−1 in the 0–5 kPa regime and a peak sensitivity up to 770 kPa−1. Furthermore, by employing the air-gap gate as a pressure-sensitive gate for two-dimensional semiconductor transistors, the pressure sensitivity of the device can be amplified to ~103–107 kPa−1 at an optimized pressure regime of ~1.5 kPa. Our sensors also offer fast response speeds, low power consumption, low minimum pressure detection limits and excellent stability. We illustrate their capabilities by using them to perform static pressure mapping, real-time human pulse wave measurements, sound wave detection and remote pressure monitoring.

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Fig. 1: Capacitor- and transistor-based pressure sensors with CMAGs.
Fig. 2: Flexible CMAG capacitor-based pressure sensors.
Fig. 3: Tunability of the CMAG capacitor-based pressure sensors.
Fig. 4: Pressure-sensing performance of the CMAG-2D semiconductor transistor-based pressure sensors.
Fig. 5: Flexible CMAG capacitor-based pressure sensors for static pressure mapping and real-time pulse wave monitoring of the radial artery.
Fig. 6: CMAG-MoS2 pressure sensors for acoustic wave detection and related analysis.

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Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request.

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Acknowledgements

X.D. acknowledges support from the Office of Naval Research through grant no. N000141812707. Y.H. acknowledges support from the National Science Foundation (EFRI-1433541).

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Author notes

  1. These authors contributed equally: Yun-Chiao Huang, Yuan Liu.

Authors and Affiliations

  1. Department of Materials Science and Engineering, University of California, Los Angeles, CA, USA

    Yun-Chiao Huang, Yuan Liu, Chao Ma, Hung-Chieh Cheng, Hao Wu, Chen Wang & Yu Huang

  2. School of Physics and Electronics, Hunan University, Changsha, China

    Yuan Liu

  3. Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA

    Qiyuan He & Xiangfeng Duan

  4. Department of Electrical Engineering, University of California, Los Angeles, CA, USA

    Cheng-Yi Lin

  5. California NanoSystems Institute, University of California, Los Angeles, CA, USA

    Yu Huang & Xiangfeng Duan

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Contributions

X.D., Y.H. and Y.-C.H. designed the experiments. Y.-C.H. performed most of the experiments including device fabrication, electrical/pressure measurements, signal processing and data analysis. Y.L. contributed to the fabrication of the flexible CMAG-WSe2 pressure sensor and related measurements. H.-C.C. contributed to the pulse wave measurements, designed the schematic illustrations and revised the first version of the manuscript. C.M. and Y.-C.H. discussed the simulation together, and C.M. executed the simulation. Q.H. contributed to the surface treatment of the microstructured moulds and gave valued feedback about the experimental results. H.W. contributed to the dielectric and electrode fabrication. C.W. provided ALD technical support. C.-Y.L. contributed to the remote pressure monitoring system. X.D., Y.H. and Y.-C.H. co-wrote the paper. All authors discussed the results and commented on the manuscript.

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Correspondence to Yu Huang or Xiangfeng Duan.

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Huang, YC., Liu, Y., Ma, C. et al. Sensitive pressure sensors based on conductive microstructured air-gap gates and two-dimensional semiconductor transistors. Nat Electron 3, 59–69 (2020). https://doi.org/10.1038/s41928-019-0356-5

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