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

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.

References

  1. Jung, S. et al. Reverse-micelle-induced porous pressure-sensitive rubber for wearable human–machine interfaces. Adv. Mater. 26, 4825–4830 (2014).

    Google Scholar 

  2. Kang, D. et al. Ultrasensitive mechanical crack-based sensor inspired by the spider sensory system. Nature 516, 222–226 (2014).

    Google Scholar 

  3. Kim, D.-H. et al. Epidermal electronics. Science 333, 838–843 (2011).

    Google Scholar 

  4. Lipomi, D. J. et al. Skin-like pressure and strain sensors based on transparent elastic films of carbon nanotubes. Nat. Nanotechnol. 6, 788–792 (2011).

    Google Scholar 

  5. Tee, B. C.-K. et al. A skin-inspired organic digital mechanoreceptor. Science 350, 313–316 (2015).

    Google Scholar 

  6. Yeom, C. et al. Large-area compliant tactile sensors using printed carbon nanotube active-matrix backplanes. Adv. Mater. 27, 1561–1566 (2015).

    Google Scholar 

  7. Schwartz, G. et al. Flexible polymer transistors with high pressure sensitivity for application in electronic skin and health monitoring. Nat. Commun. 4, 1859 (2013).

    Google Scholar 

  8. Zang, Y. et al. Flexible suspended gate organic thin-film transistors for ultra-sensitive pressure detection. Nat. Commun. 6, 6269 (2015).

    Google Scholar 

  9. Mannsfeld, S. C. et al. Highly sensitive flexible pressure sensors with microstructured rubber dielectric layers. Nat. Mater. 9, 859–864 (2010).

    Google Scholar 

  10. Lee, S. et al. A transparent bending-insensitive pressure sensor. Nat. Nanotechnol. 11, 472–478 (2016).

    Google Scholar 

  11. Graz, I. et al. Flexible ferroelectret field-effect transistor for large-area sensor skins and microphones. Appl. Phys. Lett. 89, 073501 (2006).

    Google Scholar 

  12. Dellon, E. S., Mourey, R. & Dellon, A. L. Human pressure perception values for constant and moving one-and two-point discrimination. Plast. Reconstr. Surg. 90, 112–117 (1992).

    Google Scholar 

  13. Kaltenbrunner, M. et al. An ultra-lightweight design for imperceptible plastic electronics. Nature 499, 458–463 (2013).

    Google Scholar 

  14. Pan, L. et al. An ultra-sensitive resistive pressure sensor based on hollow-sphere microstructure induced elasticity in conducting polymer film. Nat. Commun. 5, 3002 (2014).

    Google Scholar 

  15. Pang, C. et al. A flexible and highly sensitive strain-gauge sensor using reversible interlocking of nanofibres. Nat. Mater. 11, 795–801 (2012).

    Google Scholar 

  16. Chae, S. H. et al. Transferred wrinkled Al2O3 for highly stretchable and transparent graphene–carbon nanotube transistors. Nat. Mater. 12, 403–409 (2013).

    Google Scholar 

  17. Metzger, C. et al. Flexible-foam-based capacitive sensor arrays for object detection at low cost. Appl. Phys. Lett. 92, 013506 (2008).

    Google Scholar 

  18. Lee, J. et al. Conductive fiber-based ultrasensitive textile pressure sensor for wearable electronics. Adv. Mater. 27, 2433–2439 (2015).

    Google Scholar 

  19. Lee, H.-K., Chang, S.-I. & Yoon, E. A flexible polymer tactile sensor: fabrication and modular expandability for large area deployment. J. Microelectromech. Syst. 15, 1681–1686 (2006).

    Google Scholar 

  20. Sekitani, T. et al. Organic nonvolatile memory transistors for flexible sensor arrays. Science 326, 1516–1519 (2009).

    Google Scholar 

  21. Takei, K. et al. Nanowire active-matrix circuitry for low-voltage macroscale artificial skin. Nat. Mater. 9, 821–826 (2010).

    Google Scholar 

  22. Lee, B.-Y., Kim, J., Kim, H., Kim, C. & Lee, S.-D. Low-cost flexible pressure sensor based on dielectric elastomer film with micro-pores. Sens. Actuators A Phys. 240, 103–109 (2016).

    Google Scholar 

  23. Lei, K. F., Lee, K.-F. & Lee, M.-Y. A flexible PDMS capacitive tactile sensor with adjustable measurement range for plantar pressure measurement. Microsyst. Technol. 20, 1351–1358 (2014).

    Google Scholar 

  24. Zhang, B. et al. Dual functional transparent film for proximity and pressure sensing. Nano Res. 7, 1488–1496 (2014).

    Google Scholar 

  25. Park, S. et al. Stretchable energy-harvesting tactile electronic skin capable of differentiating multiple mechanical stimuli modes. Adv. Mater. 26, 7324–7332 (2014).

    Google Scholar 

  26. Boutry, C. M. et al. A sensitive and biodegradable pressure sensor array for cardiovascular monitoring. Adv. Mater. 27, 6954–6961 (2015).

    Google Scholar 

  27. Pang, C. et al. Highly skin-conformal microhairy sensor for pulse signal amplification. Adv. Mater. 27, 634–640 (2015).

    Google Scholar 

  28. Tee, B. C. K. et al. Tunable flexible pressure sensors using microstructured elastomer geometries for intuitive electronics. Adv. Funct. Mater. 24, 5427–5434 (2014).

    Google Scholar 

  29. Pannemann, C., Diekmann, T. & Hilleringmann, U. Degradation of organic field-effect transistors made of pentacene. J. Mater. Res. 19, 1999–2002 (2004).

    Google Scholar 

  30. Sirringhaus, H. Reliability of organic field-effect transistors. Adv. Mater. 21, 3859–3873 (2009).

    Google Scholar 

  31. Manunza, I. & Bonfiglio, A. Pressure sensing using a completely flexible organic transistor. Biosens. Bioelectron. 22, 2775–2779 (2007).

    Google Scholar 

  32. Wang, Z., Volinsky, A. A. & Gallant, N. D. Crosslinking effect on polydimethylsiloxane elastic modulus measured by custom-built compression instrument. J. Appl. Polym. Sci. 131, 41050 (2014).

    Google Scholar 

  33. Chuang, H.-J. et al. High mobility WSe2 p-and n-type field-effect transistors contacted by highly doped graphene for low-resistance contacts. Nano Lett. 14, 3594–3601 (2014).

    Google Scholar 

  34. Zhao, W. et al. Evolution of electronic structure in atomically thin sheets of WS2 and WSe2. ACS Nano 7, 791–797 (2012).

    Google Scholar 

  35. Bertolazzi, S., Brivio, J. & Kis, A. Stretching and breaking of ultrathin MoS2. ACS Nano 5, 9703–9709 (2011).

    Google Scholar 

  36. Radisavljevic, B., Radenovic, A., Brivio, J., Giacometti, V. & Kis, A. Single-layer MoS2 transistors. Nat. Nanotechnol. 6, 147–150 (2011).

    Google Scholar 

  37. Kim, S. et al. High-mobility and low-power thin-film transistors based on multilayer MoS2 crystals. Nat. Commun. 3, 1011 (2012).

    Google Scholar 

  38. Zhao, M. et al. Large-scale chemical assembly of atomically thin transistors and circuits. Nat. Nanotechnol 11, 954–959 (2016).

    Google Scholar 

  39. Cheng, R. et al. Few-layer molybdenum disulfide transistors and circuits for high-speed flexible electronics. Nat. Commun. 5, 5143 (2014).

    Google Scholar 

  40. Noguchi, Y., Sekitani, T. & Someya, T. Organic-transistor-based flexible pressure sensors using ink-jet-printed electrodes and gate dielectric layers. Appl. Phys. Lett. 89, 3507 (2006).

    Google Scholar 

  41. Takahashi, T., Takei, K., Gillies, A. G., Fearing, R. S. & Javey, A. Carbon nanotube active-matrix backplanes for conformal electronics and sensors. Nano Lett. 11, 5408–5413 (2011).

    Google Scholar 

  42. Nichols, W. W. Clinical measurement of arterial stiffness obtained from noninvasive pressure waveforms. Am. J. Hypertens. 18, 3S–10S (2005).

    Google Scholar 

  43. Millasseau, S., Kelly, R., Ritter, J. & Chowienczyk, P. Determination of age-related increases in large artery stiffness by digital pulse contour analysis. Clin. Sci. 103, 371–377 (2002).

    Google Scholar 

  44. Munir, S. et al. Exercise reduces arterial pressure augmentation through vasodilation of muscular arteries in humans. Am. J. Physiol. Heart Circ. Physiol. 294, H1645–H1650 (2008).

    Google Scholar 

  45. Saunders, F. A., Hill, W. A. & Franklin, B. A wearable tactile sensory aid for profoundly deaf children. J. Med. Syst. 5, 265–270 (1981).

    Google Scholar 

  46. Yang, J. et al. Eardrum-inspired active sensors for self-powered cardiovascular system characterization and throat-attached anti-interference voice recognition. Adv. Mater. 27, 1316–1326 (2015).

    Google Scholar 

  47. Kang, K. et al. High-mobility three-atom-thick semiconducting films with wafer-scale homogeneity. Nature 520, 656–630 (2015).

    Google Scholar 

  48. Yu, H. et al. Wafer-scale growth and transfer of highly-oriented monolayer MoS2 continuous films. ACS Nano 11, 12001–12007 (2017).

    Google Scholar 

  49. Xu, H. et al. High-performance wafer-scale MoS2 transistors toward practical application. Small 14, 1803465 (2018).

    Google Scholar 

  50. Lin, Z. et al. Solution-processable 2D semiconductors for high-performance large-area electronics. Nature 562, 254–258 (2018).

    Google Scholar 

  51. Lacour, S. P., Wagner, S., Huang, Z. & Suo, Z. Stretchable gold conductors on elastomeric substrates. Appl. Phys. Lett. 82, 2404–2406 (2003).

    Google Scholar 

  52. Lacour, S. P., Jones, J., Wagner, S., Li, T. & Suo, Z. Stretchable interconnects for elastic electronic surfaces. Proc. IEEE 93, 1459–1467 (2005).

    Google Scholar 

  53. Graz, I. M., Cotton, D. P. & Lacour, S. P. Extended cyclic uniaxial loading of stretchable gold thin-films on elastomeric substrates. Appl. Phys. Lett. 94, 071902 (2009).

    Google Scholar 

  54. Chou, H.-H. et al. A chameleon-inspired stretchable electronic skin with interactive colour changing controlled by tactile sensing. Nat. Commun. 6, 8011 (2015).

    Google Scholar 

  55. Roberts, M. E. et al. Cross-linked polymer gate dielectric films for low-voltage organic transistors. Chem. Mater. 21, 2292–2299 (2009).

    Google Scholar 

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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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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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Supplementary Figs. 1–23 and Notes 1–4.

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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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