Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Stretchable temperature-sensing circuits with strain suppression based on carbon nanotube transistors

Nature Electronics volume 1, pages 183–190 (2018)Cite this article

Subjects

Abstract

For the next generation of wearable health monitors, it is essential to develop stretchable and conformable sensors with robust electrical performance. These sensors should, in particular, provide a stable electrical output without being affected by external variables such as induced strain. Here, we report circuit design strategies that can improve the accuracy and robustness of a temperature sensor based on stretchable carbon nanotube transistors. Using static and dynamic differential readout approaches, our circuits suppress strain-dependent errors and achieve a measured inaccuracy of only ±1 oC within a uniaxial strain range of 0–60%. We address device variability by using a one-time, single-point calibration approach. In contrast with previous approaches, which infer temperature change through a normalized measurement at two temperatures, our prototype devices provide an absolute output without temperature cycling. This is essential for practical deployment because heating and cooling the sensor is prohibitively slow and costly during real-time operation and production testing.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Stretchable integrated circuit for strain-independent temperature sensing.
Fig. 2: Stretchable SWCNT TFTs for circuits.
Fig. 3: Temperature dependence of the stretchable TFT devices.
Fig. 4: Performance of stretchable temperature sensors based on static differential sensing circuit architecture.
Fig. 5: Performance of stretchable temperature sensors based on dynamic differential sensing circuit architecture.

Similar content being viewed by others

References

  1. Gao, W. et al. Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis. Nature 529, 509–514 (2016).

    Article  Google Scholar 

  2. Park, S. I. et al. Soft, stretchable, fully implantable miniaturized optoelectronic systems for wireless optogenetics. Nat. Biotechnol. 33, 1280–1286 (2015).

    Article  Google Scholar 

  3. Chortos, A., Liu, J. & Bao, Z. Pursuing prosthetic electronic skin. Nat. Mater. 15, 937–950 (2016).

    Article  Google Scholar 

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

    Article  Google Scholar 

  5. Wehner, M. et al. An integrated design and fabrication strategy for entirely soft, autonomous robots. Nature 536, 451–455 (2016).

    Article  Google Scholar 

  6. Gupta, S. & Loh, K. J. Noncontact electrical permittivity mapping and pH-sensitive films for osseointegrated prosthesis and infection monitoring. IEEE Trans. Med. Imag. 36, 2193–2202 (2017).

    Article  Google Scholar 

  7. Lee, S. et al. A strain-absorbing design for tissue–machine interfaces using a tunable adhesive gel. Nat. Commun. 5, 5898 (2014).

    Article  Google Scholar 

  8. Soekadar, S. R. et al. Hybrid EEG/EOG-based brain/neural hand exoskeleton restores fully independent daily living activities after quadriplegia. Sci. Robot. 1, eaag3296 (2016).

    Article  Google Scholar 

  9. Meijer, G., Pertijs, M. & Makinwa, K. Smart Sensor Systems: Emerging Technologies and Applications (Wiley, New York, NY, 2014).

    Book  Google Scholar 

  10. Hsu, Y.-C. et al. An 18.75 μW dynamic-distributing-bias temperature sensor with 0.87°C (3σ) untrimmed inaccuracy and 0.00946 mm2 area. 2017 IEEE Int. Solid-State Circuits Conf. https://doi.org/10.1109/ISSCC.2017.7870281 (2017).

  11. Yousefzadeh, B., Shalmany, S. H. & Makinwa, K. A. A. A BJT-based temperature-to-digital converter with ±60 mK (3σ) inaccuracy from −55 °C to +125 °C in 0.16-μm CMOS. IEEE J. Solid-State Circuits 52, 1044–1052 (2017).

    Article  Google Scholar 

  12. Deng, C. et al. A CMOS smart temperature sensor with single-point calibration method for clinical use. IEEE Trans. Circuits Syst. II 63, 136–139 (2016).

    Article  Google Scholar 

  13. Ha, D. et al. Time-domain CMOS temperature sensors with dual delay-locked loops for microprocessor thermal monitoring. IEEE Trans. Very Large Scale Integr. Syst. 20, 1590–1601 (2012).

    Article  Google Scholar 

  14. Hattori, Y. et al. Multifunctional skin-like electronics for quantitative, clinical monitoring of cutaneous wound healing. Adv. Healthcare Mater. 3, 1597–1607 (2014).

    Article  Google Scholar 

  15. Jin, H., Abu-Raya, Y. S. & Haick, H. Advanced materials for health monitoring with skin-based wearable devices. Adv. Healthcare Mater. 6, 1700024 (2017).

    Article  Google Scholar 

  16. Yokota, T. et al. Ultra-flexible, large-area, physiological temperature sensors for multipoint measurements. Proc. Natl Acad. Sci. USA 112, 14533–14538 (2015).

    Article  Google Scholar 

  17. Kim, D.-H. et al. Materials for multifunctional balloon catheters with capabilities in cardiac electrophysiological mapping and ablation therapy. Nat. Mater. 10, 316–323 (2011).

    Article  Google Scholar 

  18. Xu, L. et al. 3D multifunctional integumentary membranes for spatiotemporal cardiac measurements and stimulation across the entire epicardium. Nat. Commun. 5, 3329 (2014).

    Google Scholar 

  19. Yan, C., Wang, J. & Lee, P. S. Stretchable graphene thermistor with tunable thermal index. ACS Nano 9, 2130–2137 (2015).

    Article  Google Scholar 

  20. Trung, T. Q., Ramasundaram, S., Hwang, B.-U. & Lee, N.-E. An all-elastomeric transparent and stretchable temperature sensor for body-attachable wearable electronics. Adv. Mater. 28, 502–509 (2016).

    Article  Google Scholar 

  21. Khan, Y., Ostfeld, A. E., Lochner, C. M., Pierre, A. & Arias, A. C. Monitoring of vital signs with flexible and wearable medical devices. Adv. Mater. 28, 4373–4395 (2016).

    Article  Google Scholar 

  22. Webb, R. C. et al. Ultrathin conformal devices for precise and continuous thermal characterization of human skin. Nat. Mater. 12, 938–944 (2013).

    Article  Google Scholar 

  23. Salowitz, N. P. et al. Microfabricated expandable sensor networks for intelligent sensing materials. IEEE Sens. J. 14, 2138–2144 (2014).

    Article  Google Scholar 

  24. Chortos, A. et al. Mechanically durable and highly stretchable transistors employing carbon nanotube semiconductor and electrodes. Adv. Mater. 28, 4441–4448 (2016).

    Article  Google Scholar 

  25. Pochorovski, I. et al. H-bonded supramolecular polymer for the selective dispersion and subsequent release of large-diameter semiconducting single-walled carbon nanotubes. J. Am. Chem. Soc. 137, 4328–4331 (2015).

    Article  Google Scholar 

  26. Lei, T., Pochorovski, I. & Bao, Z. Separation of semiconducting carbon nanotubes for flexible and stretchable electronics using polymer removable method. Acc. Chem. Res. 50, 1096–1104 (2017).

    Article  Google Scholar 

  27. Wang, Y. et al. A highly stretchable, transparent, and conductive polymer. Sci. Adv. 3, e1602076 (2017).

    Article  Google Scholar 

  28. Xu, J. et al. Highly stretchable polymer semiconductor films through the nanoconfinement effect. Science 355, 59–64 (2017).

    Article  Google Scholar 

  29. Li, Y. & Shimizu, H. Toward a stretchable, elastic, and electrically conductive nanocomposite: morphology and properties of poly[styrene-b-(ethylene-co-butylene)-b-styrene]/multiwalled carbon nanotube composites fabricated by high-shear processing. Macromolecules 42, 2587–2593 (2009).

    Article  Google Scholar 

  30. Chortos, A. et al. Investigating limiting factors in stretchable all-carbon transistors for reliable stretchable electronics. ACS Nano 11, 7925–7937 (2017).

    Article  Google Scholar 

  31. Wang, H. & Bao, Z. Conjugated polymer sorting of semiconducting carbon nanotubes and their electronic applications. Nano Today 10, 737–758 (2016).

    Article  Google Scholar 

  32. Zhou, X. J., Park, J. Y., Huang, S. M., Liu, J. & McEuen, P. L. Band structure, phonon scattering, and the performance limit of single-walled carbon nanotube transistors. Phys. Rev. Lett. 95, 146805 (2005).

    Article  Google Scholar 

  33. Gao, J. & Loo, Y.-L. Temperature-dependent electrical transport in polymer-sorted semiconducting carbon nanotube networks. Adv. Funct. Mater. 25, 105–110 (2015).

    Article  Google Scholar 

  34. Yao, Z., Postma, H. W. C., Balents, L. & Dekker, C. Carbon nanotube intramolecular junctions. Nature 402, 273–276 (1999).

    Article  Google Scholar 

  35. Rother, M. et al. Understanding charge transport in mixed networks of semiconducting carbon nanotubes. ACS Appl. Mater. Interfaces 8, 5571–5579 (2016).

    Article  Google Scholar 

  36. Murmann, B. Analysis and Design of Elementary MOS Amplifier Stages (NTS Press, Austin, TX, 2013).

    Google Scholar 

  37. Cai, L., Zhang, S., Miao, J., Yu, Z. & Wang, C. Fully printed stretchable thin-film transistors and integrated logic circuits. ACS Nano 10, 11459–11468 (2016).

    Article  Google Scholar 

  38. Huang, C.-C., Kao, Z.-K. & Liao, Y.-C. Flexible miniaturized nickel oxide thermistor arrays via inkjet printing technology. ACS Appl. Mater. Interfaces 5, 12954–12959 (2013).

    Google Scholar 

  39. Lee, S. W. et al. Positive gate bias stress instability of carbon nanotube thin film transistors. Appl. Phys. Lett. 101, 053504 (2012).

    Article  Google Scholar 

  40. Markenscoff, X. & Yannas, I. V. On the stress–strain relation for skin. J. Biomech. 12, 127–129 (1979).

    Article  Google Scholar 

Download references

Acknowledgements

The authors thank M. Claus for helpful discussion on compact model development and F. Lian for the help of collecting SEM images. This work was supported by Samsung Electronics. R.P. acknowledges support from Marie Curie Cofund, Beatriu de Pinós fellowship (AGAUR 2014 BP-A 00094). A.C.H. acknowledges support from the National Science Foundation Graduate Research Fellowship (grant no. DGE-1147474).

Author information

Authors and Affiliations

  1. Department of Electrical Engineering, Stanford University, Stanford, CA, USA

    Chenxin Zhu & Boris Murmann

  2. Department of Materials Science & Engineering, Stanford University, Stanford, CA, USA

    Alex Chortos

  3. Department of Chemical Engineering, Stanford University, Stanford, CA, USA

    Yue Wang, Raphael Pfattner, Ting Lei, Allison Claire Hinckley, Igor Pochorovski, Xuzhou Yan, John W.-F. To, Jin Young Oh, Jeffery B.-H. Tok & Zhenan Bao

Authors
  1. Chenxin Zhu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Alex Chortos
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Yue Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Raphael Pfattner
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Ting Lei
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Allison Claire Hinckley
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Igor Pochorovski
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Xuzhou Yan
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. John W.-F. To
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Jin Young Oh
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Jeffery B.-H. Tok
    View author publications

    You can also search for this author in PubMed Google Scholar

  12. Zhenan Bao
    View author publications

    You can also search for this author in PubMed Google Scholar

  13. Boris Murmann
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

C.Z. and B.M. conceived the concept. C.Z., B.M. and Z.B. conceived the experiments. C.Z., A.C., Y.W. and T.L. developed the fabrication processes. C.Z. and R.P. performed data collection and analysis of temperature-dependence for transistors. A.C.H., C.Z. and J.Y.O. designed the test station with strain and temperature. X.Y. and I.P. synthesized the supramolecular sorting polymer. J.W.-F.T. collected SEM images. Z.B. and B.M. supervised the project. All authors provided comments for the manuscript.

Corresponding authors

Correspondence to Zhenan Bao or Boris Murmann.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figures 1–11 and Supplementary Table 1

Supplementary Video 1

Demonstration of stretchable temperature sensor attached to the knuckle area of a flexible rubber prosthetic hand

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Zhu, C., Chortos, A., Wang, Y. et al. Stretchable temperature-sensing circuits with strain suppression based on carbon nanotube transistors. Nat Electron 1, 183–190 (2018). https://doi.org/10.1038/s41928-018-0041-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41928-018-0041-0

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing