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An interactive mouthguard based on mechanoluminescence-powered optical fibre sensors for bite-controlled device operation


Keyboards and touchscreens are widely used to control electronic devices, but these can be difficult to operate for individuals with dexterity impairments or neurological conditions. Several assistive technologies, such as voice recognition and eye tracking, have been developed to provide alternate methods of control. However, these can have problems in terms of use and maintenance. Here we report a bite-controlled optoelectronic system that uses mechanoluminescence-powered distributed-optical-fibre sensors that are integrated into mouthguards. Phosphors that are sensitive to mechanical stimulus are arranged in an array of contact pads in a flexible mouthguard; by using unique patterns of occlusal contacts in lateral positions, various forms of mechanical deformation can be distinguished by the fibre sensors via ratiometric luminescence measurements. By combining the device with machine learning algorithms, it is possible to translate complex bite patterns into specific data inputs with an accuracy of 98%. We show that interactive mouthguards can be used to operate computers, smartphones and wheelchairs.

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Fig. 1: Design of interactive mouthguard based on mp-DOF sensors.
Fig. 2: Characterization of mp-DOF-based sensors in various configurations.
Fig. 3: Evaluation of mp-DOF-integrated interactive mouthguard.
Fig. 4: Interactive mouthguard with a 2 × 3 mp-DOF array for assistive technology demonstration.
Fig. 5: Efficacy of the ANN-based interactive mouthguard using occlusal data from two users on specific tasks.

Data availability

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

Code availability

The code is available from the corresponding authors upon reasonable request.


  1. Yu, X. et al. Skin-integrated wireless haptic interfaces for virtual and augmented reality. Nature 575, 473–479 (2019).

    Article  Google Scholar 

  2. Zhou, Z. et al. Sign-to-speech translation using machine-learning-assisted stretchable sensor arrays. Nat. Electron. 3, 571–578 (2020).

    Article  Google Scholar 

  3. Bouton, C. E. et al. Restoring cortical control of functional movement in a human with quadriplegia. Nature 533, 247–250 (2016).

    Article  Google Scholar 

  4. Bai, H. D. et al. Stretchable distributed fiber-optic sensors. Science 370, 848–852 (2020).

    Article  Google Scholar 

  5. Cao, W. J. et al. Voice controlled wheelchair integration rehabilitation training and posture transformation for people with lower limb motor dysfunction. Technol. Health Care 29, 609–614 (2021).

    Article  Google Scholar 

  6. Pei, J. et al. Towards artificial general intelligence with hybrid Tianjic chip architecture. Nature 572, 106–111 (2019).

    Article  Google Scholar 

  7. Jin, P., Zou, J., Zhou, T. & Ding, N. Eye activity tracks task-relevant structures during speech and auditory sequence perception. Nat. Commun. 9, 5374 (2018).

    Article  Google Scholar 

  8. Oyama, A. et al. Novel method for rapid assessment of cognitive impairment using high-performance eye-tracking technology. Sci. Rep. 9, 12932 (2019).

    Article  Google Scholar 

  9. Lee, H., Park, S. H., Yoo, J. H., Jung, S. H. & Huh, J. H. Face recognition at a distance for a stand-alone access control system. Sensors 20, s20030785 (2020).

    Google Scholar 

  10. Guo, H. Y. et al. A highly sensitive, self-powered triboelectric auditory sensor for social robotics and hearing aids. Sci. Robot. 3, eaat2516 (2018).

    Article  Google Scholar 

  11. Nuyujukian, P. et al. Cortical control of a tablet computer by people with paralysis. PLoS ONE 13, e0204566 (2018).

    Article  Google Scholar 

  12. Willett, F. R., Avansino, D. T., Hochberg, L. R., Henderson, J. M. & Shenoy, K. V. High-performance brain-to-text communication via handwriting. Nature 593, 249–254 (2021).

    Article  Google Scholar 

  13. Kim, J. et al. Wearable salivary uric acid mouthguard biosensor with integrated wireless electronics. Biosens. Bioelectron. 74, 1061–1068 (2015).

    Article  Google Scholar 

  14. Verma, T. P., Kumathalli, K. I., Jain, V. & Kumar, R. Bite force recording devices—a review. J. Clin. Diagn. Res. 11, ZE01–ZE05 (2017).

    Google Scholar 

  15. Kim, T. et al. Heterogeneous sensing in a multifunctional soft sensor for human-robot interfaces. Sci. Robot. 5, eabc6878 (2020).

    Article  Google Scholar 

  16. Xu, P. A. et al. Optical lace for synthetic afferent neural networks. Sci. Robot. 4, eaaw6304 (2019).

    Article  Google Scholar 

  17. Li, G. et al. Self-powered soft robot in the Mariana Trench. Nature 591, 66–71 (2021).

    Article  Google Scholar 

  18. Guo, J., Zhou, B., Yang, C., Dai, Q. & Kong, L. Stretchable and temperature‐sensitive polymer optical fibers for wearable health monitoring. Adv. Funct. Mater. 29, 1902898 (2019).

    Article  Google Scholar 

  19. Lindsey, N. J., Dawe, T. C. & Ajo-Franklin, J. B. Illuminating seafloor faults and ocean dynamics with dark fiber distributed acoustic sensing. Science 366, 1103–1107 (2019).

    Article  Google Scholar 

  20. Butler, K. T., Davies, D. W., Cartwright, H., Isayev, O. & Walsh, A. Machine learning for molecular and materials science. Nature 559, 547–555 (2018).

    Article  Google Scholar 

  21. Qian, X. et al. Printable skin-driven mechanoluminescence devices via nanodoped matrix modification. Adv. Mater. 30, 1800291 (2018).

    Article  Google Scholar 

  22. Du, Y. et al. Mechanically excited multicolor luminescence in lanthanide ions. Adv. Mater. 31, 1807062 (2019).

    Article  Google Scholar 

  23. Zhao, Y. et al. Multiresponsive emissions in luminescent ions doped quaternary piezophotonic materials for mechanical‐to‐optical energy conversion and sensing applications. Adv. Funct. Mater. 31, 2010265 (2021).

    Article  Google Scholar 

  24. Wang, X. et al. Dynamic pressure mapping of personalized handwriting by a flexible sensor matrix based on the mechanoluminescence process. Adv. Mater. 27, 2324–2331 (2015).

    Article  Google Scholar 

  25. Zhang, J. et al. Flexible and stretchable mechanoluminescent fiber and fabric. J. Mater. Chem. C 5, 8027–8032 (2017).

    Article  Google Scholar 

  26. Pan, C. et al. High-resolution electroluminescent imaging of pressure distribution using a piezoelectric nanowire LED array. Nat. Photon. 7, 752–758 (2013).

    Article  Google Scholar 

  27. Zhao, X. et al. Self-powered user-interactive electronic skin for programmable touch operation platform. Sci. Adv. 6, eaba4294 (2020).

    Article  Google Scholar 

  28. Araromi, O. A. et al. Ultra-sensitive and resilient compliant strain gauges for soft machines. Nature 587, 219–224 (2020).

    Article  Google Scholar 

  29. Leber, A. et al. Soft and stretchable liquid metal transmission lines as distributed probes of multimodal deformations. Nat. Electron. 3, 316–326 (2020).

    Article  Google Scholar 

  30. Zhao, S. & Zhu, R. Electronic skin with multifunction sensors based on thermosensation. Adv. Mater. 29, 1606151 (2017).

    Article  Google Scholar 

  31. Chen, B., Zhang, X. & Wang, F. Expanding the toolbox of inorganic mechanoluminescence materials. Acc. Mater. Res. 2, 364–373 (2021).

    Article  Google Scholar 

  32. Chandra, V. K., Chandra, B. P. & Jha, P. Self-recovery of mechanoluminescence in ZnS:Cu and ZnS:Mn phosphors by trapping of drifting charge carriers. Appl. Phys. Lett. 103, 161113 (2013).

  33. Moon Jeong, S., Song, S., Lee, S.-K. & Choi, B. Mechanically driven light-generator with high durability. Appl. Phys. Lett. 102, 051110 (2013).

  34. Qasem, A., Xiong, P., Ma, Z., Peng, M. & Yang, Z. Recent advances in mechanoluminescence of doped zinc sulfides. Laser Photonics Rev. 15, 2100276 (2021).

  35. Wang, F. et al. Mechanoluminescence enhancement of ZnS:Cu,Mn with piezotronic effect induced trap-depth reduction originated from PVDF ferroelectric film. Nano Energy 63, 103861 (2019).

  36. Zhuang, Y. & Xie, R. J. Mechanoluminescence rebrightening the prospects of stress sensing: a review. Adv. Mater. 33, e2005925 (2021).

    Article  Google Scholar 

  37. Martincek, I., Pudis, D. & Chalupova, M. Technology for the preparation of PDMS optical fibers and some fiber structures. IEEE Photon. Technol. Lett. 26, 1446–1449 (2014).

    Article  Google Scholar 

  38. Missinne, J. et al. Stretchable optical waveguides. Opt. Express 22, 4168–4179 (2014).

    Article  Google Scholar 

  39. Harnett, C. K., Zhao, H. C. & Shepherd, R. F. Stretchable optical fibers: threads for strain-sensitive textiles. Adv. Mater. Technol. 2, 1700087 (2017).

    Article  Google Scholar 

  40. Leber, A., Cholst, B., Sandt, J., Vogel, N. & Kolle, M. Stretchable thermoplastic elastomer optical fibers for sensing of extreme deformations. Adv. Funct. Mater. 29, 1802629 (2019).

    Article  Google Scholar 

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This work is supported by the Ministry of Education Singapore (grant R-143-000-B43-114); Agency for Science, Technology and Research (A*STAR) (grant A1983c0038); National Research Foundation, Prime Minister’s Office, Singapore (CRP award no. NRF-NRFI05-2019-003 and NRF-CRP19-2017-01); National Basic Research Program of China (973 Program, grant 2015CB932200); and National Key R&D Program of China (YS2018YFB110012). We thank Yongan Tang, Zhuang Liu and Yong Zuo for their technical assistance.

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Authors and Affiliations



X.L., L.Y. and B.H. conceived and designed the project. X.L., B.Z. and R.Z. supervised the project and led the collaboration efforts. L.Y. characterized the materials and conducted the numerical simulations. C.L. completed the electrical device fabrication. B.H., L.Y. and H.Z. performed the luminescence measurements and conducted the experimental validation. B.H. and L.Y. wrote the manuscript. X.L., B.Z. and R.Z. edited the manuscript. All the authors participated in the discussion and analysis of the manuscript.

Corresponding authors

Correspondence to Bin Zhou or Xiaogang Liu.

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The authors declare no competing interests.

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Nature Electronics thanks Lin Dong, Meidan Ye and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–13 and Tables 1 and 2.

Supplementary Video 1

Characteristic of mp-DOF.

Supplementary Video 2

Keyboard type.

Supplementary Video 3

Wheelchair control and playing the piano.

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Hou, B., Yi, L., Li, C. et al. An interactive mouthguard based on mechanoluminescence-powered optical fibre sensors for bite-controlled device operation. Nat Electron 5, 682–693 (2022).

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