Integrated contact lens sensor system based on multifunctional ultrathin MoS ₂ transistors

Abstract

Smart contact lenses attract extensive interests due to their capability of directly monitoring physiological and ambient information. However, previous demonstrations usually lacked efficient sensor modalities, facile fabrication process, mechanical stability, or biocompatibility. Here, we demonstrate a flexible approach for fabrication of multifunctional smart contact lenses with an ultrathin MoS ₂ transistors-based serpentine mesh sensor system. The integrated sensor systems contain a photodetector for receiving optical information, a glucose sensor for monitoring glucose level directly from tear fluid, and a temperature sensor for diagnosing potential corneal disease. Unlike traditional sensors and circuit chips sandwiched in the lens substrate, this serpentine mesh sensor system can be directly mounted onto the lenses and maintain direct contact with tears, delivering high detection sensitivity, while being mechanically robust and not interfering with either blinking or vision. Furthermore, the in vitro cytotoxicity tests reveal good biocompatibility, thus holding promise as next-generation soft electronics for healthcare and medical applications.

Graphical abstract

Highlights

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  Smart contact lenses integrate photodetectors, glucose sensors, and temperature sensors

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  Ultrathin serpentine mesh sensor layer can be directly mounted onto the contact lens

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  Sensor layer directly contacts with tears and does not interfere with blinking or vision

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  It shows high detection sensitivity, good biocompatibility, and mechanical robustness

Progress and potential

Wearable smart contact lenses have attracted extensive interests because of their ability to monitor physiological information and ambient information directly from eyeball and body fluids. However, conventional smart contact lens systems lack efficient sensor modalities, facile fabrication process, mechanical stability, or biocompatibility. This study develops a multifunctional, high-transparency and easy-access smart contact lens system. Specifically, the serpentine mesh sensor system can be directly mounted onto the lens substrate and maintain direct contact with tears, delivering high detection sensitivity, while being mechanically robust and not interfering with either blinking or vision. This integrated contact lens sensor system and fabrication strategy allows for easy incorporation of other functional components, such as an electrode array for electroretinography, antennas for wireless communication, and power modules for future in vivo exploration.

Abstract

A multifunctional smart contact lens with an ultrathin MoS ₂ transistors-based serpentine mesh sensor system was developed, featuring easy assembly, good detection sensitivity, strong robustness, high stretchability, transparency, and full biocompatibility. The integrated sensor systems contain a photodetector for receiving optical information, imaging and vision assistance, a temperature sensor for diagnosing potential corneal disease, and a glucose sensor for monitoring glucose levels directly from the tear fluid.