Ultra-thin sensors in ‘smart’ contact lenses could monitor user health
An international team of researchers has developed a ‘breakthrough’ sensor system and manufacturing process for new ‘smart’ contact lenses.
Engineers from the University of Surrey worked with partners from the UK National Physical Laboratory, Harvard University in Massachusetts, the University of Science and Technology of China, George Washington University in Washington DC and Zhejiang University Ningbo Research Institute in China to develop the ultra-thin sensors.
The new contact lens system contains a multitude of sensors – a photodetector for receiving optical information, a temperature sensor for diagnosing potential corneal disease and a glucose sensor for directly monitoring glucose levels in tear fluid.
“Our ultra-thin sensor layer is different from the conventional smart contact lenses with their rigid or bulk sensors, and circuit chips that are sandwiched between two contact lens layers,” said Dr Shiqi Guo, first author of the study and postdoctoral research fellow at Harvard University.
“This new layer could instead be mounted onto a contact lens and maintain direct contact with tears, thanks to its easy assembly, high detection sensitivity, good biocompatibility and mechanical robustness. Further, it doesn't interfere with either blinking or vision.”
Professor Sheng Zhang, co-author from Zhejiang University, said: “This multifunctional contact lens with field-effect transistors can provide diversified signals from eyes, which could be combined with advanced data analysis algorithms to provide personalised and accurate medical analysis for users.”
Dr Yunlong Zhao, co-author of the study and Surrey lecturer, said: “The Covid-19 pandemic has had an enormous impact on the entire scientific community, with many of us asking how our work could help those suffering from similar future medical emergencies. We are confident that devices that utilise our sensor layer system could be used as a non-invasive way to help monitor and diagnose people's health. Our results provide not only a unique and simple method for manufacturing advanced smart contact lenses but also novel insight for designing other multifunctional electronics for human-machine interface.”
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