Engineers have developed a sensor system and manufacturing process for smart contact lenses. The sensor system contains a photodetector for receiving optical information, a temperature sensor for diagnosing potential corneal disease, and a glucose sensor for directly monitoring the glucose levels in tear fluid.
The ultra-thin sensor layer is different from the conventional smart contact lenses that have rigid or bulk sensors and circuit chips sandwiched between two contact lens layers and make contact with tear fluids via microfluidic sensing channels. The new layer could instead be mounted onto a contact lens and maintain direct contact with tears, thanks to high detection sensitivity, good biocompatibility, and mechanical robustness. It also does not interfere with either blinking or vision.
The multifunctional contact lens with field-effect transistors can provide diversified signals from eyes, which could be combined with advanced data analysis algorithms to provide personalized and accurate medical analysis for users.
Devices that utilize the sensor layer system could be used as a non-invasive way to help monitor and diagnose people’s health. The method for manufacturing advanced smart contact lenses could be used for designing other multifunctional electronics for human-machine interface.