Biosensors Embedded in Contact Lenses for Human Health Monitoring

Abstract

This dissertation covers my graduate research about the development of micro biosensors which are embedded in soft contact lenses for human health monitoring in University of Washington. The work mainly focuses on two parts: the glucose sensors and the microbe sensors. As there are various informative physiological chemicals in tear fluids and a lot of eye diseases are related with bacterial invasion into the eye, biosensors embedded in contact lenses could pave a way to monitor human heath levels in a continuous and non-invasive way. In this work, glucose sensors have been developed and tested. The sensors were fabricated on plastic and parylene substrates, tested using the eye mimicking molds with artificial tear fluids, and integrated with wireless communication circuit. The parylene sensors were successfully molded into soft contact lenses and showed good characteristics such as linearity, repeatability, interference rejection property, temperature stability and protein fouling protection. Meanwhile, microbe sensors have also been constructed on parylene substrate and molded in soft contact lenses. By employing the antibody-antigen interaction and electrochemical impedance spectroscopy, the microbe sensors were tested for different concentrations of E.coli and P. aeruginosa, and further validated by biofilms. For the development of both glucose and microbe sensors, further work is necessary to make these biosensors more practical, such as optimizing the sensor design, improving the wireless transmission efficiency, realizing comfortable contact lenses and validating the sensors with animal or clinical experiment.