A contact lens with integrated telecommunication circuit and sensors for wireless and continuous tear glucose monitoring

We present an integrated functional contact lens, composed of a differential glucose sensor module, metal interconnects, sensor read-out circuit, antenna and telecommunication circuit, to monitor tear glucose levels wirelessly, continuously and non-invasively. The electrochemical differential sensor module is based on immobilization of activated and de-activated glucose oxidase. We characterized the sensor on a model polymer eye and determined that it showed good repeatability, molecular interference rejection and linearity in the range of 0-2mM glucose, covering normal tear glucose concentrations (0.1-0.6mM). We also report the temperature, ageing and protein-fouling sensitivity of the sensor. We report the design and implementation of a low-power (3W) sensor read-out and telecommunication circuit to deliver wireless power and transmit data for the sensor module. Using this small chip (0.36mm ²), we produced an integrated contact lens with sensors and demonstrated wireless operation of the system and glucose read-out over the distance of several centimeters.