Rather than relying on impermeable elastomeric polymers, the new device was based on a hydrogel-based material, opening the door to unique applications such as lenses with sensors and/or drug-delivery systems for the treatment of different eye disorders, at the congenital, post-surgery or trauma level. Such a wearable sensor-laden lens could perform continuous monitoring in an almost imperceptible manner.
About 130 million people worldwide wear contact lenses, mainly to correct their vision. Now, with electronic systems getting ever smaller and with the possibility of having electrical power on-lens, it becomes feasible to integrate a variety of transducers (i.e. physical, biochemical, etc.) into a lens. This is interesting for diagnosing and treating ocular diseases. The challenge is to integrate a complete autonomous system and make it as flexible as a soft lens, without compromising its oxygen-permeable nature and the integrity of the electronics components.
CMST, an imec research group at Ghent University, together with SEED Co., Ltd., demonstrated a semi-passive smart lens with blue LED light powered by an RF coupling. Besides power transfer, the RF link can be used to calibrate the integrated transducers and reading the sensors out into a handheld device for further post-processing.
The spherical‐shaped electronics were made by imec/CMST, whereas SEED Co., Ltd. was responsible for the seamless integration into the hydrogel-based soft lens.
The interconnect substrate is based on thermoplastic polyurethane (TPU), a material with a low glass transition temperature, relatively low hardness, proven biocompatibility, optical transparency, conformal fitting, oxygen permeability, and flexibility comparable with soft contact lenses (e.g., hydrogel‐based).