A soft contact lens with an integrated LED microchip, RF antenna and stretchable interconnections has been created by scientists in Belgium and Japan. Made from a hydrogel-based material, the prototype device could lead to the development of contact lenses with integrated sensors and drug-delivery systems that could be used to treat diseases and injuries of the eye.
The contact lens was developed by Andrés Vásquez Quintero and colleagues at Belgium’s imec electronics research centre, the University of Ghent and SEED, which is a Japan-based maker of contact lenses.
Described as a “semi-passive smart lens”, the device is powered by an onboard RF antenna that converts radio waves to electrical currents. Signals sent and received via the antenna can also be used to control the on-board electronics and read data from measurements made by sensors.
The device comprises a ring-shaped flexible antenna and an electronics system that has a spherical curvature to match the curvature of the eye. Electrical connections between components are laid-out on a thermoplastic polyurethane (TPU) substrate that can be moulded to match the curvature of the eye. As well as being transparent, TPU is permeable to oxygen and has similar softness and flexibility as the hydrogel-based soft lens onto which the device is mounted.
“The integration of a LED light in a semi-passive RF wireless platform is the first important step towards a device that will change the life of many,” says Vásquez Quintero.
The team is now working towards the creation of active lenses with integrated transducers that can be powered over long periods of time. “Major challenges have to be overcome to make a truly autonomous smart lens that is comfortable to wear and stable for a few days or even weeks,” he says.
Ritsuko Arai of SEED says that such devices are suitable for mass production and could be installed on the inner or outer sides of a contact lens – or even within the lens itself. This, she says, could lead to a wide range of biosensing applications.