Power Scavenging Microsystem for Smart Contact Lenses

Abstract

On‐the‐eye microsystems such as smart contacts for vision correction, health monitoring, drug delivery, and displaying information represent a new emerging class of low‐profile (≤ 1 mm) wireless microsystems that conform to the curvature of the eyeball surface. The implementation of suitable low‐profile power sources for eye‐based microsystems on curved substrates is a major technical challenge addressed in this paper. The fabrication and characterization of a hybrid energy generation unit composed of a flexible silicon solar cell and eye‐blinking activated Mg–O2 metal–air harvester capable of sustainably supplying electrical power to smart ocular devices are reported. The encapsulated photovoltaic device provides a DC output with a power density of 42.4 µW cm−2 and 2.5 mW cm−2 under indoor and outdoor lighting conditions, respectively. The eye‐blinking activated Mg–air harvester delivers pulsed power output with a maximum power density of 1.3 mW cm−2. A power management circuit with an integrated 11 mF supercapacitor is used to convert the harvesters’ pulsed voltages to DC, boost up the voltages, and continuously deliver ≈150 µW at a stable 3.3 V DC output. Uniquely, in contrast to wireless power transfer, the power pack continuously generates electric power and does not require any type of external accessories for operation.

Smart Contact Lenses in Ophthalmology: Innovations, Applications, and Future Prospects

“…Triboelectric nanogenerators may have the potential to harness energy from the natural movements of the eyes such as blinking or normal eye movements, however, miniaturizing the manufacturing of such devices may be a challenge. Pourshaban et al (2024) designed an SCL that uses both solar power and a metal-air power harvester that is powered through blinking movements [54]. As the eyelid moves across the harvester, the electrolytes in tear fluid spark an oxidation reaction and produces electrons that power the SCL.…”