Wearable and Hybrid Power Sources for Smart Contact Lenses

A smart contact lens can be used as a prospective interface between the human eyes and electronic devices for wearable applications. However, the issue of power sources is an essential technical barricade for the large-scale commercialization of smart contact lenses. Here, a hybrid power source using glucose/O
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biofuel cell (BFC) and zinc/O
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primary battery (PB) for contact lenses has been demonstrated (Figure 1). The biofuel cell was consisted of a glucose oxidase (GOD)/osmium-based mediator/polyethylenedioxythiophene (PEDOT): carbon nanotube (CNT)/gold wire bioanode for glucose oxidation and a bilirubin oxidase (BOD)/PEDOT: CNT/gold wire biocathode for oxygen reduction. The primary battery was consisted of a zinc/gold wire anode for zinc oxidation and a BOD/PEDOT: CNT/gold wire biocathode for oxygen reduction. The performances of both BFC and PB are 7.84 μW at 0.28 V and 20.61 μW at 0.64 V, respectively. The hybrid cells generate a power of 32.46 μW at a voltage of 0.47 V, indicating a 112% enhancement of the power source performance. Furthermore, when we mount the power sources on the lens, the visible light passes through the lens at 80% transmittance. The present hybrid power sources provide a potential solution for powering smart contact lenses in the future.