Self-moisturizing contact lens employing capillary flow

In spite of the great promise that contact lenses offer from vision correction to wearable sensing technologies, wearing contact lens often reported to result in dry eye problems and associated inflammation or corneal wound. To mitigate these health concerns, strategies to keep the lens moisturized by maintaining a tear film have currently been explored. Herein, we demonstrate the utility of the well-known capillary rise in microchannels embedded in the contact lens via soft-lithographic replication of a master structure manufactured by the 3D-additive manufacturing technique. The inherently considered drawback of the 3D printing technique, the staircase effect occurs during the layer-wise building of the master structure and produces microcapillaries in a replicated polydimethylsiloxane contact lens. These microcapillaries facilitate the capillary rise through the channels to maintain a moisturized contact lens. The capability of fabricating curved microchannels and polishing the optical zone results in a self-moisturized contact lens with high optical transmittance for the pupil region. The technique adopted here is free from the usage of any external driving sources and complicated nanostructure fabrication onto the biocompatible contact lens and thus offers the possibility of easy adoption with the existing fabrication techniques.