Designed Electroosmotic Polymer for an Anti-Drying Contact Lens Device

摘要

A smart contact lens (CL) is an attractive wearable device that could enable noninvasive monitoring of physiological information and augmented reality display in addition to vision correction. Whereas, the CL is one of the causes of dry eye syndrome due to more rapid moisture evaporation through the CLs than that from the normal tear film covered by a lipid layer. Conventional rehydration by regular eye drops takes time and efforts. The only example so far of a smart CL for maintaining the moisture is that of Lee et al., who developed a CL coated with single layer of graphene which decreases the evaporation. Hence, there is still a high demand to develop a CL equipped with an anti-dehydration function. We here designed a charge-fixed soft CL generating electroosmotic flow (EOF) under an electric field for maintaining the moisture of the lens (Figure 1a). The CL supplies tears via EOF from the tear meniscus (temporary tear reservoir) behind the lower eyelid. EOF is the motion of water induced by an applied electric field across a fluid conduit like a capillary tube or a porous material such as hydrogels. When the fluid conduit contains fixed electrical charges, the dominant electromigration of the mobile counter ions produces net water flow.