Notched-ring structured microfluidic contact lens for intraocular pressure monitoring

Microfluidic contact lenses (MCLs) for continuous intraocular pressure (IOP) monitoring are promising devices for the diagnosis and management of glaucoma. Here, we present an ultra-sensitive and cost-effective MCL for IOP monitoring. A folding method that allows 2D-to-3D transformation of a planar microchannel is introduced. An ultra-sensitive serpentine microchannel of notched-ring configuration is designed in coordination with the folding method. The optimization of the microchannel geometry is performed through numerical simulations and experiments. The performance of the device is evaluated using a hemispherical silicone model eye. The sensitivity of the MCL reaches up to 0.825°/μl, which clearly exceeds the existing MCLs. Moreover, stair-case and cyclical tests are performed to confirm the device's recoverability and repeatability. These results prove that the proposed MCL is a suitable selection for intraocular pressure monitoring.