Research On Tunable Metamaterial Device Used In Intraocular Pressure Monitoring

Glaucoma is the second cause of blindness. It affects one in100individualsworldwide. Intraocular pressure (IOP) is the main risk factor in the pathogenesisof glaucoma, and is the primary indicative factor in the diagnosis andmanagement of glaucoma. But measurements from a single visit to the clinicmiss the peak IOP that may occur at night during sleep, and ophthalmologistcan’t understand the development and progression of the disease accurately. Sowe need some miniaturized medical equipments which can be used for24-hcontinuous IOP monitoring. Metamaterial is an artificial electromagnetic materialthat consisted of unit structure with period arrangement. Due to specialelectromagnetic properties different from common natural material, metamaterialhas huge potential value in detectors and sensors. In this paper，according to theeye tissue (cornea and sclera) and contact lens will deform when the IOPchanged, we designed tunable MEMS metamaterial devices which expected to beuse for IOP monitoring.Firstly, we modeled the eye tissue (cornea and sclera) and contact lens byCOMSOL Multiphysics, simulated their total deformation loaded by elevatedIOP, and analyzed the effects of different structure and physical parameter.After that, we proposed a new method to monitor IOP by utilizing photoniccrystals. We fabricated flow-focusing microfluidic chip for droplet generation bymeans of MEMS process, and used it to produce three-dimensional photoniccrystals. We experimented the discoloration effect of three-dimensional photoniccrystals under external force.At last, we present the design and numerical simulations of a dual bandMEMS tunable terahertz(THz) metamaterial absorber. The designed absorberconsists of a metallic ground fixed on substrate and a movable metallicresonators arrarys suspended above the ground. We calculated surface currentdistribution and power flow distribution respectively, the results show that the four L-shaped resonators worked at2.44THz and the cross-shaped resonatorworked at3.712THz. If we changed the absorber substrate into flexible material,we could control the displacement between metallic resonators and metallicground under press, realized pressure sensing. This device is potentially appliedto IOP monitoring.