Miniaturization and modeling of a folded beam-based microelectromechanical intraocular pressure sensor

Abstract

This paper describes the design and detailed analysis of a microelectromechanical system (MEMS) capacitive pressure sensor consisting of nested folded beam suspensions and variously shaped diaphragms that can be used as a part of an LC tank implant circuit for biomedical pressure sensing applications, designed specifically for continuous intraocular pressure (IOP) monitoring in glaucoma patients. The pressure sensor has been designed to measure pressures within the IOP sensor range of 0–8000 Pa. This paper aims to reduce the size of the sensor in comparison to previous research. Significant benefits of miniaturization include requiring less energy, being lightweight, being inexpensive, and having minimal impact on the objects being detected. The MEMS implantable pressure sensor for continuous monitoring of IOP would prevent the progression of the disease, and these tiny devices could alleviate patients’ suffering. Microbeams are likely the most widely utilized structural element in MEMS. This design adds nested folded beam suspensions to the diaphragm, which reduces the diaphragm’s residual tension and rigidity; as a result, the device’s dimension is smaller than the diaphragm without flexible beams (previous work). Due to the reduced rigidity, nested folded beam suspensions can also enhance sensitivity. Finally, the central deflection of the diaphragm will be determined under uniform external pressure. Using COMSOL/Multiphysics and SolidWorks, the design and simulation of pressure sensors have been accomplished. The outcomes reveal that the capacitive pressure sensor with nested folded beam suspensions and the rectangular diaphragm is better suited for measuring IOP, and its dimensions are also smaller than those of previous works ().