Design of Water Pressure Sensor Applied to the Eye Aqueous Humor Detection

Abstract

Aimed at the dynamic pressure measurement, this paper presents a pressure sensor based on MEMS technology. An absolute pressure sensor is in one silicon chip of which the size is 3.05mm×3.05mm with the diaphragm thickness of 890μm. We combine Piezoresistive Bridge with signal conditioning chip, and design a gain adjustable, high sensitivity dynamic pressure sensors. By changing the depth of the sensor in water, the resulting change in the resistor signal is then used to calculate the depth of the water. The experimental results show that the measuring accuracy can reach 2×10-4V per 1mm (water depth). The design of the hardware circuit was simple, flexible configuration, versatile features. It was found that the pressure sensor bad a linear response to pressure as expected, and was more sensitive than conventional resistor sensor. Sensor, small size, high sensitivity, will be providing a better way to measure eye aqueous humor.