Design of MEMS Based High Sensitivity and Fast Response Capacitive Humidity Sensor

R. Karthick, S. P. K. Babu, A. R. Abirami, and S. Kalainila
Periyar Maniammai University
Periyar Nagar
Vallam, Thanjavur
Tamilnadu, India

This paper presents the design and simulation of high sensitivity and fast response capacitive humidity sensor. Generally, the capacitive humidity sensor is made up of parallel electrode, the upper electrode being a grid with various line width and line spacing.

A model is simulated using COMSOL Multiphysics. High sensitivity and fast response of the model is optimized by varying the thickness of the upper electrode and spacing between the electrodes. As an application example, this model may be used in the application of medicine and also to predict the process uncertainties in fabrication.

The structure is optimized for faster response time by varying upper electrode, smaller the upper electrode structure faster response time. Optimization is also done for higher sensitivity which shows sensitivity is higher for the structure whose upper electrode width is twice the spacing between the electrodes.