Evaluation of Carbon Nanotube-Based MEMS Piezoresistive Pressure Sensors

This paper presents the performance characteristics evaluation of a carbon nanotubes (CNTs) based MEMS pressure sensor with piezoresistive gauge factor, which is much greater than polysilicon based sensors. Polysilicon is a piezoresistive material used for MEMS sensor because of one of its advantages is that much higher sensitivity to strain changes than metals. Recently, Nanotechnology is introduced to produce this material. Using the dielectrophoretic (OEP) Nanoassembly of CNTs and a MEMS-compatible process, successfully integrated bundled strands of CNT sensing elements on arrays of Polymethylmethacrylate (PMMA) diaphragms. The piezoresistive effects of CNT were realized by measuring the pressure-resistance dependency of the sensor and results obtained showed that the CNT-based micro sensor is capable of sensing input pressure variations. The mechanical properties of the diaphragms are investigated theoretically. In this work, Matlab environment is employed to model this sensor and accurate model is devised to study its performance. Simulation results are obtained and compared with published experimental work and full argument is obtained. The proposed model allows handling different parameters affecting the performance of this sensor.