Design and Simulation of Silicon Nanowire based Nano Capacitive Pressure Sensor

Abstract

This paper presents a nano capacitive pressure sensor with enhanced sensitivity using silicon nanowires. The work presented here reports the design and simulation of nanowire based capacitive pressure sensor for human blood pressure measurement. Usually ordinary circulatory pressure of a human is 120/80 mmHg. This range can deviate if a person has hypertension or any other medical issues. Hence this pressure measurement is a very first thing that is done before any diagnosis or treatment. Many conventional devices exist to measure the pressure and also digital devices are now being commercialized for measurement. The accuracy with which these digital devices function is always a concern. In this paper we present a nanowire-based cap active pressure sensor which can operate efficiently over the pressure range of 0 to 300 mmHg. A equivalent pressure of around 40kPa pressure is applied on the sensor for measurement and the sensor shows a good sensitivity of 2.5 X 10-6 pF/kPa. Keywords-MEMS, sensor, pressure sensor, nanowire, capacitive pressure sensor. I. INTRODUCTION Nanotechnology is a very rapidly growing technology for development of nano sized sensors and actuators. There is a lot of works reported on MEMS based pressure sensors. Capacitive pressure sensors are well suited for low pressure sensing applications. Works in [1][2][3][4][5] describes the development and analyses of MEMS based capacitive pressure sensors. Silicon nano wire based capacitive pressure sensors are gaining high attentions because of their small dimensions and better sensitivity. Nano sensors are probably going to affect our economy and society a lot and the technology, practically identical to that of semiconductor innovation [6]. The nanowire is largely suitable development of biosensor/biomedical sensors as, the properties of silicon nanowires depicts that they are mechanically, electrically stable [7]. Silicon nanowires-based transistors are developed by authors in [8]. Silicon nanowires are largely used for biomedical sensing applications, one such example, were the sensor was developed for carotid blood pressure of horses [9][10]. Currently, most common disease is high blood pressure. This can be detected using miniature pressure sensors [11][12]. A micron sized capacitive pressure sensor with 3μm electrode spacing was developed by authors [13]. Other applications were nanowire sensors are used are intraocular pressure, intracranial pressure measurements were mostly short-term measurements. For long term implantable pressure