A Review on Silicon Nanowires and their Use in the Development of Nano Piezoresistive Pressure Sensors

Silicon has been the most trusted and used material in the fabrication of microelectronics components and systems. Recently, silicon nanowires have gained a lot of importance in the development of devices/components in many applications. SiNWs have unique attributes that are not found in bulk silicon. Their one-dimensional electronic structure provides interesting properties. Unique properties and small dimension (nm) of silicon nanowires have made them to be used as sensing elements in the development of nanosensors and devices. Silicon nanowires are now being extensively used in the development of biosensors, FETs, lithium-ion batteries, transistors, microelectronic chips, and sensors. SiNWs are used in the development of solar cells and photovoltaic batteries, because of their charge-trapping capabilities. The fabrication of silicon nanowires follows chemical etching, chemical vapor deposition (CVD), electron beam lithography, etc. The dimensions of silicon nanowires are highly compatible with the dimensions of biological and chemical species, hence making them more efficient to be used as sensing elements in bio and chemical domains. SiNWs exhibit excellent piezoresistive properties and hence are used as piezoresistors in piezoresistive sensing applications. This article presents a review of SiNWs in the development of sensors. An emphasis is given to the piezoresistive property of SiNWs. The use of SiNWs as a piezoresistor in the development of piezoresistive pressure sensors is also extensively reviewed in this article, along with the unique properties of SiNWs. Typical dimensions and applications of SiNWs are also reviewed. Moreover, this article also explores the fabrication, characterization aspects, and capabilities of SiNWs in the design and development of nanoscale devices/sensors.