Performance enhancement by implementation of nanostructure sensing element for bendable SAW gas sensor: Simulation

Abstract

Flexible technology is current promising area in electronics devices and sensors. There are several advantages such as lightweight, low cost and mechanically flexible which attract the market growth. A rigid Surface Acoustic Wave (SAW) gas sensor that conventionally fabricated on crystals or thin film on substrates is less suitable for uneven surfaces. In addition the interest of applying nanostructure as sensing element has emerged to amplify the performance of the sensors. This study presents comparisons simulation on basic Surface Acoustic Wave (SAW) gas sensor and also the enhanced version by employing nanostructure as a sensitive layer on flexible substrate using COMSOL multiphysics. For the first part, simulation on the sensing element was in thin film form. Next, nanowires were designed and stacked on top of the Inter Digitated Transducer (IDTs), so that it will improve the sensitivity of the gas sensor. In both parts, simulation were done in three different model design condition namely flat, bend in and bend out. The main objective is to investigate the effect of implementing nanostructure as sensing element. The results show increase in sensitivity of the sensor up to 9179.8 kHz/kgm–3 and maximum frequency shift of 91.9 Hz after implementing nanostructured.