Silver Nanowire-based Capacitive Type Pressure and Strain Sensors for Human Motion Monitoring

High-performance flexible and stretchable sensors, especially pressure and strain sensors, have shown promising approaches for human motion detection. Besides being skin-friendly and biocompatible, the required features for such types of sensors are being lightweight, flexible, and stretchable. Based on the working mechanism, these sensors could be categorized as capacitive, piezoresistive, and piezoelectric. Among these, capacitive type pressure and strain sensors have received great attention, owing to their simple structure, uncomplicated sensing mechanism, and low cost. Ordinarily, the capacitive sensor consists of two parallel-plate electrodes with a dielectric interlayer sandwiched in between. 1D metallic nanomaterials, such as silver nanowires, have demonstrated great potential as metallic electrodes in the mentioned sensors because of their low-cost, facile synthesis, tunable length/diameter, and solution-processable properties. Therefore, in this chapter, we review the recent advances in the fabrication of capacitive type pressure and strain sensors with silver nanowires. The methodologies and materials for obtaining such devices and the highlights of pressure and strain sensor features are also elaborated. Finally, the feasibility and the prospects of the field are discussed.