Characterization of screen-printed silver nanowire (AgNW)-based soft strain sensors

The exceptional electrical conductivity and flexibility of silver nanowires (AgNWs) have gained significant interest within the wearable sensor applications. The utilization of AgNWs conductive channels offers a potential economically viable strategy for the advancement of flexible and stretchable electronics, which possess unique attributes as strain sensors. The width of these conductive channels has a crucial role in determining the distribution of AgNWs, which in turn has the ability to affect the performance of sensors. The objective of this study is to investigate the impact of open channel width on the dispersion of printed AgNWs and its subsequent impacts on the electrical characteristics of strain sensors. Polydimethylsiloxane (PDMS) is selected as the material for molds and substrates owing to its inherent stretchability, making it a popular choice for the fabrication of flexible and/or stretchable sensors. Laser cutting technique was employed to produce the screen-printing mold with a range of channel widths. Then strain sensors were fabricated by printing AgNW suspensions through the mold, and analyzed their resulting electrical properties. This study encompassed the measurement of gauge parameters in order to evaluate sensitivity, the analysis of linearity and hysteresis to assess response consistency. Finally, based on the sensitivity required for sensing the gesture motion on the hand, we select strain sensors with appropriate widths of AgNWs to attach to the hand in order to detect finger or hand gestures to show its potential application as wearable electronics.