Wearable strain sensors fabricated by silver nanowire patterning method based on parylene stencil technique

This paper describes a fabrication method of the silver nanowire (AgNW) patterns on PDMS substrate using a parylene stencil technique. The AgNW electrodes with the straight line and serpentine line traces were fabricated and characterized in terms of electromechanical properties. The sensitivity of the AgNW patterns was measured using a custom-designed stretch test module, resulting in gauge factors from 55.2 to 2.7 at 2% strain for two different 100 um-wide AgNW patterns. The wearable sensor based on AgNW patterns was designed and fabricated to epidermally detect the respiration and heart rate from the abdomen and neck. The respiration was continuously recorded for 10 min successfully. The heart rate from the carotid artery was also recorded without applying external pressure.