High resolution screen-printing of carbon black/carbon nanotube composite for stretchable and wearable strain sensor with controllable sensitivity

With the growing trend of accelerating sensor miniaturization, high-resolution printing technology of stretchable sensors is becoming increasingly important. In this study, we demonstrated stretchable strain sensor with various line resolutions from 50 to 500 μm based on CB/CNT composite using screen printing process for human motion detection. To optimize composite formula, we systematically investigated rheological properties of the composites, resulting in realization of screen printed pattens with 50–500 μm of line width; and also investigated the relation among printed line width, resistance, conductivity, and line thickness. The printed pattern elastic strain sensor exhibited a controllable gauge factor (G.F.) such as 2.6 at 5% strain and 4.1 at 50% strain for linewidths of 50 and 500 μm, respectively, for accurate human motion detection and stable performance was also detected for 300 bending tests. From the result of this study, we proved that the printed pattern can be a potential stretchable strain sensor with controllable sensitivity and high resistance to temperature change.