Ionic liquid enabled electrical-strain tuning capability of carbon black based conductive polymer composites for small-strain sensors and stretchable conductors

Conductive carbon black (CB) filled styrene-butadiene rubber composites with tuneable electrical-strain behaviour were prepared based on the use of ionic liquid (IL). The addition of IL is also capable of improving electrical conductivity and flexibility, thus, enabling use in applications such as small-strain sensors and stretchable conductors. For small-strain sensors, at small strains up to 9%, the composite with IL/CB ratio of 1.5 gives sensitivity up to about 700% higher than that without IL. Also, the sensing consistency is enhanced with increased IL/CB ratios. For stretchable conductors, the use of IL makes the alignment of the aggregate more effective, thus allowing an extension of the maximum conducting strain. This can be extended from less than 40% to approximately 180% using an IL/CB ratio of 1.5 in combination with an adjusted mixing time.