Highly sensitive strain sensor based on stretchable sandwich-type composite of carbon nanotube and poly(styrene-butadiene-styrene)

A highly flexible, stretchable, and sensitive strain sensor based on sandwich-type composite of carbon nanotube (CNT) and poly(styrene-butadiene-styrene) was synthesized. The composite films were characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy. Stress-strain measurements with simultaneous electrical detection were performed to investigate the electromechanical response of the composite films. Result shows that the sandwich-type composite exhibits better response than normal blended ones. In particular, the sandwich-like composite with optimal CNT content (5 wt% in an intermediate layer) has a wide workable strain range (approximately 170 %), high sensitivity (e.g., gauge factor of 260 at 50 % strain and 1734 at 100 % strain), and long-term durability. The response mechanism of the sandwich-type composite was also discussed, and its high sensitivity and good stability indicate its promising application. (C) 2020 Elsevier B.V. All rights reserved.