Multi-dimensional strain sensor based on carbon nanotube film with aligned conductive networks

Abstract Carbon nanotubes (CNTs) show a tremendous promise on strain sensor applications, but the stretchable ability of CNT devices is low due to their poor ductility. Herein, novel aligned conductive networks of CNT film were designed and introduced onto polydimethylsiloxane (PDMS) substrate, which realized highly stretchable multi-dimensional strain sensitivity up to a strain of 260% and an excellent cyclical durability. The gauge factor (GF) along the CNT aligned direction, i. e. A direction, can reach 461 up to a strain of 260% while the resistance of the perpendicular direction (B direction) keeps almost the same with initial value, showing a multi-dimensional strain detection capability. The high GF along A direction of the CNT film is caused by the slippage, damage and rupture of CNT bundles with strain increasing, while the CNT entanglement between the adjacent CNTs stabilizes the resistance along B direction. This study rationalizes the aligned CNT network concept to realize the multi-dimensional strain sensors, which have a great potential to be applied in complex strain detection in practical applications.