Super‐Stretchable Spring‐Like Carbon Nanotube Ropes

Abstract

Spring-like carbon nanotube ropes consisting of perfectly arranged loops are fabricated by spinning single-walled nanotube films, and can sustain tensile strains as high as 285%.

A highly stretchable, helical copper nanowire conductor exhibiting a stretchability of 700%

“…Spring-like carbon nanotube yarn-shaped conductors with a high stretchability of up to 285% were previously reported. 33 In this study, we describe a novel, highly stretchable and reversible, helicalstructured CuNW network conductor with significantly improved mechanical and electrical properties.…”

Elastomeric and Dynamic MnO2/CNT Core–Shell Structure Coiled Yarn Supercapacitor

“…Although the theoretical maximum strain is much higher for coiled CNT yarn (about more than 300% strain, which originates from the relation L(coiled yarn length)  l(initial yarn length)/), 29 we present 37.5% as the maximum strain for a coiled supercapacitor. Because the applied strain rate for static tests in this study is much faster (180 mm min -1 or 2% s -1 ) than the literature 29 (0.5 mm min -1 strain rate, 15 minute intermediate stress relaxation every strain increment) that not enough relaxation time is provided to uniformly relax the generated internal stresses during stretching and this results in early fracture for the coiled yarn (~40% in tensile strain). In spite of such an early fracture, we adopted high strain rates (2-6% s -1 or 180-540 mm min -1 for dynamic tests) based stretching tests to reflect the real circumstances of wearable applications.…”

“…[19][20][21][22][23][24] In addition, the constant slopes of the loading curves exhibit high modulus from 290 ( = 20%) to 325 MPa ( = 40%), while hysteretic energy dissipations by the recovery friction force were observed during unloading. 29 The capacitance retention of the coiled supercapacitor under mechanically static strain (2% s -1 ) is characterized by comparing its CV curves before and after 37.5% strain was applied, as shown in Figure 4C. Figure 4D shows static capacitance retention with a strain range from 20% to 40% before the coiled yarn breaks.…”

“…This capacitance drop can be attributed to a linear resistance increase of the coiled electrode when it gets stretched. 29 The inset shows SEM images of microloops before and after 37.5% stretching, showing reversible intercoil distance change.…”

Elastic properties of single-walled carbon nanotube clusters: Dependence on hydrostatic pressure

“…However, to obtain a balanced combination of mechanical and electrical properties of CNTs for some specific applications, it is often desirable to synthesize CNT arrays with a parallel axis to form a cluster of a honeycomb-like structure [2]. These include their applications as springs [3], field emission displays [4], energy storage [5] and electrical interconnection [6]. A CNT cluster has a two dimensional triangular lattice constant, and has a plane of symmetry.…”