Journal: Nature Communications

Article Title: Highly twisted supercoils for superelastic multi-functional fibres

doi: 10.1038/s41467-018-08016-w

Figure Lengend Snippet: Schematic illustration and morphological information of supercoiled fibres. a Schematic illustration of highly twisted spandex@carbon nanotube (CNT) fibre, consisting of first-coils and supercoils. Inset shows a schematic of microscale buckled surface. Scanning electron microscopy (SEM) images for b microscopic scaled buckles formed on the surface of spandex@CNT fibre relaxed from pre-strain (scale bar = 15 μm), and c its magnification showing uniaxially aligned CNT bundles (scale bar = 5 μm). SEM images for d noncoiled, e first coiled, and f supercoiled spandex@CNT fibres, showing subsequent structure transformations as the number of twists increases (scale bars for d , e , and f are 200 μm). Inset images from e and f show fibre transformations from noncoiled fibre into first coil, and from first coil into supercoil, respectively. The arrows indicate the propagation direction of coil formation. g Measured length-normalised resistance changes and fibre length contraction versus number of inserted twists until full supercoiling ( R(ε) is the resistance of fibre at the stretched state and L 0 is the length of fibre at the initial state). Photograph of h free-standing state, double-helix structured, supercoiled fibre, and optical images of i its magnification (scale bar = 1 mm), j 3.5-cm-long, six-woven supercoiled spandex@CNT fibres into a commercial mock rib-structured textile, and k 20 mm-long, 7 mm-wide supercoil textile consisting of 27 spandex@CNT fibres

Article Snippet: Multiwalled carbon nanotube (MWNT) sheets were mechanically drawn from a carbon nanotube (CNT) forest with 750-μm height (NTAD 10, PDSI Corporation, Korea) and were wrapped on a 200 μm-diameter commercially available spandex fibre (Hyosung, Korea).

Techniques: Electron Microscopy

Journal: Nature Communications

Article Title: Highly twisted supercoils for superelastic multi-functional fibres

doi: 10.1038/s41467-018-08016-w

Figure Lengend Snippet: Structural analysis of microscopic buckles and macroscopic supercoils. a Average width of microscopic carbon nanotube (CNT) buckles of noncoiled, relaxed spandex@CNT fibre versus applied pre-strain. Insets show scanning electron microscopy (SEM) images for CNT buckles formed from 100% (lower image) and 400% (upper image) pre-strains (scale bar = 20 μm). b Average buckle width and fibre contraction length ratio versus CNT loading layer. Inset shows SEM image of buckles formed from five layers CNT wrapping (scale bar = 50 μm). c Scheme showing various morphological parameters of supercoil fibre ( D is a diameter of coiled fibre, d is a diameter of spandex@CNT fibre, θʼ is a coil bias angle, D’ is a diameter of supercoiled fibre, and L is a length of supercoiled fibre). d Linear coil density ( 1/D ) and supercoil index ( D’/d ) versus total twisting number insertion for fully supercoiling. e Fibre aspect ratio ( L/D’ ), maximum stretchability, and resistance change during fibre maximum stretching versus total twisting number insertion for fully supercoiling ( R(ε) and R 0 is the resistance of fibre at stretched and initial state, respectively). Optical images showing supercoil fibres fabricated from f low twisting (4165 turns m -1 ), and g high twisting (10496 turns m -1 ) insertions (both scale bars = 300 μm). Insets show SEM images of magnified supercoil surfaces (both scale bars = 100 μm)

Article Snippet: Multiwalled carbon nanotube (MWNT) sheets were mechanically drawn from a carbon nanotube (CNT) forest with 750-μm height (NTAD 10, PDSI Corporation, Korea) and were wrapped on a 200 μm-diameter commercially available spandex fibre (Hyosung, Korea).

Techniques: Electron Microscopy

Journal: Nature Communications

Article Title: Highly twisted supercoils for superelastic multi-functional fibres

doi: 10.1038/s41467-018-08016-w

Figure Lengend Snippet: Passivated supercoiled fibre for high quality factor and transmission line applications. a Length-normalised resistance versus strain for styrene-ethylene-butylene-styrene (SEBS)-overcoated, spandex@carbon nanotube (CNT) supercoiled fibre. Inset shows the scheme for an SEBS-coated micro-buckle surface ( R(ε) is the resistance of fibre at the stretched state and L max is the length of fibre at the fully stretched state). b Amplitude of square wave voltage generated by functional generator ( f = 20 Hz) versus time recorded at initial, and 1000% strain application for pristine (up panel), and SEBS-coated (down panel) supercoiled fibres. c Quality factor (percent strain divided by percent resistance change) versus strain for spandex@SEBS/CNT supercoiled fibre ( Q = 238.8, green star), and comparison with previously reported fibre electrodes: (a) a sandwich-structured CNT/rubber fibre ( Q = 54) , (b) a buckled CNT/SEBS fibre ( Q = 65.1) , (c) a coiled CNT/nylon fibre ( Q = 0.1) , (d) a buckled, coiled CNT/rubber fibre ( Q = 1.8) , and (e) a CNT/elastomer polymer fibre ( Q = 1.6) . Inset shows retention performance versus average voltage amplitude for pristine (open circles), and SEBS-coated (solid circles) supercoiled fibres. Schematic illustrations and images of the measurement setup for d electrocardiogram (ECG), e audio, and f video signal transmissions using supercoil fibres (all supercoiled fibres were mounted on Vernier calipers for measurements). Resulting g ECG (consisting of P wave, QRS wave, and T wave), h audio, and i video signals transmitted by commercial cables (reference, black line), and supercoil fibres of nonstretched (red line), and 1000% stretched (green line) are compared

Article Snippet: Multiwalled carbon nanotube (MWNT) sheets were mechanically drawn from a carbon nanotube (CNT) forest with 750-μm height (NTAD 10, PDSI Corporation, Korea) and were wrapped on a 200 μm-diameter commercially available spandex fibre (Hyosung, Korea).

Techniques: Transmission Assay, Generated, Functional Assay, Comparison, Polymer

Journal: Nature Communications

Article Title: Highly twisted supercoils for superelastic multi-functional fibres

doi: 10.1038/s41467-018-08016-w

Figure Lengend Snippet: Electrochemical performance of solid gel electrolyte coated supercapacitor. a Cyclic voltammetry (CV) curves at 50 mV s -1 for various MnO 2 wt%. b Calculated MnO 2 areal loading density, and linear capacitances versus MnO 2 loading wt%. CV curves (from 10 to 100 mV s -1 ) of supercoil fibres with c 10.8 wt%, and d 17.7 wt% MnO 2 loadings. e Galvanostatic charge/discharge curves (current density from 25 to 100 µA cm -1 ) of supercapacitor (SC) 17.7 wt% MnO 2 loading. f Specific linear (blue diamond) and areal (black circle) capacitance values versus scan rate. g CV curves measured for the initial ( ε = 0%) and statically stretched states of the supercoil supercapacitor. h Capacitance retention performance versus tensile strain (inset shows capacitance retention versus cyclically applied stretching test). i Linear capacitances versus maximum strains of various fibre supercapacitors. The maximum linear capacitance ( C L = 21.7 mF cm -1 ) and stretchability ( ε = 1000%) for the present supercoil supercapacitor exceed (a) a coiled MnO 2 /carbon nanotube (CNT)/nylon fibre (5.4 mF cm -1 , 150%) , (b) a coiled MnO 2 /CNT/rubber fibre (4.8 mF cm -1 , 400%) , (c) a MnO 2 /CNT/rectangular rubber sandwich fibre (2.38 mF cm -1 , 200%) , (d) a polyaniline (PANI)/CNT/elastomer fibre (0.9 mF cm -1 , 400%) , (e) a spandex@CNT-based wire SC (0.26 mF cm -1 , 100%) , and (f) a styrene-ethylene-butylene-styrene (SEBS) wounded by CNT/graphene/PANI fibres (10.3 mF cm -1 , 800%)

Article Snippet: Multiwalled carbon nanotube (MWNT) sheets were mechanically drawn from a carbon nanotube (CNT) forest with 750-μm height (NTAD 10, PDSI Corporation, Korea) and were wrapped on a 200 μm-diameter commercially available spandex fibre (Hyosung, Korea).

Techniques: