Twistable and Stretchable Sandwich Structured Fiber for Wearable Sensors and Supercapacitors

Twistable and stretchable fiber-based electrochemical devices having high performance are needed for future applications, including emerging wearable electronics. Weavable fiber redox supercapacitors and strain sensors are here introduced, which comprise a dielectric layer sandwiched between functionalized buckled carbon nanotube electrodes. On the macroscopic scale, the sandwiched core rubber of the fiber acts as a dielectric layer for capacitive strain sensing and as an elastomeric substrate that prevents electrical shorting and irreversible structural changes during severe mechanical deformations. On the microscopic scale, the buckled CNT electrodes effectively absorb tensile or shear stresses, providing an essentially constant electrical conductance. Consequently, the sandwich fibers provide the dual functions of (1) strain sensing, by generating approximately 115.7% and 26% capacitance changes during stretching (200%) and giant twist (1700 rad.m(-1) or 270 turns.m(-1)), respectively, and (2) electrochemical energy storage, providing high linear and areal capacitances (2.38 mF.cm(-1) and 11.88 mF.cm(-2)) and retention of more than 95% of initial energy storage capability under large mechanical deformations

Rational design of galvanically replaced Pt-anchored electrospun WO3 nanofibers as efficient electrode materials for methanol oxidation

<p>We develop a simple dry wrapping method to fabricate a tungsten oxide (WO_{<font size="2">3</font>})/carbon nanotube (CNT) cable, in which WO_{<font size="2">3</font>} layers act as an electrochromic component while aligned CNTs as the core provide mechanical support and an anisotropic, continuous electron transport pathway. Interestingly, the resultant cable material exhibits an obvious gradient electrochromic phenomenon.</p><br /

Architecting Three-Dimensional Networks in Carbon Nanotube Buckypapers for Thermal Interface Materials

<p class="articleBody_abstractText">Carbon nanotube (CNT) buckypaper, which has large specific surface area and tunable network structures, shows great potential in the application of heat dissipation for high power electronic devices. In this article, we report that the heat conduction in a buckypaper depends greatly on CNT network formation, in which CNT structures, lengths, and orientations are important issues. The buckypaper composed of multiwalled CNTs with large diameter (around 50 nm) and suitable length (1&ndash;10 &mu;m) shows lower thermal impedance compared with those made by longer CNTs with smaller diameter. The thermal impedance of such buckypapers can be reduced to 0.27 cm²&middot;K/W, lower than that of commercialized graphite foil and thermal grease. Thus, the buckypaper may serve as a promising candidate for advanced thermal interface materials. Detailed structural characterization indicates that the three-dimensional networks of buckypapers, with CNT orientations perpendicular to the surfaces, result in both the reduction of thermal contact resistance and the enhancement of heat conduction along the thickness.</p