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It is shown that the dominant conduction mechanism in single-wall carbon nanotube networks at room temperature is variable range hopping. Thin networks follow a variable range hopping law throughout the temperature range 4 K < T < 300 K, thick networks display variable range hopping characteristics in the range 50 K < T < 300 K, with deviation to Bloch–Gruneisen behaviour at lower temperatures. The adsorption state of these materials is shown to determine the sign of change in conductance upon subsequent exposure to oxygen. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The development of new flexible and stretchable sensors addresses the demands of upcoming application fields like internet-of-things, soft robotics, and health/structure monitoring. However, finding a reliable and robust power source to operate these devices, particularly in off-the-grid, maintenance-free applications, still poses a great challenge. The exploitation of ubiquitous temperature gradients, as the source of energy, can become a practical solution, since the recent discovery of the outstanding thermoelectric properties of a conductive polymer, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS). Unfortunately the use of PEDOT:PSS is currently constrained by its brittleness and limited processability. Herein, PEDOT:PSS is blended with a commercial elastomeric polyurethane (Lycra), to obtain tough and processable self-standing films. A remarkable strain-at-break of ≈700% is achieved for blends with 90 wt% Lycra, after ethylene glycol treatment, without affecting the Seebeck voltage. For the first time the viability of these novel blends as stretchable self-powered sensors is demonstrated.

A facile chemical vapor deposition-based method for the texturing of substrate-supported iron-filled multiwalled carbon nanotube arrays is reported. The method is based on the interplay of temperature gradients and modulated vapor flow that produces annular height variation and a vertical-array-to-spherulitic morphological transformation in experimental conditions, which result in uniform, close-packed arrays of constant height in an unmodulated vapor flow. These observations are proposed to result from creation of stationary cells of feedstock vapor above the growth front.

Corrected values for the coefficients G0 and T0 in Table 2 as well as the corrected value for the parameter T0 in Eq. (3) are given for the paper by Morgan et al. [Phys. Status Solidi A 205, No. 6, 1394–1398 (2008)]. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)