Superelastic conducting fibers with improved properties and functionalities are needed for diverse applications. Here we report the fabrication of highly stretchable (up to 1320%) sheath-core conducting fibers created by wrapping carbon nanotube sheets oriented in the fiber direction on stretched rubber fiber cores. The resulting structure exhibited distinct short- and long-period sheath buckling that occurred reversibly out of phase in the axial and belt directions, enabling a resistance change of less than 5% for a 1000% stretch. By including other rubber and carbon nanotube sheath layers, we demonstrated strain sensors generating an 860% capacitance change and electrically powered torsional muscles operating reversibly by a coupled tension-to-torsion actuation mechanism. Using theory, we quantitatively explain the complementary effects of an increase in muscle length and a large positive Poisson's ratio on torsional actuation and electronic properties.

Monolayers of a new series of amide‐containing alkanethiol compounds, CH3(CH2)n‐2C(O)NHC2H4SH (referred as CnC2SH, n=4, 5, 5, 8), were self‐assembled from ethanol solutions onto gold and their structures have been characterized using the reflectance absorption infrared spectroscopy (RA‐FTIR) and wettability measurement. It has been proved that the CO and N‐H bonds are parallel to the gold surface and the orientations of alkyl chain in these Self‐Assembled Monolayers (SAMs) are perpendicular to the surface. The special orientation of the amide moiety and molecular axis are suggested to be attributed to the hydrogen‐bonding formed between the amide moieties of neighbor molecules. Meanwhile, wettability measurement reveals that the packing degree of the SAMs depends on the length of the alkyl chains in the thiol molecules. These results demonstrate that both the hydrogen‐bonding and the length of the alkyl chain exerts the tremendous influnece on the orientation of amide‐containing alkanethiol molecules. And also, it give us a way to control the molecular orientation in SAMs in molecular level.