Origami patterns, including the rigid origami patterns in which flat inflexible sheets are joined by creases, are primarily created for zero-thickness sheets. In order to apply them to fold structures such as roofs, solar panels, and space mirrors, for which thickness cannot be disregarded, various methods have been suggested. However, they generally involve adding materials to or offsetting panels away from the idealized sheet without altering the kinematic model used to simulate folding. We develop a comprehensive kinematic synthesis for rigid origami of thick panels that differs from the existing kinematic model but is capable of reproducing motions identical to that of zero-thickness origami. The approach, proven to be effective for typical origami, can be readily applied to fold real engineering structures.

Field emission data from aligned high-density carbon nanotubes (CNTs) with orientations parallel, 45°, and perpendicular to the substrate have been obtained. The large-area uniformly distributed CNTs were synthesized on smooth nickel substrates via dc plasma-assisted hot filament chemical vapor deposition. CNTs with diameters in the range of 100–200 nm were employed in this study. The different orientations were obtained by changing the angle between the substrate and the electrical field direction. The growth mechanism for the alignment and orientation control of CNTs has been discussed. The CNTs oriented parallel to the substrate have a lower onset applied field than those oriented perpendicular to the substrate. This result indicates that electrons can emit from the body of the CNT, which means that the CNT can be used as a linear emitter. The small radius of the tube wall and the existence of defects are suggested as the reasons for the emission of electrons from the body of the tubes.

The introduction of Prussian blue (PB), an inexpensive pigment material, elegantly breaks the solubility limit of the [Fe(CN) 6 ] 4À/3À electrolyte, and substantially boosts the capacity via an off-electrode chemical reaction. In the reversible redoxtargeting reaction cycles, PB acts as the energy reservoir, while [Fe(CN) 6 ] 4À/3À plays a role in mediating the reactions between the electrode and storage tank. The volumetric capacity surpasses other reported [Fe(CN) 6 ] 4À/3À -based and most other organic aqueous redox flow batteries.

Flexible lithium batteries with high energy density have recently received tremendous interest due to their potential applications in flexible electronic devices. Herein, we report a novel method to fabricate highly flexible and robust carbon nanotube–graphene/sulfur (CNTs–RGO/S) composite film as free-standing cathode for flexible Li/S batteries with increased capacity and significantly improved rate capability. The free-standing CNTs–RGO/S cathode was able to deliver a peak capacity of 911.5 mAh g–1 sulfur (∼483 mAh g–1 electrode) and maintain 771.8 mAh g–1 sulfur after 100 charge–discharge cycles at 0.2C, indicating a capacity retention of 84.7%, which were both higher than the cathodes assembled without CNTs. Even after 100 cycles, the cathode showed a high tensile strength of 62.3 MPa. More importantly, the rate capability was improved by introducing CNTs. The CNTs–RGO/S cathode exhibited impressive capacities of 613.1 mAh g–1 sulfur at 1C with a capacity recuperability of ∼94% as the current returned to 0.2C. These results demonstrate that the well-designed nanocomposites are of great potential as the cathode for flexible lithium sulfur (Li/S) batteries. Such improved electrochemical properties could be attributed to the unique coaxial architecture of the nanocomposite, in which the evenly dispersed CNTs enable electrodes with improved electrical conductivity and mechanical properties and better ability to avoid the aggregation and ensure the dispersive distribution of the sulfur species during the charge/discharge process.