Apparatuses for manipulating a color displayed by an article of wear comprising iron oxide colloidal nanocrystals arranged within chains are described. The apparatus includes (a) a magnetic field source, wherein a strength of a magnetic field generated by the magnetic field source is tunable to control the color displayed by the article of wear, and (b) an energy source, wherein energy generated by the energy source is applied to at least some of the chains of nanocrystals to soften materials within the article of wear immediately surrounding the chains of nanocrystals to which the energy is applied.

The present invention is directed to nanofiber yarns, ribbons, and sheets; to methods of making said yarns, ribbons, and sheets; and to applications of said yarns, ribbons, and sheets. In some embodiments, the nanotube yarns, ribbons, and sheets comprise carbon nanotubes. Particularly, such carbon nanotube yarns of the present invention provide unique properties and property combinations such as extreme toughness, resistance to failure at knots, high electrical and thermal conductivities, high absorption of energy that occurs reversibly, up to 13% strain-to-failure compared with the few percent strain-to-failure of other fibers with similar toughness, very high resistance to creep, retention of strength even when heated in air at 450 C. for one hour, and very high radiation and UV resistance, even when irradiated in air. Furthermore these nanotube yarns can be spun as one micron diameter yarns and plied at will to make two-fold, four-fold, and higher fold yarns. Additional embodiments provide for the spinning of nanofiber sheets having arbitrarily large widths. In still additional embodiments, the present invention is directed to applications and devices that utilize and/or comprise the nanofiber yarns, ribbons, and sheets of the present invention.

A nanofiber forest on a substrate can be patterned to produce a patterned assembly of nanofibers that can be drawn to form nanofiber sheets, ribbons, or yarns.

A nanofiber forest on a substrate can be patterned to produce a patterned assembly of nanofibers that can be drawn to form nanofiber sheets, ribbons, or yarns.

The present invention relates to a process for producing a carbon nanotube-grafted substrate, the process comprising: providing a substrate having catalytic material deposited thereon; and synthesising carbon nanotubes on the substrate by a chemical vapour deposition process in a reaction chamber; characterised in that the process comprises providing a counter electrode, applying a potential difference to the substrate in relation to the counter electrode and maintaining the potential difference of the substrate in relation to the counter electrode during the chemical vapour deposition process.

A process of producing a yarn, ribbon or sheet comprising nanofibers that includes infiltrating a liquid into the yarn, ribbon or sheet and evaporating the liquid from the yarn, ribbon, or sheet to strengthen the yarn, ribbon or sheet. The yarn, ribbon, or sheet can be formed by solid-state draw from a carbon nanotube forest.

Fabricating a nanofiber sheet, ribbon, or yarn by a continuous process that includes synthesizing a nanofiber forest in a furnace growth region on a substrate, wherein the nanofiber forest comprises a parallel array of nanofibers, and further includes drawing said nanofibers from the nanofiber forest to form a primary assembly that is the sheet, ribbon or yarn. The substrate continuously moves from the furnace growth region into a region where the nanofibers in the forest are drawn.

A device including an array of aligned conductive channels. The conductive channels are operable for directional transport of species selected from the group consisting of electrons, ions, phonons, and combinations thereof. The conductive channels are provided for by nanofibers in a form selected from the group consisting of ribbons, sheets, yarns, and combinations thereof.

An electric machine may include at least one stator and at least one rotor mounted to rotate relative to the stator, the stator and/or the rotor including at least one electrically conductive conductor winding, wherein at least some sections of the at least one electrically conductive conductor winding are formed from nano-scale carbon structures combined into at least one textile structure, or include nano-scale carbon structures combined into at least one textile structure.

A process of producing a yarn, ribbon or sheet that includes nanofibers in which the process includes forming a yarn, ribbon or sheet comprising nanofibers, and applying an enhancing agent comprising a polymer to the yarn, ribbon or sheet.