Abstract: An apparatus and method for transferring nanofiber structures (e.g., nanofiber films, nanofiber sheets, stacks of nanofiber grids, nanofiber films, nanofiber sheets, and combinations thereof) between various substrates are described. The techniques described use a soluble layer on a substrate that is subsequently dissolved, thus freeing the nanofiber structure from the substrate. This liquid phase techniques preserves the mechanical integrity and the purity of the nanofiber structures.

Abstract: An insulated nanofiber having a continuous nanofiber collection extending along a longitudinal axis with an outside surface and an inside portion is described. A first material infiltrates the inside portion, where the outside surface of the nanofiber collection is substantially free of the first material. An electrically-insulating second material coats the outside surface of the nanofiber collection. A method of making an insulated nanofiber collection is also disclosed.

Abstract: Actuators (artificial muscles) comprising twisted polymer fibers generate tensile actuation when powered thermally. In some embodiments, the thermally-powered polymer fiber tensile actuator can be incorporated into an article, such as a textile or garment.

Abstract: An array of discrete nanofiber films that are physically separated from one another are described. Techniques for forming the nanofiber film array are also described. Techniques for forming these structures include placing a suspension of nanofibers and/or nanoparticles on a patterned substrate. A pressure differential is applied, drawing the solvent of the suspension through holes in a mask. The nanofibers collect on an impermeable layer on the mask in a pattern corresponding to the negative features (grooves, holes, trenches) of the mask as the solvent is flowed through the holes.

Abstract: Techniques are disclosed for producing multilayered composites of adhesive nanofiber composites. Specifically, one or more sheets of highly aligned nanofibers are partially embedded in an adhesive such that at least a portion of the nanofiber sheet is free from adhesive and is available to conduct current with adjacent electrical features. In some example embodiments, the adhesive nanofiber composites are metallized with a conductive metal and in these and other embodiments, the adhesive nanofiber composites may also be stretchable.

Abstract: A density of a nanofiber sheet can be changed using an edged surface, and in particular an arcuate edged surface. As described herein, a nanofiber sheet is drawn over (and in contact with) an arcuate edged surface. Depending on whether the arcuate surface facing a direction opposite the direction in which the nanofiber sheet is being drawn is convex or concave determines whether the nanofiber sheet density is increased relative to the as-drawn sheet or decreased relative to the as-drawn sheet.

Abstract: Nanofiber membranes are described that include multiple layers of nanofiber structures, where each structure is a composite composition of multiwall carbon nanotubes and one or both of single wall and/or few walled carbon nanotubes. By selecting the relative proportions of multiwall and one or more of single/few wall carbon nanotubes in a nanofiber film, the membrane can be fabricated to withstand the heating that occurs during operation in an EUV lithography machine, while also having enough mechanical integrity to withstand pressure changes of between 1 atmosphere (atm) and 2 atm between operating cycles of an EUV lithography machine.

Abstract: A nanofiber yarn placement system includes a yarn dispenser assembly, and a placement assembly. The placement assembly includes a compliant flange, and a guide connected to the compliant flange. The guide defining a channel. The channel includes at least one internal surface and at least one corner defined by the at least one internal surface.

Abstract: Placement of nanofibers and yarns comprised of nanofibers onto a substrate are described. The nanofiber yarns are difficult to manipulate with precision given that the diameters can be as little as 5 microns or even less than one micron. As described herein, a placement system is described that can place nanofiber yarns on a substrate at pitches less than 100 ?m, less than 50 ?m, less than 10 ?m, and in some embodiments as low as 2 ?m. In part, this precise placement at small pitches is facilitated by the use of coarse and fine adjustment translators, and a guide connected to a compliant flange. The compliant flange and the guide facilitate consistency of location of a nanofiber yarn.

Abstract: A multilayer composite is disclosed comprising a heat shrinkable polymer layer and a nanofiber layer. Methods of forming the composite and uses thereof are also described.

Abstract: Actuators (artificial muscles) comprising twist-spun nanofiber twist-inserted polymer fibers generate tensile actuation when powered electrically, photonically, chemically, thermally, by absorption, or by other means. These artificial muscles utilize coiled polymer fibers and can be either neat or comprising a guest. In some embodiments, the coiled polymer fibers actuator can be incorporated into an article, such as a textile, braid, clothing, smart packaging, or a mechanical system, and the coiled polymer fiber in the coiled polymer fiber actuator can have a stroke amplification factor of 5 or greater.

Abstract: Actuators (artificial muscles) comprising twist-spun nanofiber yarn or twist-inserted polymer fibers generate torsional actuation when powered electrically, photonically, chemically, thermally, by absorption, or by other means. These artificial muscles utilize coiled yarns/polymer fibers and can be either neat or comprising a guest. In some embodiments, the actuator system includes a twisted and coiled polymer fiber actuator, and at least one of (i) wire connections that enable electrical heating of the twisted and coiled polymer fiber actuator, (ii) a radiation source and radiation pathway that enables photothermal heating of the twisted and coiled polymer fiber actuator, and (iii) a delivery system for delivering chemicals whose reaction produces heating of the twisted and coiled polymer fiber actuator.

Abstract: Systems for fabricating nanofiber yarn at rates of at least 30 m/min (1.8 kilometers (km)/hour (hr)) using a “false twist” nanofiber yarn spinner and a false twist spinning technique are disclosed. In a false twist spinning technique, a twist is introduced to nanofibers in a strand by twisting the nanofibers at points between ends of the strand. This is in contrast to the “true twist” technique where one end of a strand is fixed and the opposing end of the strand is rotated to introduce the twist to intervening portions of yarn.

Abstract: Techniques are described for controlling widths of nanofiber sheets drawn from a nanofiber forest. Nanofiber sheet width can be controlled by dividing or sectioning the nanofiber sheet in its as-drawn state into sub-sheets as the sheet is being drawn. A width of a sub-sheet can be controlled or selected so as to contain regions of uniform nanofiber density within a sub-sheet (thereby improving nanofiber yarn consistency) or to isolate an inhomogeneity (whether a discontinuity is the sheet (e.g., a tear) or a variation in density) within a sub-sheet. Techniques for dividing a nanofiber sheet into sub-sheets includes mechanical, corona, and electrical arc techniques.

Abstract: One or more nanofiber yarns can be placed in contact with one or more nanofiber sheets. The nanofiber yarns, which include single-ply and multi-ply nanofiber yarns, provide added mechanical stability to a nanofiber sheet that decreases the likelihood of a nanofiber sheet wrinkling, folding, or otherwise becoming stuck to itself. Furthermore, the nanofiber yarns integrated with the nanofiber sheet can also act as a mechanism to prevent the propagation of tears through the nanofiber sheet. In some cases, an infiltrating material can be infiltrated into interstitial spaces defined by the nanofibers within both the nanofiber yarns and the nanofiber sheets. The infiltrating material can then form a continuous network throughout the nanofiber yarns and the nanofiber sheet.

Abstract: Examples described include composite nanofibers sheets that have been “infiltrated” with a polymer (i.e., the polymer has flowed past a surface of the nanofiber sheet and into at least some of spaces within the sheet defined by the nanofibers). An adhesive nanofiber tape is formed when the infiltrating polymer is an adhesive and the adhesive infiltrates the nanofiber sheet from a one major surface of the nanofiber sheet. In other described examples, some portions of nanofibers in the sheet have been conformally coated with at least one metal layer.

Abstract: A dispenser is described for dispensing nanofiber yarns that includes a housing that defines an inlet, an outlet, and a chamber. A spool, around which is wound a length of nanofiber yarn, is disposed within the chamber defined by the housing. The nanofiber yarn is threaded from the chamber through the outlet and can be dispensed in a controlled way that reduces the likelihood of developing knots within the nanofiber yarn, and which facilitates convenient application of the yarn onto an underlying surface. In some cases, the dispenser can be used to concurrently dispense an adhesive or other polymer along with the nanofiber yarn.

Abstract: Techniques are described for controlling widths of nanofiber sheets drawn from a nanofiber forest. Nanofiber sheet width can be controlled by dividing or sectioning the nanofiber sheet in its as-drawn state into sub-sheets as the sheet is being drawn. A width of a sub-sheet can be controlled or selected so as to contain regions of uniform nanofiber density within a sub-sheet (thereby improving nanofiber yarn consistency) or to isolate an inhomogeneity (whether a discontinuity is the sheet (e.g., a tear) or a variation in density) within a sub-sheet. Techniques for dividing a nanofiber sheet into sub-sheets includes mechanical, corona, and electrical arc techniques.

Abstract: A carbo nanofiber nerve scaffold includes a cylindrical helix, a bundle of aligned carbon nanofiber yarns, and a carbon nanofiber sheet. The cylindrical helix includes a surgical suture material, and the cylindrical helix defines an interior of the carbon nanofiber nerve scaffold. The bundle of aligned carbon nanofiber yarns is disposed within the interior of the cylindrical helix. The carbon nanofiber sheet is disposed around the cylindrical helix on a side of the cylindrical helix opposite of the interior.

Abstract: Methods, systems, and apparatus for fabricating nanofiber yarn at rates of at least 30 m/min (1.8 kilometers (km)/hour (hr)) using a “false twist” nanofiber yarn spinner and a false twist spinning technique are disclosed. In a false twist spinning technique, a twist is introduced to nanofibers in a strand by twisting the nanofibers at points between ends of the strand. This is in contrast to the “true twist” technique where one end of a strand is fixed and the opposing end of the strand is rotated to introduce the twist to intervening portions of yarn.