Abstract: The present disclosure provides a stress micro mechanical system for measuring stress and strain in micro- and nano-fibers, tubes, and wires as well as for measuring the interface adhesion force and stress in nanofibers and nanotubes embedded in a polymer matrix. Also described are nanofibers comprising a cascade of surface ripples or periodic necks. Such surface features may be formed during cold drawing of electrospun nanofibers.

Abstract: A method for producing one or more nanofibers includes providing (a) a solution comprising a polymer and a solvent, (b) a nozzle for ejecting the solution, and (c) a stationary collector disposed a distance d apart from the nozzle. A voltage is applied between the nozzle and the stationary collector, and a jet of the solution is ejected from the nozzle toward the stationary collector. An electric field intensity of between about 0.5 and about 2.0 kV/cm is maintained, where the electric field intensity is defined as a ratio of the voltage to the distance d. At least a portion of the solvent from the stream is evaporated, and one or more polymer nanofibers are deposited on the stationary collector as the stream impinges thereupon. Each polymer nanofiber has an average diameter of about 500 nm or less and may serve as a precursor for carbon fiber production.

Abstract: The invention provides a stress micro mechanical system for measuring stress and strain in micro- and nano-fibers tubes, and wires as well as for measuring the interface adhesion force and stress in nanofibers and nanotubes embedded in a polymer matrix. A preferred system of the invention has a substrate for supporting a MEMS fabrication. The MEMS fabrication includes freestanding sample attachment points that are movable in a translation direction relative to one another when the substrate is moved and a sample is attached between the sample attachment points. An optical microscope images surfaces of the MEMS fabrication. Software conducts digital image correlation on obtained images to determine the movement of the surfaces at a resolution much greater than the hardware resolution of the optical microscope.

Abstract: A method for producing one or more nanofibers includes providing (a) a solution comprising a polymer and a solvent, (b) a nozzle for ejecting the solution, and (c) a stationary collector disposed a distance d apart from the nozzle. A voltage is applied between the nozzle and the stationary collector, and a jet of the solution is ejected from the nozzle toward the stationary collector. An electric field intensity of between about 0.5 and about 2.0 kV/cm is maintained, where the electric field intensity is defined as a ratio of the voltage to the distance d. At least a portion of the solvent from the stream is evaporated, and one or more polymer nanofibers are deposited on the stationary collector as the stream impinges thereupon. Each polymer nanofiber has an average diameter of about 500 nm or less and may serve as a precursor for carbon fiber production.

Abstract: The invention provides a stress micro mechanical system for measuring stress and strain in micro- and nano-fibers tubes, and wires as well as for measuring the interface adhesion force and stress in nanofibers and nanotubes embedded in a polymer matrix. A preferred system of the invention has a substrate for supporting a MEMS fabrication. The MEMS fabrication includes freestanding sample attachment points that are movable in a translation direction relative to one another when the substrate is moved and a sample is attached between the sample attachment points. An optical microscope images surfaces of the MEMS fabrication. Software conducts digital image correlation on obtained images to determine the movement of the surfaces at a resolution much greater than the hardware resolution of the optical microscope.