Research Triangle Institute

Anthony L Andrady

David S Ensor

Li Han

Howard Jerome Walls

James Lynn Davis

Teri A Walker

Randall J Newsome

Purva Prabhu

A chemical sensor and a system and method for sensing a chemical species. The chemical sensor includes a plurality of nanofibers whose electrical impedance varies upon exposure to the chemical species, a substrate supporting and electrically isolating the fibers, and a set of electrodes connected to the plurality of fibers at spatially separated points to permit the electrical impedance of the plurality of fibers to be measured. The system includes the chemical sensor, an impedance measuring device coupled to the electrodes and configured to determine an electrical impedance of the plurality of fibers, and an analyzer configured to identify the chemical species based on a change in the electrical impedance. The method measures at least one change in an electrical impedance between spatially separated electrodes, and identifies the chemical species based on the measured change in the electrical impedance.

Polymer nanofiber-based electronic nose

A device for stimulable light emission that includes a fiber mat of nanofibers having an average fiber diameter in a range between 100 and 2000 nm, and includes plural stimulable particles disposed in association with the nanofibers. The stimulable particles produce secondary light emission upon receiving primary light at a wavelength &#x3bb;. The average fiber diameter is comparable in size to the wavelength &#x3bb; in order to provide scattering sites within the fiber mat for the primary light. Various methods for making suitable luminescent nanofiber mats include: electrospinning a polymer solution including or not including the stimulable particles and forming from the electrospun solution nanofibers having an average fiber diameter between 100 and 2000 nm. Methods, which electrospin without the stimulable particles, introduce the stimulable particles during electrospinning or after electrospinning to the fibers and therefore to the resultant fiber mat.

Luminescent device

A method for producing a fiber membrane of nanofibers that have both smooth and porous surface features. The method includes materials processing using polymer mixes with solvents and melt polymers with additives. The method includes nanomaterial incorporation onto a fiber structure after formation of the fiber structure. The fiber structure can be a part of a nanoparticle carrier material, a nanoparticle disposal medium, a lighting medium, and a catalysis medium.

Porous and non-porous nanostructures and application thereof

A filtration device including a filtration medium having a plurality of nanofibers of diameters less than 1 micron formed into a fiber mat in the presence of an abruptly varying electric field. The filtration device includes a support attached to the filtration medium and having openings for fluid flow therethrough. A device for making a filter material. The device includes an electrospinning element configured to electrospin a plurality of fibers from a tip of the electrospinning element, a collector opposed to the electrospinning element configured to collect electrospun fibers on a surface of the collector, and an electric field modulation device configured to abruptly vary an electric field at the collector at least once during electrospinning of the fibers. A method for making a filter material. The method provides a support having openings for fluid flow therethrough, electrospins nanofibers across an entirety of the openings, and abruptly varies an electric field at the collector at least once during electrospinning of the fibers.

Particle filter system incorporating nanofibers

Apparatus and method for producing fibrous materials in which the apparatus includes an extrusion element configured to electrospin a substance from which the fibers are to be composed by an electric field extraction of the substance from a tip of the extrusion element, a collector disposed from the extrusion element and configured to collect the fibers, a chamber enclosing the collector and the extrusion element, and a control mechanism configured to control a gaseous environment in which the fibers are to be electrospun. The apparatus and method provide a way to produce a fiber collection having a plurality of nanofibers disposed in relation to each other. The nanofibers in the fiber collection are preferentially oriented along a longitudinal axis of the fiber collection.

Electrospinning in a controlled gaseous environment

Apparatus and method for producing fibrous materials in which the apparatus includes an enclosure having an inlet configured to receive a substance from which the fibrous materials are to be composed, a common electrode disposed in the enclosure, and plural extrusion elements provided in a wall of the enclosure opposite the common electrode so as to define between the plural extrusion elements and the common electrode a space in communication with the inlet to receive the substance in the space. In the method, a substance from which the fibrous materials are to be composed is fed to the enclosure having the plural extrusion elements, a common electric field is applied to the extrusion elements in a direction in which the substance is to be extruded, the substance is extruded through the extrusion elements to tips of the extrusion elements, and the substance is electrosprayed from the tips to form the fibrous materials.

Electrospray/electrospinning apparatus and method

Apparatus and method for producing fibrous materials in which the apparatus includes an electrospinning element configured to electrospin a substance from which the fibers are to be composed by an electric field extraction of the substance from a tip of the electrospinning element, a collector disposed from the electrospinning element and configured to collect the fibers, a chamber enclosing the collector and the electrospinning element, and a control mechanism configured to control a gaseous environment in which the fibers are to be electrospun.

A chemical sensor and a system and method for sensing a chemical species. The chemical sensor includes a plurality of nanofibers whose electrical impedance varies upon exposure to the chemical species, a substrate supporting and electrically isolating the fibers, and a set of electrodes connected to the plurality of fibers at spatially separated points to permit the electrical impedance of the plurality of fibers to be measured. The system includes the chemical sensor, an impedance measuring device coupled to the electrodes and configured to determine an electrical impedance of the plurality of fibers, and an analyzer configured to identify the chemical species based on a change in the electrical impedance. The method measures at least one change in an electrical impedance between spatially separated electrodes connected to a plurality of fibers upon exposure of the fibers to the chemical species, and identifies the chemical species based on the measured change in the electrical impedance.

Luminescent device including nanofibers and light stimulable particles disposed on a surface of or at least partially within the nanofibers

An apparatus and method in which the apparatus includes a first electrospinning device configured to electrospin first fibers of a first substance, a second electrospinning device configured to electrospin second fibers of a second substance such that first and second fibers combine in a mat formation region, and a biasing device configured to bias the first electrospinning device with a first electric polarity and to bias the second electrospinning device with a second electric polarity of opposite polarity to the first electric polarity to promote attraction and coalescence between the first and second fibers. The method electrospins under the first electric polarity first fibers from the first substance, electrospins under the second electric polarity fibers from the second substance, and coalesces the first and second fibers to form the fiber mat.

Nanofiber mats and production methods thereof

Apparatus and method for producing fibrous materials in which the apparatus includes an extrusion element configured to electrospin a substance from which the fibers are to be composed by an electric field extraction of the substance from a tip of the extrusion element, a collector disposed from the extrusion element and configured to collect the fibers, a chamber enclosing the collector and the extrusion element, and a control mechanism configured to control a gaseous environment in which the fibers are to be electrospun. The method includes providing a substance from which the fibers are to be composed to a tip of an extrusion element, applying an electric field to the extrusion element in a direction of the tip, controlling a gaseous environment about where the fibers are to be electrospun, and electrospinning the substance from the tip of the extrusion element by an electric field extraction of the substance from the tip into the controlled gaseous environment.

Apparatus and method for electrospinning fibers in which the apparatus includes a spray head having a longitudinal axis and including at least one electrospinning element disposed in a peripheral wall of the spray head surrounding the longitudinal axis. The electrospinning element includes a passage by which a substance from which the fibers are to be electrospun is provided to a tip of the extrusion electrospinning element. The electrospinning element extends from the peripheral wall in a direction from the longitudinal axis and is configured to electrospin the fibers by electric field extraction of the substance from the tip of the extrusion electrospinning element. Accordingly, the method includes providing a substance from which the fibers are to be composed to a tip of an electrospinning element in a peripheral wall of a spray head having a longitudinal axis, rotating the spray head or a collector configured to receive the fibers around the longitudinal axis, applying in a direction from the longitudinal axis of the spray head an electric field to the tip of the electrospinning element to electrospin by electric field extraction the substance from the tip of the electrospinning element to form the fibers, and collecting the fibers on the collector.

Growing community of inventors

Apex, NC, United States of America

Anthony L Andrady