Patents by Inventor Kripa K. Varanasi

Kripa K. Varanasi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20140332462
    Abstract: Hierarchical porous membranes suitable for use in oil/water separation processes are provided. The membranes described herein are particularly well suited for separating trace amounts of water (e.g., no greater than 3 wt % water content, no greater than 1 wt % water content, or 50-1000 ppm water) from oil in droplets less than 1 um in size. The membranes have a wide range of applications, including deep seep oil exploration, oil purification, and oil spill cleanup.
    Type: Application
    Filed: June 12, 2014
    Publication date: November 13, 2014
    Inventors: Brian Richmond Solomon, Kripa K. Varanasi, Md. Nasim Hyder
  • Publication number: 20140314947
    Abstract: The present disclosure provides, among other things, scale-coated surfaces, vessels with controlled deposits of scale, and associated methods for enhanced boiling heat transfer. It is presently found that creating and/or maintaining a scale deposit at a controlled thickness actually enhances a type of boiling called nucleate boiling, which improves heat transfer.
    Type: Application
    Filed: August 22, 2013
    Publication date: October 23, 2014
    Applicant: Massachusetts Institute of Technology
    Inventors: Kripa K. Varanasi, Christopher Jameson Love
  • Publication number: 20140314982
    Abstract: Presented herein are articles and methods featuring substrates with thin, uniform polymeric films grafted (e.g., covalently bonded) thereupon. The resulting coating provides significant reductions in thermal resistance, drop shedding size, and degradation rate during dropwise condensation of steam compared to existing coatings. Surfaces that promote dropwise shedding of low-surface tension condensates, such as liquid hydrocarbons, are also demonstrated herein.
    Type: Application
    Filed: February 14, 2014
    Publication date: October 23, 2014
    Applicant: Massachusetts Institute of Technology
    Inventors: Adam T. Paxson, Jose L. Yagüe, Kripa K. Varanasi, Karen K. Gleason, Andong Liu
  • Publication number: 20140291420
    Abstract: This invention relates generally to an article that includes a non-wetting surface having a dynamic contact angle of at least about 90°. The surface is patterned with macro-scale features configured to induce controlled asymmetry in a liquid film produced by impingement of a droplet onto the surface, thereby reducing time of contact between the droplet and the surface.
    Type: Application
    Filed: June 11, 2014
    Publication date: October 2, 2014
    Inventors: Rajeev Dhiman, James C. Bird, Hyukmin Kwon, Kripa K. Varanasi
  • Publication number: 20140290699
    Abstract: This invention relates generally to articles, devices, and methods for inhibiting or preventing the formation of scale during various industrial processes. In certain embodiments, a vessel is provided for use in an industrial process, the vessel having a textured, liquid-impregnated surface in contact with a mineral solution, wherein the liquid-impregnated surface comprises a matrix of features spaced sufficiently close to stably contain an impregnating liquid lubricant therebetween or therewithin, wherein the impregnating lubricant has a low surface energy density, and wherein the spreading coefficient Sos(w) of the impregnating lubricant (subscript ‘o’) on the substrate (subscript ‘s’) in the presence of the salt solution (subscript ‘w’) is greater than zero, such that the impregnating lubricant fully submerges the textured substrate.
    Type: Application
    Filed: February 28, 2014
    Publication date: October 2, 2014
    Inventors: Srinivas Prasad Bengaluru Subramanyam, Gisele Azimi, Jonathan David Smith, Kripa K. Varanasi
  • Publication number: 20140178611
    Abstract: In certain embodiments, the invention is directed to apparatus comprising a liquid-impregnated surface, said surface comprising an impregnating liquid and a matrix of solid features spaced sufficiently close to stably contain the impregnating liquid therebetween or therewithin, and methods thereof. In some embodiments, one or both of the following holds: (i) 0<??0.25, where ? is a representative fraction of the projected surface area of the liquid-impregnated surface corresponding to non-submerged solid at equilibrium; and (ii) Sow(a)<0, where Sow(a) is spreading coefficient, defined as ?wa??wo??oa, where ? is the interfacial tension between the two phases designated by subscripts w, a, and o, where w is water, a is air, and o is the impregnating liquid.
    Type: Application
    Filed: November 19, 2013
    Publication date: June 26, 2014
    Applicant: Massachusetts Institute of Technology
    Inventors: J. David Smith, Sushant Anand, Srinivas Prasad Bengaluru Subramanyam, Konrad Rykaczewski, Kripa K. Varanasi
  • Publication number: 20130340840
    Abstract: Methods described herein provide a way to reduce or eliminate drag and adhesion of a substance flowing over a surface by creating a vapor cushion via evaporation of a phase-changing material of or on the surface or encapsulated within textures of the surface. The vapor cushion causes the flowing substance to be suspended over the surface, greatly reducing friction, drag, and adhesion between the flowing substance and the surface. The temperature of the flowing substance is above the sublimation point and/or melting point of the phase-changing material. The phase-changing material undergoes a phase change (evaporation or sublimation) upon contact with the flowing substance due to local heat transfer from the flowing substance to the material, generating a vapor cushion between the solid or liquid material and the flowing substance.
    Type: Application
    Filed: June 13, 2013
    Publication date: December 26, 2013
    Inventors: Sushant Anand, Kripa K. Varanasi
  • Publication number: 20130335697
    Abstract: Described herein is a contact lens with high lubricity to eye tissue/fluid and inhibited nucleation on its surface. The contact lens has a surface textured to form a matrix of micro-scale and/or nano-scale solid (e.g., gel) features spaced sufficiently close to stably contain an impregnating liquid therebetween. The impregnating liquid fills spaces between the solid features, the surface stably contains the impregnating liquid between the solid features, and the impregnating liquid is substantially held in place between the plurality of solid features regardless of orientation of the surface and despite contact with the eye tissue during normal wear, insertion, and removal of the contact lens.
    Type: Application
    Filed: May 24, 2013
    Publication date: December 19, 2013
    Inventors: J. David Smith, Rajeev Dhiman, Adam T. Paxson, Christopher J. Love, Brian R. Solomon, Kripa K. Varanasi
  • Publication number: 20130333789
    Abstract: Described herein are conduits for conveying fluids and/or solids, the conduits having an interior surface that provide a high-slip boundary condition, thereby facilitating the flow of material therethrough. In some embodiments, the conduit has an interior surface with an impregnating liquid and a plurality of micro-scale and/or nano-scale solid features spaced sufficiently close to stably contain the impregnating liquid therebetween. The impregnating liquid fills spaces between the solid features, the interior surface stably contains the impregnating liquid between the solid features, and the impregnating liquid is substantially held in place between the plurality of solid features regardless of orientation of the interior surface and regardless of flow, passage, or removal of fluids and/or solids through, into, or out of the conduit.
    Type: Application
    Filed: May 24, 2013
    Publication date: December 19, 2013
    Applicant: Massachusetts Institute of Technology
    Inventors: J. David Smith, Rajeev Dhiman, Adam T. Paxson, Christopher J. Love, Brian R. Solomon, Kripa K. Varanasi
  • Publication number: 20130337027
    Abstract: Described herein are medical devices and medical implements with high lubricity to flesh (or biological fluid) and/or inhibited nucleation on its surface. The device has a surface comprising an impregnating liquid and a plurality of micro-scale and/or nano-scale solid features spaced sufficiently close to stably contain the impregnating liquid therebetween. The impregnating liquid fills spaces between said solid features, the surface stably contains the impregnating liquid between the solid features, and the impregnating liquid is substantially held in place between the plurality of solid features regardless of orientation of the surface.
    Type: Application
    Filed: May 24, 2013
    Publication date: December 19, 2013
    Applicant: Massachusetts Institute of Technology
    Inventors: J. David Smith, Rajeev Dhiman, Adam T. Paxson, Christopher J. Love, Brian R. Solomon, Kripa K. Varanasi
  • Patent number: 8574704
    Abstract: The invention is directed to an article with a liquid-impregnated surface, the surface having a matrix of features thereupon, spaced sufficiently close to stably contain a liquid therebetween or therewithin, and preferable also a thin film thereupon. The surface provides the article with advantageous non-wetting properties. Compared to previous non-wetting surfaces, which include a gas (e.g., air) entrained within surface textures, these liquid-impregnated surfaces are resistant to impalement and frost formation, and are therefore more robust.
    Type: Grant
    Filed: August 16, 2012
    Date of Patent: November 5, 2013
    Assignee: Massachusetts Institute of Technology
    Inventors: J. David Smith, Rajeev Dhiman, Kripa K. Varanasi, Ernesto Reza-Garduño Cabello
  • Publication number: 20130251942
    Abstract: This invention relates generally to an article that includes a base substrate and a hydrophobic coating on the base substrate, wherein the hydrophobic coating includes a rare earth element material (e.g., a rare earth oxide, a rare earth carbide, a rare earth nitride, a rare earth fluoride, and/or a rare earth boride). An exposed surface of the hydrophobic coating has a dynamic contact angle with water of at least about 90 degrees. A method of manufacturing the article includes providing the base substrate and forming a coating on the base substrate (e.g., through sintering or sputtering).
    Type: Application
    Filed: March 23, 2012
    Publication date: September 26, 2013
    Inventors: Gisele Azimi, Kripa K. Varanasi, Rajeev Dhiman, Adam T. Paxson, Kyukmin Kwon
  • Publication number: 20130251769
    Abstract: In certain embodiments, the invention relates to an article having a liquid-impregnated surface. The surface includes a matrix of solid features (e.g., non-toxic and/or edible features) spaced sufficiently close to stably contain a liquid therebetween or therewithin, wherein the liquid is non-toxic and/or edible. The article may contain, for example, a food or other consumer product, such as ketchup, mustard, or mayonnaise.
    Type: Application
    Filed: July 17, 2012
    Publication date: September 26, 2013
    Applicant: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    Inventors: Jonathan David Smith, Rajeev Dhiman, Adam T. Paxson, Christopher J. Love, Brian R. Solomon, Kripa K. Varanasi
  • Publication number: 20130251952
    Abstract: In certain embodiments, the invention relates to an article having a liquid-impregnated surface. The surface includes a matrix of solid features (e.g., non-toxic and/or edible features) spaced sufficiently close to stably contain a liquid therebetween or therewithin, wherein the liquid is non-toxic and/or edible. The article may contain, for example, a food or other consumer product, such as ketchup, mustard, or mayonnaise.
    Type: Application
    Filed: June 13, 2012
    Publication date: September 26, 2013
    Applicant: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    Inventors: Jonathan David Smith, Rajeev Dhiman, Adam T. Paxson, Christopher J. Love, Brian R. Solomon, Kripa K. Varanasi
  • Patent number: 8535779
    Abstract: In certain embodiments, the invention relates to an article having a liquid-impregnated surface. The surface includes a matrix of solid features (e.g., non-toxic and/or edible features) spaced sufficiently close to stably contain a liquid therebetween or therewithin, wherein the liquid is non-toxic and/or edible. The article may contain, for example, a food or other consumer product, such as ketchup, mustard, or mayonnaise.
    Type: Grant
    Filed: July 17, 2012
    Date of Patent: September 17, 2013
    Assignee: Massachusetts Institute of Technology
    Inventors: Jonathan David Smith, Rajeev Dhiman, Adam T. Paxson, Christopher J. Love, Brian R. Solomon, Kripa K. Varanasi
  • Publication number: 20130220813
    Abstract: The articles and methods described herein provide a way to manipulate condensation on a surface by micro/nano-engineering textures on the surface and filling the spaces between the texture features with an impregnating liquid that is stably held therebetween or therewithin. The articles and methods allow droplets of water, or other condensed phases, even in micrometer size range, to easily shed from the surface, thereby enhancing contact between a condensing species and the condensing surface. It has been found that dropwise condensation is enhanced by the use of an impregnating (secondary) liquid that has a relatively high surface tension, and, even more preferably, an impregnating liquid that has both a high surface tension and a low viscosity.
    Type: Application
    Filed: June 13, 2012
    Publication date: August 29, 2013
    Applicant: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    Inventors: Sushant Anand, Adam T. Paxson, Jonathan David Smith, Kripa K. Varanasi
  • Publication number: 20130032316
    Abstract: The invention is directed to an article with a liquid-impregnated surface, the surface having a matrix of features thereupon, spaced sufficiently close to stably contain a liquid therebetween or therewithin, and preferable also a thin film thereupon. The surface provides the article with advantageous non-wetting properties. Compared to previous non-wetting surfaces, which include a gas (e.g., air) entrained within surface textures, these liquid-impregnated surfaces are resistant to impalement and frost formation, and are therefore more robust.
    Type: Application
    Filed: November 22, 2011
    Publication date: February 7, 2013
    Inventors: Rajeev Dhiman, J. David Smith, Kripa K. Varanasi, Ernesto Reza-Garduño Cabello
  • Publication number: 20130032646
    Abstract: This invention relates generally to an article that includes a non-wetting surface having a dynamic contact angle of at least about 90°. The surface is patterned with macro-scale features configured to induce controlled asymmetry in a liquid film produced by impingement of a droplet onto the surface, thereby reducing time of contact between the droplet and the surface.
    Type: Application
    Filed: November 18, 2011
    Publication date: February 7, 2013
    Inventors: Rajeev Dhiman, James C. Bird, Hyukmin Kwon, Kripa K. Varanasi
  • Publication number: 20130034695
    Abstract: The invention is directed to an article with a liquid-impregnated surface, the surface having a matrix of features thereupon, spaced sufficiently close to stably contain a liquid therebetween or therewithin, and preferable also a thin film thereupon. The surface provides the article with advantageous non-wetting properties. Compared to previous non-wetting surfaces, which include a gas (e.g., air) entrained within surface textures, these liquid-impregnated surfaces are resistant to impalement and frost formation, and are therefore more robust.
    Type: Application
    Filed: August 16, 2012
    Publication date: February 7, 2013
    Applicant: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
    Inventors: J. David Smith, Rajeev Dhiman, Kripa K. Varanasi, Ernesto Reza-Garduño Cabello
  • Publication number: 20120201759
    Abstract: Hierarchical nanostructures and methods of fabrication. The structures include particles having a metal oxide outer shell with metal oxide wires extending from the outer shell. A multiscale structure according to the invention has particles above and below a critical size wherein the particles above the critical size have wires extending from the surface. These structures may be fabricated from a mixture prepared of relatively smaller metal particles having a size threshold below a threshold for nanowire formation and of relatively larger metal particles having a size above the threshold for nanowire formation. The mixture is oxidized at a selected temperature and for a selected time whereby the relatively smaller particles sinter and nanowires grow on the relatively larger particles thereby creating tunable hierarchical structures with metal-to-metal contact between the particles.
    Type: Application
    Filed: February 1, 2012
    Publication date: August 9, 2012
    Applicant: Massachusetts Institute of Technology
    Inventors: Christopher Jameson Love, J. David Smith, Kripa K. Varanasi