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).

  • Patent number: 9254496
    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: Grant
    Filed: November 18, 2011
    Date of Patent: February 9, 2016
    Assignee: Massachusetts Institute of Technology
    Inventors: Rajeev Dhiman, James C. Bird, Hyukmin Kwon, Kripa K. Varanasi
  • Publication number: 20150372350
    Abstract: In certain embodiments, the invention relates to an electrochemical device having a liquid lubricant impregnated surface. At least a portion of the interior surface of the electrochemical device includes a portion that includes a plurality of solid features disposed therein. The plurality of solid features define a plurality of regions therebetween. A lubricant is disposed in the plurality of regions which retain the liquid lubricant in the plurality of regions during operation of the device. An electroactive phase comes in contact with at least the portion of the interior surface. The liquid lubricant impregnated surface introduces a slip at the surface when the electroactive phase flows along the surface. The electroactive phase may be a yield stress fluid.
    Type: Application
    Filed: June 19, 2015
    Publication date: December 24, 2015
    Inventors: Brian Richmond Solomon, Xinwei Chen, Yet-Ming Chiang, Kripa K. Varanasi
  • Patent number: 9207025
    Abstract: Method for promoting nucleate boiling on an interior surface of a vessel for boiling fluid in an industrial process, the method comprising the steps of: providing the vessel having the interior surface; controllably depositing a scale layer having a non-zero thickness onto the interior surface; monitoring an average thickness, x, of the deposit of the layer; and maintaining the average thickness, x, of the layer below a predetermined value or within a predetermined range of values during the operational life of the vessel, wherein x<k/h, wherein k is the effective thermal conductivity of the interior surface of the vessel and h is the heat transfer coefficient at the interior surface of the vessel in contact with the boiling fluid.
    Type: Grant
    Filed: August 22, 2013
    Date of Patent: December 8, 2015
    Assignee: Massachusetts Institute of Technology
    Inventors: Kripa K. Varanasi, Christopher Jameson Love
  • Publication number: 20150144522
    Abstract: A container for housing a contact liquid includes a liquid-impregnated surface in contact with a contact liquid. The liquid-impregnated surface includes a first surface having a first roll off angle. A plurality of solid features are disposed on the first surface, such that a plurality of interstitial regions are defined between the plurality of solid features. An impregnating liquid is disposed in the interstitial regions and the interstitial regions are configured such that that the impregnating liquid is retained in the interstitial regions by capillary forces. The impregnating liquid disposed in the interstitial regions defines a second surface having a second roll off angle less than the first roll off angle. The container further includes a nucleation mechanism configured to nucleate and destabilize a film of the contact liquid disposed on the liquid-impregnated surface, such that the film of the contact liquid can be rapidly removed from the container.
    Type: Application
    Filed: November 25, 2014
    Publication date: May 28, 2015
    Inventors: Charles HIBBEN, J. David SMITH, Kripa K. VARANASI
  • Publication number: 20150125575
    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: December 23, 2014
    Publication date: May 7, 2015
    Inventors: Jonathan David Smith, Rajeev Dhiman, Adam T. Paxson, Christopher J. Love, Brian R. Solomon, Kripa K. Varanasi
  • Publication number: 20150111063
    Abstract: This invention relates generally to an article that includes a base substrate, an intermediate layer including at least one element or compound selected from titanium, chromium, indium, zirconium, tungsten, and titanium nitride on the 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 an intermediate layer coating on the base substrate (e.g., through sintering or sputtering) and then forming a hydrophobic coating on the intermediate layer (e.g., through sintering or sputtering).
    Type: Application
    Filed: October 30, 2014
    Publication date: April 23, 2015
    Inventors: Sami Khan, Gisele Azimi, Adam T. Paxson, Kripa K. Varanasi
  • Publication number: 20150075989
    Abstract: The invention provides methods and devices that use membranes to separate oil/water mixtures. The methods and devices have a wide range of applications, including deep seep oil exploration, oil purification, and oil spill cleanup. In some embodiments, at least one first membrane is provided, the first membrane being hydrophilic and oleophobic. The first membrane allows passage of water therethrough In some embodiments, a second membrane that is hydrophobic and oleophilic is provided in addition to the first membrane. The second membrane allows passage of oil therethrough.
    Type: Application
    Filed: March 14, 2014
    Publication date: March 19, 2015
    Applicant: Massachusetts Institute of Technology
    Inventors: Brian Richmond Solomon, Kripa K. Varanasi, Md Nasim Hyder
  • Patent number: 8983019
    Abstract: Textured surface for increasing Leidenfrost temperature. The texture comprises of surface features over multiple length scales—from micro to nanoscale—wherein the features at each length scale have a size, aspect ratio, and spacing selected to increase the Leidenfrost temperature. The structure includes an array of microscale structures disposed on the surface, the structure having size, aspect ratio and spacing selected to increase Leidenfrost temperature. The microscale structures may also include nanoscale structures on their surface to create a hierarchical structure. The structures result in an increased Leidenfrost temperature.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: March 17, 2015
    Assignee: Massachusetts Institute of Technology
    Inventors: Kripa K. Varanasi, Jonathan D. Smith, Adam T. Paxson, Christopher J. Love, Hyukmin Kwon, Dieter B. Brommer
  • Publication number: 20150066152
    Abstract: The present disclosure provides, among other things, prosthetic joint components having textured surface(s) for improving lubrication and increasing the useful life of the prosthetic joint components. The textured surface includes solid features configured to stably contain a biological fluid or a synthetic biological fluid therebetween or therewithin for a non-zero residence time.
    Type: Application
    Filed: September 3, 2013
    Publication date: March 5, 2015
    Applicant: Massachusetts Institute of Technology
    Inventors: Alexander H. Slocum, JR., Adam T. Paxson, Jonathan David Smith, Daniel H. Goodman, Kripa K. Varanasi
  • Patent number: 8940361
    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 mayonnaize.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: January 27, 2015
    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: 20150001153
    Abstract: The invention provides methods that use particles comprising a polymer to absorb and recover oil. The methods can be used for oil spill cleanup, oil recovery, extraction of oil from an oil-water emulsion, etc. In some embodiments, the particles are distributed to an oil spill site or another environment where oil needs to be separated. The particles may be retrieved after they have absorbed oil from the oil spill site. The oil may then be retrieved from the particles by compressing the particles or via other suitable oil removal methods.
    Type: Application
    Filed: March 14, 2014
    Publication date: January 1, 2015
    Applicant: Massachusetts Institute of Technology
    Inventors: Brian Richmond Solomon, Kripa K. Varanasi, Md Nasim Hyder
  • Publication number: 20140360880
    Abstract: Embodiments discussed herein relate to systems and methods for separating two or more phases of an emulsion or other mixture. The methods include providing the mixture with a net and unipolar charge (e.g., such that adjacent droplets therein acquire net and unipolar charges), thereby enhancing coalescence of like-phase droplets therein and producing, or enhancing the production of, two or more consolidated phases; and collecting the two or more consolidated phases.
    Type: Application
    Filed: April 16, 2014
    Publication date: December 11, 2014
    Applicant: Massachusetts Institute of Technology
    Inventors: Seyed Reza Mahmoudi, Kripa K. Varanasi
  • 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: 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: 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: 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: 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