Patents by Inventor Sourabh Kumar

Sourabh Kumar 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: 9950462
    Abstract: Wrinkling of supported thin films is a strain-driven phenomenon that enables scalable and low-cost fabrication of periodic micro and nano scale structures. The morphology of wrinkles depends on both the magnitude and the nature of compressive strains that are applied to the thin film. This disclosure presents the methods to fabricate asymmetric 2-D wrinkled structures using biaxial compressive strains. The method relies on the dependence of wrinkle morphology on both strains and strain paths to generate asymmetric 2D wrinkles. Asymmetry is achieved by deliberately traversing the system through a strain state that creates cracks along a preferential direction. Fabricated patterns include non-uniform zigzag wrinkles that demonstrate period doubling only along one direction.
    Type: Grant
    Filed: December 17, 2016
    Date of Patent: April 24, 2018
    Inventors: Sourabh Kumar Saha, Martin Luther Culpepper
  • Publication number: 20180053133
    Abstract: A system and a method for optimizing supply of rental vehicles, comprising receiving customer data associated with a plurality of customers from a plurality of sources; classifying the customers into a plurality of segments, based on said data, each segment being indicative of vehicle rental preferences of customers in the segment; determining whether any customers have already opted for a vehicle rental; determining the destination and source location of the customer and predicting likely vehicle demand for different vehicles based on said classification and said determination.
    Type: Application
    Filed: August 14, 2017
    Publication date: February 22, 2018
    Inventors: Sourabh Kumar Maheshwari, Ankur Arora, Jaipal Singh Kumawat, Teja Chebrole, Shweta Khattar
  • Patent number: 9875333
    Abstract: The present disclosure relates to a system and method for electronic design automation. Embodiments may include receiving, using at least one processor, an electronic design and determining one or more graph based analysis (“GBA”) violating nodes associated with the electronic design. Embodiments may include identifying a non-covered violating node from the GBA violating nodes and determining a worst timing path through the non-covered violating node. Embodiments may further include invoking a path-based analysis (“PBA”) on the worst timing path and determining if the worst timing path satisfies the PBA analysis.
    Type: Grant
    Filed: January 19, 2016
    Date of Patent: January 23, 2018
    Assignee: Cadence Design Systems, Inc.
    Inventors: Sourabh Kumar Verma, Naresh Kumar, Ajay Tomar, Rakesh Agarwal, Umesh Gupta, Manish Bansal, Kaustav Guha, Prashant Sethia
  • Patent number: 9821507
    Abstract: The pattern complexity and functional value of wrinkled structures can be substantially increased by fabricating the wrinkles on pre-patterned quasi-planar substrates instead of flat substrates. This disclosure presents the methods for fabricating pre-patterned polymeric surfaces that can be subsequently used as the substrates during manufacture of complex wrinkled structures. Pre-patterned substrates are generated by imprinting the pre-patterns onto the substrates during the curing process. Suitability for post-curing use in fabrication of wrinkles is ensured by (i) delayed imprinting that occurs close to but before the gelation point and (ii) gradual alignment of pre-patterns to the direction of stretch that is applied later during manufacture of wrinkled structures.
    Type: Grant
    Filed: October 24, 2015
    Date of Patent: November 21, 2017
    Inventors: Sourabh Kumar Saha, Martin Luther Culpepper
  • Publication number: 20170217082
    Abstract: The range of stretch-tunability of sinusoidal wrinkled surfaces that are obtained by compression of supported thin films is limited by the emergence of a period-doubled mode at high compressive strains. This disclosure presents a method to suppress the emergence of the period-doubled mode at high strains. This is achieved by compressing pre-patterned supported thin films, wherein the pre-patterns are substantially similar to the natural pattern of the supported thin film system. As compared to flat thin film systems, pre-patterned thin film systems exhibit period doubling behavior at a higher compressive strain. The onset strain for emergence of period-doubling is tuned by altering the amplitude of the pre-patterns.
    Type: Application
    Filed: February 2, 2016
    Publication date: August 3, 2017
    Inventor: Sourabh Kumar Saha
  • Publication number: 20170095966
    Abstract: Wrinkling of supported thin films is a strain-driven phenomenon that enables scalable and low-cost fabrication of periodic micro and nano scale structures. The morphology of wrinkles depends on both the magnitude and the nature of compressive strains that are applied to the thin film. This disclosure presents the methods to fabricate asymmetric 2-D wrinkled structures using biaxial compressive strains. The method relies on the dependence of wrinkle morphology on both strains and strain paths to generate asymmetric 2D wrinkles. Asymmetry is achieved by deliberately traversing the system through a strain state that creates cracks along a preferential direction. Fabricated patterns include non-uniform zigzag wrinkles that demonstrate period doubling only along one direction.
    Type: Application
    Filed: December 17, 2016
    Publication date: April 6, 2017
    Inventor: Sourabh Kumar Saha
  • Patent number: 9597833
    Abstract: Wrinkling of thin films is a strain-driven process that enables scalable and low-cost fabrication of periodic micro and nano scale patterns. However, real-world application is limited by the inability of current tools to provide the means for applying large, accurate, and non-equal biaxial strains via a device that can fit within the vacuum chambers that are required for thin film deposition/growth during wrinkling. The present biaxial tensile stage is a compact system that enables one to apply large and accurate non-equal biaxial strains to elastomeric films. It consists of (i) fixtures to clamp and hold films onto the stage, (ii) linear bearings for motion guidance, (iii) integrated actuators for real-time stretch control, (iv) base with kinematic coupling for registration to a metrology system, and (v) the structural frame.
    Type: Grant
    Filed: January 6, 2015
    Date of Patent: March 21, 2017
    Inventors: Sourabh Kumar Saha, Martin Luther Culpepper
  • Publication number: 20160039142
    Abstract: The pattern complexity and functional value of wrinkled structures can be substantially increased by fabricating the wrinkles on pre-patterned quasi-planar substrates instead of flat substrates. This disclosure presents the methods for fabricating pre-patterned polymeric surfaces that can be subsequently used as the substrates during manufacture of complex wrinkled structures. Pre-patterned substrates are generated by imprinting the pre-patterns onto the substrates during the curing process. Suitability for post-curing use in fabrication of wrinkles is ensured by (i) delayed imprinting that occurs close to but before the gelation point and (ii) gradual alignment of pre-patterns to the direction of stretch that is applied later during manufacture of wrinkled structures.
    Type: Application
    Filed: October 24, 2015
    Publication date: February 11, 2016
    Inventors: Sourabh Kumar Saha, Martin Luther Culpepper
  • Publication number: 20150202821
    Abstract: Wrinkling of thin films is a strain-driven process that enables scalable and low-cost fabrication of periodic micro and nano scale patterns. However, real-world application is limited by the inability of current tools to provide the means for applying large, accurate, and non-equal biaxial strains via a device that can fit within the vacuum chambers that are required for thin film deposition/growth during wrinkling. The present biaxial tensile stage is a compact system that enables one to apply large and accurate non-equal biaxial strains to elastomeric films. It consists of (i) fixtures to clamp and hold films onto the stage, (ii) linear bearings for motion guidance, (iii) integrated actuators for real-time stretch control, (iv) base with kinematic coupling for registration to a metrology system, and (v) the structural frame.
    Type: Application
    Filed: January 6, 2015
    Publication date: July 23, 2015
    Inventors: Sourabh Kumar Saha, Martin Luther Culpepper
  • Publication number: 20150197058
    Abstract: This invention relates to the low-cost manufacture of a tunable physical topographic pattern and more particularly to the manufacture of micro and nano scale hierarchical periodic wrinkle patterns that are generated upon compression of supported thin films. Disclosed herein is (i) a composite material with tunable hierarchical wrinkle patterns, wherein the composite material comprises a stretched and pre-patterned base layer and a thin film that is conformally attached to the pre-patterned surface of the base layer, (ii) a method of fabricating the pre-patterned base via pattern replication, and (iii) a method of fabricating tunable hierarchical wrinkle patterns, wherein the pattern can be deterministically switched across the hierarchical and non-hierarchical states via strain control.
    Type: Application
    Filed: March 26, 2015
    Publication date: July 16, 2015
    Inventors: Sourabh Kumar Saha, Martin Luther Culpepper
  • Patent number: 8834146
    Abstract: Passive stamp alignment system. The system includes a stamp supported by a stamp holder resting on three balls affixed to a top platform. A bottom platform supports a substrate to be aligned with the stamp. Means are provided for moving either the top or the bottom platform and holding the other platform stationary so as to contact the substrate with the stamp whereby the stamp holder is lifted away from each of the balls in sequence resulting in alignment of the stamp and the substrate parallel to each other.
    Type: Grant
    Filed: October 24, 2012
    Date of Patent: September 16, 2014
    Assignee: Massachusetts Institute of Technology
    Inventors: Sourabh Kumar Saha, Martin L. Culpepper
  • Publication number: 20140113019
    Abstract: Passive stamp alignment system. The system includes a stamp supported by a stamp holder resting on three balls affixed to a top platform. A bottom platform supports a substrate to be aligned with the stamp. Means are provided for moving either the top or the bottom platform and holding the other platform stationary so as to contact the substrate with the stamp whereby the stamp holder is lifted away from each of the balls in sequence resulting in alignment of the stamp and the substrate parallel to each other.
    Type: Application
    Filed: October 24, 2012
    Publication date: April 24, 2014
    Applicant: Massachusetts Institute of Technology
    Inventors: Sourabh Kumar Saha, Martin L. Culpepper