Patents by Inventor Yogesh B. Gianchandani
Yogesh B. Gianchandani 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).
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Publication number: 20070281304Abstract: Disclosed herein is a method of collecting suspensions in a liquid film including the steps of developing a variation in surface tension at a gas-liquid interface of the liquid film to generate a circulating flow pattern within the liquid film, and scanning the liquid film with the circulating flow pattern for entrapment of the suspensions in the flow pattern by re-directing the variation in the surface tension across the gas-liquid interface of the liquid film.Type: ApplicationFiled: June 5, 2006Publication date: December 6, 2007Applicant: THE REGENTS OF THE UNIVERSITY OF MICHIGANInventors: Yogesh B. Gianchandani, Amar S. Basu
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Patent number: 7262066Abstract: Systems and methods are described for identifying characteristics and defects in material such as semiconductors. Methods include scanning a thermal probe in the vicinity of a semiconductor sample, applying stimuli to the thermal probe, and monitoring the interaction of the thermal probe and the semiconductor. The stimulus can be applied by a variety of methods, including Joule heating of a resistor in the proximity of the probe tip, or optically heating a tip of the thermal probe using a laser. Applications of the invention include identification of voids in metallic layers in semiconductors; mapping dopant concentration in semiconductors; measuring thickness of a sample material; mapping thermal hot spots and other characteristics of a sample material.Type: GrantFiled: September 1, 2005Date of Patent: August 28, 2007Assignee: PicoCal, Inc.Inventors: Shamus McNamara, Yogesh B. Gianchandani
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Patent number: 7157718Abstract: Microfabricated, gas-filled radiation detector assemblies, methods of making and using same and interface circuit for use therewith are provided. The assembly includes a micromachined radiation detector including a set of spaced-apart electrodes and an ionization gas between the electrodes. A housing has a chamber for housing the detector including the gas. The housing of the assembly also includes a window which allows passage of charged particles therethrough to ionize the gas to create electrons which, in turn, create an electron cascade in the gas between the electrodes when the set of electrodes is biased.Type: GrantFiled: April 30, 2004Date of Patent: January 2, 2007Assignee: The Regents of the University of MichiganInventors: Yogesh B. Gianchandani, Chester G. Wilson
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Patent number: 7142303Abstract: A micro-discharge optical source apparatus and a method and system which utilizes the apparatus to analyze a sample are provided. The apparatus includes a substrate and an anode electrode and a cathode electrode supported on the substrate. One of the electrodes, such as the cathode, is preferably a liquid electrode. The electrodes are spaced apart to define an inter-electrode gap therebetween. The apparatus further includes a voltage source for applying a voltage between the electrodes sufficient to generate a glow micro-discharge in the gap to cause a first emission having a first desired excitation spectrum. An optical element is integrated with the substrate to direct the first emission to travel along an optical path including an axis. In one embodiment, the system detects the direct fluorescence of a sample such as tryptophan and other amino acids. In another embodiment, the system detects fluorescence of dye-labeled biochemicals.Type: GrantFiled: September 10, 2004Date of Patent: November 28, 2006Assignee: The Regents of the University of MichiganInventors: Yogesh B. Gianchandani, Ghester G. Wilson, Long Que, Bhaskar Mitra, Ponnambalam Selvaganapathy
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Patent number: 7116115Abstract: A micromachined probe apparatus and methods for making and using same to characterize liquid in a fluidic channel and map embedded charge in a sample on a substrate are provided. The probe apparatus includes an integrated scanning tip and a dither actuation mechanism. The actuation is achieved using a bent-beam electrothermal actuator, and the probe tip is insulated from the actuator with a wide isolation gap. The device is fabricated by a modified micro electro-discharge machining process which allows electrical isolation within the micromachined structure using an epoxy plug. The apparatus may be used to measure changes in the external surface potential of a microfluidic channel as a function of varying pH of liquid inside the channel. The apparatus also may be used to map embedded charge in a thin layer on a substrate, showing it to be suitable for monitoring microelectronics manufacturing processes.Type: GrantFiled: May 24, 2004Date of Patent: October 3, 2006Assignees: The Regents of the University of Michigan, Wisconsin Alumni Research FoundationInventors: Yogesh B. Gianchandani, Larry L. Chu, Kenichi Takahata, Ponnambalam Selvaganapathy, Juda L. Shohet
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Patent number: 7073938Abstract: A relatively simple and inexpensive micromachined arrayed thermal probe apparatus, system for thermal scanning a sample in a contact mode and cantilevered reference probe for use therein can be used for a variety of microscopy and microcalorimetry applications ranging from the monitoring of processes in semiconductor manufacturing to the characterization of nano-scale materials, imaging of biological cells, and even data storage. Probes are designed to have very high thermal isolation and high mechanical compliance, providing advantages in both performance and ease of operation. In particular, an array of probes can be used for high throughput contact mode scanning of soft samples without mechanical feedback, and can, therefore, be used in wide arrays for high-speed measurements over large sample surfaces. The probes are preferably manufactured by a photolithographic fabrication process, which permits large numbers of probes to be made in a uniform and reproducible manner at low cost.Type: GrantFiled: January 19, 2004Date of Patent: July 11, 2006Assignee: The Regents of the University of MichiganInventors: Yogesh B. Gianchandani, Shamus P. McNamara, Joohyung Lee, Amar Basu
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Patent number: 6951798Abstract: A method of bonding multiple layers is provided. The method includes the steps of stacking the multiple layers on top of each other and volumetrically heating the stack of multiple layers to a predetermined temperature. It is preferred that the stack is heated by electromagnetic induction.Type: GrantFiled: May 29, 2002Date of Patent: October 4, 2005Assignee: Wisconsin Alumni Research FoundationInventors: John H. Booske, Keith J. Thompson, Yogesh B. Gianchandani, Reid F. Cooper
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Patent number: 6827870Abstract: Plasma etching or deposition is performed over substrates using spatially localized micro-plasmas operating in parallel with each other. A plasma generating electrode is positioned closely adjacent to an exposed surface of the substrate, as on the surface of a dielectric layer applied to the substrate. A selected pressure of the gas in the region of the electrode and the substrate is established, and a voltage is applied between the plasma generating electrode and the substrate or a second electrode to ignite a plasma in the region between the plasma generating electrode and the substrate for a selected period of time. This plasma is limited to the region of the plasma generating electrode adjacent to the exposed surface so that the substrate is plasma treated in a desired pattern.Type: GrantFiled: October 11, 2000Date of Patent: December 7, 2004Assignee: Wisconsin Alumni Research FoundationInventors: Yogesh B. Gianchandani, Chester G. Wilson
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Publication number: 20040202226Abstract: A relatively simple and inexpensive micromachined arrayed thermal probe apparatus, system for thermal scanning a sample in a contact mode and cantilevered reference probe for use therein can be used for a variety of microscopy and microcalorimetry applications ranging from the monitoring of processes in semiconductor manufacturing to the characterization of nano-scale materials, imaging of biological cells, and even data storage. Probes are designed to have very high thermal isolation and high mechanical compliance, providing advantages in both performance and ease of operation. In particular, an array of probes can be used for high throughput contact mode scanning of soft samples without mechanical feedback, and can, therefore, be used in wide arrays for high-speed measurements over large sample surfaces. The probes are preferably manufactured by a photolithographic fabrication process, which permits large numbers of probes to be made in a uniform and reproducible manner at low cost.Type: ApplicationFiled: January 19, 2004Publication date: October 14, 2004Inventors: Yogesh B. Gianchandani, Shamus P. McNamara, Joohyung Lee, Amar Basu
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Publication number: 20040179946Abstract: A number of micromachined devices including a micromachined pump for on-chip vacuum is provided. For example, a single-chip micromachined implementation of a Knudsen pump having one or more stages and which uses the principle of thermal transpiration with no moving parts is provided. A six-mask microfabrication process to fabricate the pump using a glass substrate and silicon wafer is shown. The Knudsen pump and two integrated pressure sensors occupy an area of 1.5 mm×2 mm. Measurements show that while operating in standard laboratory conditions, this device can evacuate a cavity to 0.46 atm using 80 mW input power. High thermal isolation is obtained between a polysilicon heater of the pump and the rest of the device.Type: ApplicationFiled: January 5, 2004Publication date: September 16, 2004Inventors: Yogesh B. Gianchandani, Shamus P. McNamara
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Publication number: 20040149294Abstract: An assembly and planar structure for use therein which is expandable into a 3-D structure such as a stent and device for making the planar structure are provided. The planar structure permits the use of planar batch manufacturing technologies to fabricate coronary artery stents. Stents with different wall patterns are fabricated from 50 &mgr;m thick stainless steel foil using micro-electro-discharge machining, and expanded to tubular shapes by using angioplasty balloons. The stents are free-standing. The free-standing stents exhibit diameter variations of <±4%, almost zero radial recoil after deflation of the balloon, and longitudinal shrinkage of <3% upon expansion. A variation of the stents uses breakable links to provide additional customization of electrical and mechanical properties. Loading tests reveal that the radial strengths match commercially available stents, while longitudinal compliance, at 0.02 m/N for a 4 mm long section of the stent, is substantially higher.Type: ApplicationFiled: December 16, 2003Publication date: August 5, 2004Inventors: Yogesh B. Gianchandani, Kenichi Takahata
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Patent number: 6692145Abstract: A micromachined thermal probe has a substrate with a surface and an edge, and at least one flexible probe body formed on the substrate that includes a cantilever beam section that extends from a proximal end outwardly to a distal end. A pair of conductors in the probe body extend to a junction at the distal end at which is formed a probe tip. Current passed through the conductors to the junction heats the probe tip, with changes in the effective probe resistance occurring as the probe tip is scanned over a sample with different thermal conductivities at different positions. A second flexible probe body may be mounted to the substrate and constructed similarly to the first probe body to act as a reference probe to allow compensation of the first probe. The probe body may be formed of layers of flexible polymer joined together over pairs of conductors, which is bent back onto itself and secured together at a proximal end of the cantilever beam.Type: GrantFiled: October 31, 2001Date of Patent: February 17, 2004Assignee: Wisconsin Alumni Research FoundationInventors: Yogesh B. Gianchandani, Mo-Huang Li, Julius Wu
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Patent number: 6686998Abstract: Glow discharge apparatus having liquid electrodes includes a substrate with a top surface on which cathode and anode electrodes are formed. The cathode electrode may be formed with a cathode terminal port formed to hold a liquid which is spaced from the anode electrode by an inter-electrode surface of the substrate. Electrical conductors are connected to the anode and cathode electrodes to allow a voltage to be applied between them, resulting in a glow discharge in the gap over the inter-electrode surface that causes sputtering of the liquid in the cathode terminal port into the glow discharge. Excitation by the glow discharge of the sputtered or evaporated liquid allows spectroscopic analysis of the constituents of the liquid in the electrode.Type: GrantFiled: November 30, 2001Date of Patent: February 3, 2004Assignee: Wisconsin Alumni Research FoundationInventors: Yogesh B. Gianchandani, Chester G. Wilson
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Patent number: 6624377Abstract: A micro-electro-discharge machining apparatus includes a substrate, a plurality of electrically conductive electrodes on the substrate arranged in an array, and a plurality of electrical interconnect lines formed on the substrate extending to one or more of the electrodes. An electrical power source is connected from one of its terminals through a resistor to each of the interconnect lines and from its other terminal to a workpiece to be machined. The electrodes connected to different interconnect lines may charge and discharge independently of each other, speeding up the machining process. An interconnect line may extend individually to each electrode so that all of the electrodes can charge and discharge independently of the others. The capacitor that is charged to produce the discharge voltage may be a separate discrete capacitor or a conductive substrate.Type: GrantFiled: June 1, 2001Date of Patent: September 23, 2003Assignee: Wisconsin Alumni Research FoundationInventors: Yogesh B. Gianchandani, Kenichi Takahata
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Patent number: 6619123Abstract: A micromachined shock sensor has a substrate with a surface on which are formed an array of acceleration sensing units. Each sensing unit has a mount fixed to the substrate, a cantilever beam extending from the mount, and a proof mass fixed to the cantilever beam and supported above the substrate to permit translation of the proof mass and bending of the cantilever beam in a plane parallel to the substrate surface. Sensing electrodes are formed on the substrate on opposite sides of the proof mass such that displacement of the proof mass in response to acceleration brings the proof mass into contact with one or the other of the electrodes at a sufficient acceleration level, effectively closing a switch and providing an electrical output signal that can be detected. The multiple acceleration sensing units are formed to make contact at different levels of acceleration, allowing the shock sensor to allow measurements over a range of accelerations.Type: GrantFiled: June 4, 2001Date of Patent: September 16, 2003Assignee: Wisconsin Alumni Research FoundationInventors: Yogesh B. Gianchandani, Shamus P. McNamara
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Patent number: 6607305Abstract: A micromechanical actuator includes a plunger, having two magnet heads spaced from each other and joined to move together, that is supported for linear movement on a substrate. A magnetic core is supported on the substrate and has gaps in the core adjacent to the heads of the plunger. At least one permanent magnet is mounted to the plunger to move with it and forms, with the core, first and second magnetic circuits for flux which pass through the first and second heads of the plunger. A coil is coupled to the magnetic core to provide flux to the core. When the coil is supplied with DC current in one direction, the flux from the coil opposes the flux from the permanent magnet in one of the gaps and augments the flux in the other gap, causing the plunger to move in the direction of the gap having the augmented flux. After the plunger has switched positions, the electrical current in the coil is turned off, leaving the plunger latched in its switched position due to the flux from the permanent magnet.Type: GrantFiled: June 4, 2001Date of Patent: August 19, 2003Assignee: Wisconsin Alumni Research FoundationInventors: Kevin J. Fischer, Henry Guckel, Yogesh B. Gianchandani
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Patent number: 6606913Abstract: A micromachined strain sensor can be incorporated in a sealed package with other microelectrical and micromechanical components, with the residual strain being monitored electronically from outside the package to allow strain to be monitored during production and during the life of the component. The strain sensor includes at least one microstructural beam member anchored to a substrate at one position and having a portion which is freed from the substrate during formation to displace as a result of the strain in the beam member. At least one electrically conductive displaceable tine is connected to the beam member to be displaced as it is freed. A mating electrically conductive tine is mounted to the substrate adjacent to the displaceable tine such that a capacitor is formed between the adjacent tines. A plurality of displaceable tines and mating tines may be formed to increase the overall capacitance of the device.Type: GrantFiled: January 15, 1999Date of Patent: August 19, 2003Assignee: Wisconsin Alumni Research FoundationInventor: Yogesh B. Gianchandani
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Patent number: 6594994Abstract: Micromechanical actuation apparatus includes a substrate with an actuator mounted on the substrate and a micro-transmission mounted on the substrate coupled to the electrothermal actuator. The actuator, such as an electrothermal actuator, is responsive to electrical power to drive two output beams inwardly or outwardly in opposite directions. The micro-transmission couples the force from the two output beams and transmits the displacement of the output beams to an output node of the micro-transmission. The amplification of the micro-transmission provides a much larger displacement of a beam connected to the output node than the displacement of the output beams of the actuator.Type: GrantFiled: June 1, 2001Date of Patent: July 22, 2003Assignee: Wisconsin Alumni Research FoundationInventors: Yogesh B. Gianchandani, Joel A. Hetrick, Larry Li-Yang Chu
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Patent number: 6586699Abstract: Micro-electro-discharge machining is carried out utilizing a semiconductor array electrode having a substrate with a face surface and electrode protrusions extending from the face surface. The array electrode may be formed by lithographically patterning a semiconductor wafer such as a silicon wafer utilizing lithographic techniques of the type used in semiconductor device processing. The electrode protrusions in the surface of the substrate may be coated with a conducting metal. The electrode is positioned adjacent to a workpiece and a power supply is connected to the electrode and the workpiece to charge a capacitor until discharge takes place between the electrode protrusions and the surface of the workpiece, to electro-discharge-machine the workpiece to replicate the pattern of electrode protrusions into the workpiece.Type: GrantFiled: February 20, 2002Date of Patent: July 1, 2003Assignee: Wisconsin Alumni Research FoundationInventors: Yogesh B. Gianchandani, Kenichi Takahata
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Publication number: 20030103205Abstract: Glow discharge apparatus having liquid electrodes includes a substrate with a top surface on which cathode and anode electrodes are formed. The cathode electrode may be formed with a cathode terminal port formed to hold a liquid which is spaced from the anode electrode by an inter-electrode surface of the substrate. Electrical conductors are connected to the anode and cathode electrodes to allow a voltage to be applied between them, resulting in a glow discharge in the gap over the inter-electrode surface that causes sputtering of the liquid in the cathode terminal port into the glow discharge. Excitation by the glow discharge of the sputtered or evaporated liquid allows spectroscopic analysis of the constituents of the liquid in the electrode.Type: ApplicationFiled: November 30, 2001Publication date: June 5, 2003Inventors: Yogesh B. Gianchandani, Chester G. Wilson