Patents by Inventor Robert J. Littrell

Robert J. Littrell 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: 20210382972
    Abstract: Techniques for biometric authentication using a voice accelerometer and an acoustic transducer includes receiving a first signal representing an output by a voice accelerometer of a device and a second signal representing an output by an acoustic transducer of the device. Characteristics of each of the first signal and the second signal are compared with stored biometric characteristics for a user of the device. The user of the device is then authenticated based on the comparison.
    Type: Application
    Filed: June 4, 2021
    Publication date: December 9, 2021
    Inventors: Robert J. Littrell, Mathew Crowley
  • Publication number: 20210273152
    Abstract: A microphone including a casing having a front wall, a back wall, and a side wall joining the front wall to the back wall, a transducer mounted to the front wall, the transducer including a substrate and a transducing element, the transducing element having a transducer acoustic compliance dependent on the transducing element dimensions, a back cavity cooperatively defined between the back wall, the side wall, and the transducer, the back cavity having a back cavity acoustic compliance. The transducing element is dimensioned such that the transducing element length matches a predetermined resonant frequency and the transducing element width, thickness, and elasticity produces a transducer acoustic compliance within a given range of the back cavity acoustic compliance.
    Type: Application
    Filed: February 19, 2021
    Publication date: September 2, 2021
    Inventors: Karl Grosh, Robert J. Littrell
  • Patent number: 11088315
    Abstract: A piezoelectric MEMS microphone comprising a multi-layer sensor that includes at least one piezoelectric layer between two electrode layers, with the sensor being dimensioned such that it provides a near maximized ratio of output energy to sensor area, as determined by an optimization parameter that accounts for input pressure, bandwidth, and characteristics of the piezoelectric and electrode materials. The sensor can be formed from single or stacked cantilevered beams separated from each other by a small gap, or can be a stress-relieved diaphragm that is formed by deposition onto a silicon substrate, with the diaphragm then being stress relieved by substantial detachment of the diaphragm from the substrate, and then followed by reattachment of the now stress relieved diaphragm.
    Type: Grant
    Filed: December 22, 2017
    Date of Patent: August 10, 2021
    Assignee: THE REGENTS OF THE UNIVERSITY OF MICHIGAN
    Inventors: Karl Grosh, Robert J. Littrell
  • Patent number: 10964880
    Abstract: A microphone including a casing having a front wall, a back wall, and a side wall joining the front wall to the back wall, a transducer mounted to the front wall, the transducer including a substrate and a transducing element, the transducing element having a transducer acoustic compliance dependent on the transducing element dimensions, a back cavity cooperatively defined between the back wall, the side wall, and the transducer, the back cavity having a back cavity acoustic compliance. The transducing element is dimensioned such that the transducing element length matches a predetermined resonant frequency and the transducing element width, thickness, and elasticity produces a transducer acoustic compliance within a given range of the back cavity acoustic compliance.
    Type: Grant
    Filed: November 20, 2018
    Date of Patent: March 30, 2021
    Assignees: THE REGENTS OF THE UNIVERSITY OF MICHIGAN, VESPER TECHNOLOGIES INC.
    Inventors: Karl Grosh, Robert J. Littrell
  • Publication number: 20200408799
    Abstract: A sensor device that senses proper acceleration. The sensor device includes a substrate, a spacer layer supported over a first surface of the substrate, at least a first tapered cantilever beam element having a base and a tip, the base attached to the spacer layer, and which is supported over and spaced from the substrate by the spacer layer. The at least first tapered cantilever beam element tapers in width from the base portion to the tip portion. The at least first cantilever beam element further including at least a first layer comprised of a piezoelectric material, a pair of electrically conductive layers disposed on opposing surfaces of the first layer, and a mass supported at the tip portion of the at least first tapered cantilever beam element.
    Type: Application
    Filed: June 12, 2020
    Publication date: December 31, 2020
    Inventor: Robert J. Littrell
  • Patent number: 10825982
    Abstract: A piezoelectric Micro-Electro-Mechanical Systems (MEMS) device comprising: a physical element; and a piezoelectric sensor element, with the physical element positioned in proximity to a moving portion of the piezoelectric sensor element, and with proximity of the physical element to the moving portion reducing a probability of breakage of the piezoelectric sensor element by limiting an excursion of the piezoelectric sensor element, relative to a probability of breakage of the piezoelectric sensor element in another piezoelectric MEMS device without the physical element.
    Type: Grant
    Filed: September 11, 2015
    Date of Patent: November 3, 2020
    Assignee: Vesper Technologies Inc.
    Inventors: Robert J. Littrell, Karl Grosh, Craig Core, Yu Hui, Wang Kyung Sung
  • Publication number: 20200344555
    Abstract: A device comprising: a sensor; and a first circuit configured to detect when an input stimulus to the sensor satisfies one or more detection criteria, and further configured to produce a signal upon detection that causes adjustment of performance of the device; and a second circuit for processing input following detection, wherein the second circuit is configured to increase its power level following detection, relative to a power level of the second circuit prior to detection.
    Type: Application
    Filed: May 13, 2020
    Publication date: October 29, 2020
    Inventors: Robert J. Littrell, Ronald Gagnon, Karl Grosh
  • Publication number: 20200296513
    Abstract: A device that includes an adaptive acoustic detection circuit and an acoustic sensor device such as a microphone is described. The device includes in addition to the sensor a circuit configured to detect when an input stimulus to the sensor satisfies an adaptive threshold, and further configured to produce a signal upon detection that causes adjustment of performance of the device, wherein the adaptive threshold is a threshold value that varies over time in accordance with detected changes to sound of an environment in which the device is located.
    Type: Application
    Filed: March 16, 2020
    Publication date: September 17, 2020
    Inventors: Robert J. Littrell, Michael Carfore, Shuwan Xue
  • Publication number: 20200296530
    Abstract: An acoustic device is described and includes an acoustic sensor element configured to sense acoustic energy and produce an output signal and a threshold detector circuit including a switch having an input coupled to the output of the acoustic sensor element to receive the output signal, a control port that receives a control signal, and first and second output ports, a first channel including an analog-to-digital converter that operates at a first power level a second analog-to-digital converter that operates at a second higher power level, relative to the first power level and a threshold level detector that receives an output from the first analog-to-digital converter to produce the control signal having a first state that causes the switch feed the output signal from the acoustic sensor element to the second analog-to-digital converter when the first digitized output signal meets a threshold criteria.
    Type: Application
    Filed: March 16, 2020
    Publication date: September 17, 2020
    Inventor: Robert J. Littrell
  • Patent number: 10771889
    Abstract: A package comprises: a transducer; a substrate comprising an acoustic port, with the transducer attached to a surface of the substrate and over or adjacent to the acoustic port; and a venting mechanism for venting air or sound pressure from a device comprising the package, with the venting mechanism being affixed to the substrate and partially surrounding the acoustic port, and with the venting mechanism being dimensioned to filter out audio frequencies.
    Type: Grant
    Filed: November 21, 2016
    Date of Patent: September 8, 2020
    Assignee: Vesper Technologies Inc.
    Inventor: Robert J. Littrell
  • Patent number: 10715922
    Abstract: A device comprising: a sensor; and a first circuit configured to detect when an input stimulus to the sensor satisfies one or more detection criteria, and further configured to produce a signal upon detection that causes adjustment of performance of the device; and a second circuit for processing input following detection, wherein the second circuit is configured to increase its power level following detection, relative to a power level of the second circuit prior to detection.
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: July 14, 2020
    Assignee: Vesper Technologies Inc.
    Inventors: Robert J. Littrell, Ronald Gagnon, Karl Grosh
  • Publication number: 20200148532
    Abstract: A microphone including a casing having a front wall, a back wall, and a side wall joining the front wall to the back wall, a transducer mounted to the front wall, the transducer including a substrate and a transducing element, the transducing element having a transducer acoustic compliance dependent on the transducing element dimensions, a back cavity cooperatively defined between the back wall, the side wall, and the transducer, the back cavity having a back cavity acoustic compliance. The transducing element is dimensioned such that the transducing element length matches a predetermined resonant frequency and the transducing element width, thickness, and elasticity produces a transducer acoustic compliance within a given range of the back cavity acoustic compliance.
    Type: Application
    Filed: November 20, 2018
    Publication date: May 14, 2020
    Inventors: Karl Grosh, Robert J. Littrell
  • Patent number: 10566517
    Abstract: A transducer comprising: at least one piezoelectric layer; a first patterned conductive layer that is patterned with a first opening; a second patterned conductive layer that is patterned with a second opening; wherein at least one piezoelectric layer is between the first and the second patterned conductive layers in a stack; and wherein a position of the first opening is staggered relative to a position of the second opening in the stack to mitigate an occurrence of crack propagation through the layers.
    Type: Grant
    Filed: September 11, 2015
    Date of Patent: February 18, 2020
    Assignee: Vesper Technologies Inc.
    Inventors: Robert J. Littrell, Karl Grosh
  • Publication number: 20190281393
    Abstract: A transducer of the preferred embodiment including a transducer and a plurality of adjacent, tapered cantilevered beams. Each of the beams define a beam base, a beam tip, and a beam body disposed between the beam base and the beam tip. The beams are arranged such that each of the beam tips extends toward a common area. Each beam is joined to the substrate along the beam base and is free from the substrate along the beam body. A preferred method of manufacturing a transducer can include: depositing alternating layers of piezoelectric and electrode onto the substrate in block, processing the deposited layers to define cantilever geometry in block, depositing metal traces in block, and releasing the cantilevered beams from the substrate in block.
    Type: Application
    Filed: March 14, 2019
    Publication date: September 12, 2019
    Inventors: Karl Grosh, Robert J. Littrell
  • Patent number: 10284960
    Abstract: A transducer of the preferred embodiment including a transducer and a plurality of adjacent, tapered cantilevered beams. Each of the beams define a beam base, a beam tip, and a beam body disposed between the beam base and the beam tip. The beams are arranged such that each of the beam tips extends toward a common area. Each beam is joined to the substrate along the beam base and is free from the substrate along the beam body. A preferred method of manufacturing a transducer can include: depositing alternating layers of piezoelectric and electrode onto the substrate in block, processing the deposited layers to define cantilever geometry in block, depositing metal traces in block, and releasing the cantilevered beams from the substrate in block.
    Type: Grant
    Filed: May 1, 2015
    Date of Patent: May 7, 2019
    Assignee: Vesper Technologies Inc.
    Inventors: Karl Grosh, Robert J. Littrell
  • Publication number: 20190110132
    Abstract: A transducer and method for processing a MEMS transducer. In one aspect, the MEMS transducer includes a first plate and a second plate. The MEMS transducer can also include a spring substantially between the first plate and the second plate, the spring including first and second spring arms dimensioned to decrease vertical deflection mismatch between the first and second plates, relative to vertical deflection mismatch of the first and second plates independent of the spring.
    Type: Application
    Filed: September 19, 2016
    Publication date: April 11, 2019
    Inventor: Robert J Littrell
  • Publication number: 20190098417
    Abstract: A device comprising: a sensor; and a first circuit configured to detect when an input stimulus to the sensor satisfies one or more detection criteria, and further configured to produce a signal upon detection that causes adjustment of performance of the device; and a second circuit for processing input following detection, wherein the second circuit is configured to increase its power level following detection, relative to a power level of the second circuit prior to detection.
    Type: Application
    Filed: February 28, 2017
    Publication date: March 28, 2019
    Inventors: Robert J. Littrell, Ronald Gagnon, Karl Grosh
  • Patent number: 10170685
    Abstract: A microphone including a casing having a front wall, a back wall, and a side wall joining the front wall to the back wall, a transducer mounted to the front wall, the transducer including a substrate and a transducing element, the transducing element having a transducer acoustic compliance dependent on the transducing element dimensions, a back cavity cooperatively defined between the back wall, the side wall, and the transducer, the back cavity having a back cavity acoustic compliance. The transducing element is dimensioned such that the transducing element length matches a predetermined resonant frequency and the transducing element width, thickness, and elasticity produces a transducer acoustic compliance within a given range of the back cavity acoustic compliance.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: January 1, 2019
    Assignees: The Regents of The University of Michigan, Vesper Technologies Inc.
    Inventors: Karl Grosh, Robert J. Littrell
  • Patent number: 10001391
    Abstract: An electronic device comprises a sensor comprising first and second electrodes, with the sensor being configured for a first acoustic displacement due to input acoustic pressure; circuitry configured to measure a charge between the first and second electrodes due to the input acoustic pressure and to apply a voltage to cause a second acoustic displacement of the sensor that is out of phase with the first acoustic displacement, with the applied voltage further causing a charge to develop across the sensor, and with the first and second acoustic displacements causing an increase in damping in a resonance frequency of the sensor, relative to damping of the resonance frequency of the sensor prior to applying the voltage; and a passive electronic component configured to cancel out the charge developed across the sensor due to the applied voltage.
    Type: Grant
    Filed: August 13, 2015
    Date of Patent: June 19, 2018
    Assignee: Vesper Technologies Inc.
    Inventors: Robert J. Littrell, Karl Grosh
  • Publication number: 20180138391
    Abstract: A piezoelectric MEMS microphone comprising a multi-layer sensor that includes at least one piezoelectric layer between two electrode layers, with the sensor being dimensioned such that it provides a near maximized ratio of output energy to sensor area, as determined by an optimization parameter that accounts for input pressure, bandwidth, and characteristics of the piezoelectric and electrode materials. The sensor can be formed from single or stacked cantilevered beams separated from each other by a small gap, or can be a stress-relieved diaphragm that is formed by deposition onto a silicon substrate, with the diaphragm then being stress relieved by substantial detachment of the diaphragm from the substrate, and then followed by reattachment of the now stress relieved diaphragm.
    Type: Application
    Filed: December 22, 2017
    Publication date: May 17, 2018
    Inventors: Karl Grosh, Robert J. Littrell