# US 10,871,529 B2 · Spintronic mechanical shock and vibration sensor device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,871,529 B2 - Document ID: US10871529B2 - Status: Granted - Kind: B2 - Application number: 16/195,588 - Filed: 2018-11-19 - Published: 2020-03-12 - Granted: 2020-12-22 - Earliest claimed: 2018-09-11 - Assignees: Honeywell International Inc. - Applicants: Honeywell International Inc. - Inventors: Romney R. Katti; Edward F. Ambrose - Web page: https://patentgrep.com/patent/US10871529B2 ## CPC - G01H 11/06: by electric means - G01R 33/098: {comprising tunnel junctions, e.g. tunnel magnetoresistance sensors} - G01H 11/02: by magnetic means, e.g. reluctance - G01L 1/10: by measuring variations of frequency of stressed vibrating elements, e.g. of stressed strings (using resistance strain gauges G01L1/22) - G11C 11/1673: {Reading or sensing circuits or methods} - H01F 10/3254: {the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]} - H10N 50/10: Magnetoresistive devices - G01H: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) - G11C: STATIC STORES (semiconductor memory devices H10B) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract A magnetic tunnel junction (MTJ) based sensor device includes a MTJ element and processing circuitry. The MTJ element includes a free layer, a pinned layer, an elastic layer, and a tunnel barrier. The free layer is spaced apart from the pinned layer by the tunnel barrier and the elastic layer. The processing circuitry is configured to measure a resistance at the MTJ element and determine whether mechanical shock and vibration has occurred based on the resistance at the MTJ element. ## Claims ### Claim 1 A magnetic tunnel junction (MTJ) based sensor device, the device comprising: a MTJ element comprising a free layer, a pinned layer, an elastic layer, and a tunnel barrier, the free layer being spaced apart from the pinned layer by the tunnel barrier and the elastic layer, wherein the elastic layer changes in thickness in response to one or more of tensional stress or compressional stress; and processing circuitry electrically connected to the MTJ element and configured to: measure a resistance at the MTJ element; and determine whether mechanical shock and vibration has occurred based on the resistance at the MTJ element. ### Claim 2 (depends on 1) The device of claim 1, wherein the free layer is spaced apart from the tunnel barrier by the elastic layer. ### Claim 3 (depends on 1) The device of claim 1, wherein the tunnel barrier is spaced apart from the pinned layer by the elastic layer. ### Claim 4 (depends on 1) The device of claim 1, wherein the elastic layer is a first elastic layer, wherein the free layer is spaced apart from the tunnel barrier by the first elastic layer and wherein the tunnel barrier is spaced apart from the pinned layer by a second elastic layer. ### Claim 5 (depends on 1) The device of claim 1, wherein the tunnel barrier is a first tunnel barrier, wherein the free layer is spaced apart from the elastic layer by the first tunnel barrier, and wherein the elastic layer is spaced apart from the pinned layer by a second tunnel barrier. ### Claim 6 (depends on 1) The device of claim 1, wherein the tunnel barrier is a first tunnel barrier, wherein the elastic layer is a first elastic layer, wherein the free layer is spaced apart from the first elastic layer by the first tunnel barrier, wherein the first elastic layer is spaced apart from a second elastic layer by a second tunnel barrier, and wherein the second tunnel barrier is spaced apart from the pinned layer by the second elastic layer. ### Claim 7 (depends on 1) The device of claim 1, wherein the tunnel barrier is a first tunnel barrier, wherein the elastic layer is a first elastic layer, wherein the free layer is spaced apart from the first tunnel barrier by the first elastic layer, wherein the first tunnel barrier is spaced apart from a second tunnel barrier by a second elastic layer, and wherein the second elastic layer is spaced apart from the pinned layer by the second tunnel barrier. ### Claim 8 (depends on 1) The device of claim 1, wherein the tunnel barrier is a first tunnel barrier, wherein the elastic layer is a first elastic layer, wherein the free layer is spaced apart from the first tunnel barrier by the first elastic layer, wherein the first tunnel barrier is spaced apart from a second tunnel barrier by a second elastic layer, and wherein the second tunnel barrier is spaced apart from the pinned layer by a third elastic layer. ### Claim 9 (depends on 1) The device of claim 1, wherein the tunnel barrier is a first tunnel barrier, wherein the first tunnel barrier is spaced apart from a second tunnel barrier by the elastic layer, wherein the elastic layer is arranged below a lower surface of the first tunnel barrier and spaced apart from a first edge of the lower surface of the first tunnel barrier, and wherein the elastic layer is arranged above an upper surface of the second tunnel barrier and spaced apart from a first edge of the upper surface of the second tunnel barrier. ### Claim 10 (depends on 9) The device of claim 9, wherein the elastic layer is spaced apart from a second edge of the lower surface of the first tunnel barrier and wherein the elastic layer is spaced apart from a second edge of the upper surface of the second tunnel barrier. ### Claim 11 (depends on 1) The device of claim 1, wherein the free layer is spaced apart from the tunnel barrier by the elastic layer, wherein the elastic layer is arranged below a lower surface of the free layer and spaced apart from a first edge of the lower surface of the free layer, and wherein the elastic layer is arranged above an upper surface of the tunnel barrier and spaced apart from a first edge of the upper surface of the tunnel barrier. ### Claim 12 (depends on 11) The device of claim 11, wherein the elastic layer spaced apart from a second edge of the lower surface of the free layer and wherein the elastic layer is spaced apart from a second edge of the upper surface of the tunnel barrier. ### Claim 13 (depends on 1) The device of claim 1, wherein the tunnel barrier is spaced apart from the pinned layer by the elastic layer, wherein the elastic layer is arranged below a lower surface of the tunnel barrier and spaced apart from a first edge of the lower surface of the tunnel barrier, and wherein the elastic layer is arranged above an upper surface of the pinned layer and spaced apart from a first edge of the upper surface of the pinned layer. ### Claim 14 (depends on 13) The device of claim 13, wherein the elastic layer spaced apart from a second edge of the lower surface of the tunnel barrier and wherein the elastic layer is spaced apart from a second edge of the upper surface of the pinned layer. ### Claim 15 (depends on 1) The device of claim 1, wherein, to measure the resistance at the MTJ element, the processing circuitry is configured to measure a resistance between the pinned layer and the free layer; and wherein, to determine whether mechanical shock and vibration has occurred, the processing circuitry is configured to: determine mechanical shock and vibration has occurred when the measured resistance between the pinned layer and the free layer does not satisfy a mechanical shock and vibration threshold; and determine mechanical shock and vibration has not occurred when the measured resistance between the pinned layer and the free layer satisfies the mechanical shock and vibration threshold. ### Claim 16 (depends on 1) The device of claim 1, wherein the elastic layer comprises one or more sheets of Carbon, Graphene, an Elastomer. ### Claim 17 A method for detecting mechanical shock and vibration using a magnetic tunnel junction (MTJ) based sensor device, the method comprising: measuring, by processing circuitry, a resistance at a MTJ element, wherein the MTJ element comprises a free layer, a pinned layer, an elastic layer, and a tunnel barrier, the free layer being spaced apart from the pinned layer by the tunnel barrier and the elastic layer, wherein the elastic layer changes in thickness in response to one or more of tensional stress or compressional stress; and determining, by the processing circuitry, whether mechanical shock and vibration has occurred based on the resistance at the MTJ element. ### Claim 18 (depends on 17) The method of claim 17, wherein measuring the resistance at the MTJ element comprises measuring a resistance between the pinned layer and the free layer; and wherein determining whether mechanical shock and vibration has occurred comprises: determining mechanical shock and vibration has occurred when the measured resistance between the pinned layer and the free layer does not satisfy a mechanical shock and vibration threshold; and determining vibration threshold and determine mechanical shock and vibration has not occurred when the measured resistance between the pinned layer and the free layer satisfies the mechanical shock and vibration threshold. ### Claim 19 A magnetic tunnel junction (MTJ) based sensor device, the device comprising: means for measuring a resistance at a MTJ element, wherein the MTJ element comprises a free layer, a pinned layer, an elastic layer, and a tunnel barrier, the free layer being spaced apart from the pinned layer by the tunnel barrier and the elastic layer, wherein the elastic layer changes in thickness in response to one or more of tensional stress or compressional stress; and means for determining whether mechanical shock and vibration has occurred based on the resistance at the MTJ element. ### Claim 20 (depends on 1) The device of claim 1, wherein the resistance at the MTJ element is dependent on the thickness of the elastic layer.