# US 2021/0333085 A1 · Strain gauge having unbalanced bias for single sided applications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0333085 A1 - Document ID: US20210333085A1 - Status: Published application - Kind: A1 - Application number: 16/858,110 - Filed: 2020-04-24 - Published: 2021-10-28 - Earliest claimed: 2020-04-24 - Assignees: STMicroelectronics Asia Pacific Ptd Ltd - Applicants: STMicroelectronics Asia Pacific Pte Ltd - Inventors: Sa Hyang HONG; Jun Hwan KANG; Yun Sang ON - Web page: https://patentgrep.com/patent/US20210333085A1 ## CPC - G01B 7/18: {using change in resistance} - G06F 3/041: Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means - G01L 1/044: {of leaf springs} - G01L 1/225: {Measuring circuits therefor} - G01L 1/2287: {constructional details of the strain gauges (adjustable resistors H01C10/00)} - G06F 3/04144: {using an array of force sensing means (position sensing using the local deformation of sensor cells G06F3/0447)} - G06F 2203/04105: Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) ## Abstract Disclosed herein is a strain gauge including a substrate, with a first Wheatstone bridge arrangement of resistors disposed on a first surface of the substrate, and a second Wheatstone bridge arrangement of resistors disposed remotely from the first Wheatstone bridge arrangement of resistors. The resistors of the first Wheatstone bridge arrangement are equal in resistance to one another, while the resistors of the second Wheatstone bridge arrangement are unequal in resistance to one another and unequal to those of the first Wheatstone bridge arrangement. The first Wheatstone bridge arrangement of resistors are electrically connected in parallel with the second Wheatstone bridge arrangement of resistors such that each resistor of the first Wheatstone bridge arrangement is electrically connected in parallel with a different resistor of the second Wheatstone bridge arrangement. ## Claims ### Claim 1 A strain gauge, comprising: a substrate; a first Wheatstone bridge arrangement of resistors disposed on a first surface of the substrate, the resistors of the first Wheatstone bridge arrangement being equal in resistance; and a second Wheatstone bridge arrangement of resistors, some of the resistors of the second Wheatstone bridge arrangement being unequal in resistance to one another, and being unequal in resistance to the resistors of the first Wheatstone bridge arrangement of resistors; wherein the first Wheatstone bridge arrangement of resistors are electrically connected in parallel with the second Wheatstone bridge arrangement of resistors such that each resistor of the first Wheatstone bridge arrangement is electrically connected in parallel with a different resistor of the second Wheatstone bridge arrangement. ### Claim 2 (depends on 1) The strain gauge of claim 1, wherein the resistors of the first and second Wheatstone bridge arrangements are physically arranged successively next to one another along a longitudinal axis of the substrate. ### Claim 3 (depends on 1) The strain gauge of claim 1, wherein the first Wheatstone bridge arrangement of resistors comprises: a first resistor coupled between a first node and a fourth node; a second resistor coupled between the first node and a second node; a third resistor coupled between a third node and the fourth node; and a fourth resistor coupled between the second node and the third node. ### Claim 4 (depends on 3) The strain gauge of claim 3, wherein the second Wheatstone bridge arrangement of resistors comprises: a fifth resistor coupled between the first node and the fourth node; a sixth resistor coupled between the first node and the second node; a seventh resistor coupled between the third node and the fourth node; and an eighth resistor coupled between the second node and the third node. ### Claim 5 (depends on 4) The strain gauge of claim 4, wherein an output of the strain gauge is a voltage differential between potentials at the second node and the fourth node. ### Claim 6 (depends on 4) The strain gauge of claim 4 wherein the first node is connected to a supply voltage and the third node is connected to ground. ### Claim 7 (depends on 1) The strain gauge of claim 1, wherein the second Wheatstone bridge arrangement of resistors is remotely located from the first Wheatstone bridge arrangement of resistors. ### Claim 8 (depends on 1) The strain gauge of claim 1, wherein the second Wheatstone bridge arrangement off resistors is not disposed on or in the substrate. ### Claim 9 A method of measuring strain on a substrate due to force applied to the substrate, the method comprising: applying a supply voltage and a ground voltage across a pair of parallel connected Wheatstone bridge resistor arrangements, a first of the pair of Wheatstone bridge resistor arrangements being disposed on a first surface of the substrate; applying the force to the substrate; and measuring a differential voltage across output nodes of the pair of parallel connected Wheatstone bridge resistor arrangements present because the resistors of the first of the pair of Wheatstone bridge arrangements are equal in resistance while some of the resistors of a second of the pair of Wheatstone bridge arrangements are unequal in resistance. ### Claim 10 (depends on 9) The method of claim 9, further comprising, prior to application of the supply voltage and the ground voltage across the pair of parallel connected Wheatstone bridge resistor arrangements, physically arranging the resistors of the first Wheatstone bridge arrangement successively next to one another along a longitudinal axis of the substrate. ### Claim 11 An electronic device, comprising: a substrate; a first Wheatstone bridge arrangement of resistors disposed on a first surface of the substrate, the resistors of the first Wheatstone bridge arrangement being equal in resistance; and a second Wheatstone bridge arrangement of resistors disposed on a component remotely located from the substrate, some of the resistors of the second Wheatstone bridge arrangement being unequal in resistance to one another, and being unequal in resistance to the resistors of the first Wheatstone bridge arrangement of resistors; wherein the first Wheatstone bridge arrangement of resistors are electrically connected in parallel with the second Wheatstone bridge arrangement of resistors such that each resistor of the first Wheatstone bridge arrangement is electrically connected in parallel with a different resistor of the second Wheatstone bridge arrangement. ### Claim 12 (depends on 11) The electronic device of claim 11, wherein the component comprises an electronic board. ### Claim 13 (depends on 11) The electronic device of claim 11, wherein the component comprises a layer within a touch screen. ### Claim 14 (depends on 11) The electronic of claim 11, wherein the resistors of the first and second Wheatstone bridge arrangements are physically arranged successively next to one another along a longitudinal axis of the substrate. ### Claim 15 (depends on 11) The electronic device of claim 11, wherein the first Wheatstone bridge arrangement of resistors comprises: a first resistor coupled between a first node and a fourth node; a second resistor coupled between the first node and a second node; a third resistor coupled between a third node and the fourth node; and a fourth resistor coupled between the second node and the third node. ### Claim 16 (depends on 15) The electronic device of claim 15, wherein the second Wheatstone bridge arrangement of resistors comprises: a fifth resistor coupled between the first node and the fourth node; a sixth resistor coupled between the first node and the second node; a seventh resistor coupled between the third node and the fourth node; and an eighth resistor coupled between the second node and the third node. ### Claim 17 (depends on 16) The electronic device of claim 16, wherein an output of the strain gauge is a voltage differential between potentials at the second node and the fourth node. ### Claim 18 (depends on 16) The electronic device of claim 16, wherein the first node is connected to a supply voltage and the third node is connected to ground.