# US 2025/0035666 A1 · Shear mode piezoelectric accelerometer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0035666 A1 - Document ID: US20250035666A1 - Status: Published application - Kind: A1 - Application number: 18/457,919 - Filed: 2023-08-29 - Published: 2025-01-30 - Earliest claimed: 2023-07-26 - Assignees: National Cheng Kung University - Applicants: National Cheng Kung University - Inventors: Cheng-Ying LI; Sheng-Yuan CHU - Web page: https://patentgrep.com/patent/US20250035666A1 ## CPC - G01P 15/0915: {of the shear mode type} - G01P 1/023: {for acceleration measuring devices} - G01P 15/18: in two or more dimensions - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) ## Abstract A shear mode piezoelectric accelerometer includes a ring-shaped piezoelectric element, a central shaft, a mass block, a first electrode, and a second electrode. The ring-shaped piezoelectric element includes an outer ring wall and an inner ring wall. The central shaft is made of conductive material and is fixed through the inner ring wall of the ring-shaped piezoelectric element. The mass block is made of conductive material and includes a fixed element and a weight element. The fixed element has a fixed hole and is fixed to the outer ring wall of the ring-shaped piezoelectric element by fitting the fixed hole. The weight element is located on the fixed element on the opposite side away from the fixed hole. The first electrode is electrically connected to the central shaft. The second electrode is electrically connected to the mass block. ## Claims ### Claim 1 A shear mode piezoelectric accelerometer, comprising: a ring-shaped piezoelectric element, comprising an outer ring wall and an inner ring wall; a central shaft, made of conductive material and fixed through the inner ring wall of the ring-shaped piezoelectric element; a mass block, made of conductive material and comprising a fixed element and a weight element, the fixed element having a fixed hole and being fixed to the outer ring wall of the ring-shaped piezoelectric element by fitting the fixed hole, and the weight element being located on the fixed element on the opposite side away from the fixed hole; a first electrode, electrically connected to the central shaft; and a second electrode, electrically connected to the mass block, wherein the weight element of the mass block rotates relative to the central shaft, whereby the ring-shaped piezoelectric element is deformed and a potential difference is generated between the first electrode and the second electrode. ### Claim 2 (depends on 1) The shear mode piezoelectric accelerometer according to claim 1, further comprising a body having a housing groove in which the ring-shaped piezoelectric element, the central shaft, and the mass block are housed. ### Claim 3 (depends on 2) The shear mode piezoelectric accelerometer according to claim 2, wherein the housing groove comprises an opening, the weight element being exposed outside the opening. ### Claim 4 (depends on 2) The shear mode piezoelectric accelerometer according to claim 2, wherein the body has a retaining wall, the retaining wall being located on a bottom surface of the housing groove, and the weight element abutting against the retaining wall. ### Claim 5 (depends on 2) The shear mode piezoelectric accelerometer according to claim 2, wherein the body is made of insulating material. ### Claim 6 (depends on 1) The shear mode piezoelectric accelerometer according to claim 1, wherein the fixed element has a notch located on the side opposite to the weight element. ### Claim 7 (depends on 1) The shear mode piezoelectric accelerometer according to claim 1, wherein the fixed element and the weight element are made of different materials, and the fixed element is made of conductive material. ### Claim 8 (depends on 1) The shear mode piezoelectric accelerometer according to claim 1, wherein the weight element extends outward from the fixed element along a radial direction of the central shaft. ### Claim 9 (depends on 1) The shear mode piezoelectric accelerometer according to claim 1, further comprising a processing unit connected to the first electrode and the second electrode respectively and generating a corresponding acceleration value according to the potential difference. ### Claim 10 (depends on 1) The shear mode piezoelectric accelerometer according to claim 1, wherein the ring-shaped piezoelectric element is circular or C-shaped.