# US 10,119,896 B2 · Electromechanical transducers for fluid viscosity measurement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,896 B2 - Document ID: US10119896B2 - Status: Granted - Kind: B2 - Application number: 15/384,568 - Filed: 2016-12-20 - Published: 2017-07-06 - Granted: 2018-11-06 - Earliest claimed: 2015-12-31 - Applicants: Xiang Yan - Inventors: Xiang Yan - Web page: https://patentgrep.com/patent/US10119896B2 ## CPC - G01N 11/16: by measuring damping effect upon oscillatory body - B06B 1/0603: {using a piezoelectric bender, e.g. bimorph} - G01H 13/00: Measuring resonant frequency - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - B06B: METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, {e.g.} FOR PERFORMING MECHANICAL WORK IN GENERAL (for particular applications, see the relevant subclasses, e.g. B07B1/40, B23Q17/12, B24B31/06; measurement of mechanical vibrations G01H; in direction finding, locating, distance or velocity measuring G01S; {generating seismic energy G01V1/02}; control of mechanical vibrations in general G05D; sound-producing devices, e.g. bells, sirens, whistles G10K, {e.g. methods or devices for transmitting, conducting, or directing sound in general G10K11/00}; generation of electrical oscillations H03B; electromechanical resonators in general H03H; electromechanical transducers {for communication techniques, e.g. microphones, speakers} H04R) - G01H: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES ## Abstract Electromechanical transducers and methods are disclosed for measuring fluid parameters, including viscosity and product of viscosity and density. The said transducers utilize the electromechanical transduction materials to excite and measure the vibration of composite beam(s) with sensor plate(s) attached to the end(s) of the beam(s). The fluid viscous force acted on the surfaces of the sensor plate(s) damps the beams' vibration. The voltage output or the change of the electrical conductance of the transducer can be used to measure fluid parameters. ## Claims ### Claim 1 An electromechanical transducer for measuring viscosity of a fluid, said transducer comprising: plural of parallel composite beams of identical length, where each composite beam is comprised of one substrate sandwiched between two electromechanical transduction materials, wherein said composite beams are attached to a common supporting structure at one end and are rigidly connected together at the other end with at least one sensor plate attached at this end; wherein the normal direction of the said sensor plate is orthogonal to the normal direction of the said composite beams; and a recess on the sensor plate controlling the immersion depth in the fluid. ### Claim 2 (depends on 1) An electromechanical transducer according to claim 1, wherein a drive circuit capable of frequency sweeping is used to drive the two electromechanical transduction materials as a mean to excite bending vibration of the plural composite beams with amplitude anti-node at the end of the sensor plate. ### Claim 3 (depends on 1) An electromechanical transducer according to claim 1, wherein the said plural composite beams vibrate in phase. ### Claim 4 (depends on 1) An electromechanical transducer according to claim 1, wherein the voltage generated from separate plural electromechanical transduction materials is measured as output. ### Claim 5 (depends on 1) An electromechanical transducer according to claim 1, wherein the two electromechanical transduction materials used for vibration excitation can be from one or separate composite beams. ### Claim 6 (depends on 1) An electromechanical transducer according to claim 1, wherein the two electromechanical transduction materials used for output voltage generation can be from one or separate composite beams. ### Claim 7 (depends on 1) An electromechanical transducer according to claim 1, wherein the two electromechanical transduction materials used for vibration excitation are polarized in the same direction and are electrically connected in parallel to admit the input voltage. ### Claim 8 (depends on 1) An electromechanical transducer according to claim 1, wherein the two electromechanical transduction materials used for output voltage generation are polarized in the opposite direction and are electrically connected in series. ### Claim 9 (depends on 1) An electromechanical transducer according to claim 1, when an alternating electrical input signal is used to drive the two electromechanical transduction materials as a mean to excite a bending vibration of the said plural of composite beams, an alternating electrical output signal is generated from separate the two electromechanical transduction materials having an amplitude and phase relationship to the input signal that can be used to determine the viscosity of the fluid. ### Claim 10 (depends on 1) An electromechanical transducer according to claim 1, where the two electromechanical transduction materials from said plural of parallel composite beams are polarized in the same direction and are electrically connected in parallel such that when an alternating electrical signal is applied to the two electromechanical transduction materials, said plural of parallel composite beams are excited into a bending vibration whose conductance can be used to determine the viscosity of the fluid. ### Claim 11 A method of obtaining viscosity of a fluid utilizing a transducer having a composite beam made of a substrate sandwiched between two electromechanical transduction materials, a supporting structure and a sensor plate attached to opposite ends of the composite beam, wherein the normal directions of the sensor plate and the composite beam are orthogonal to each other, a recess on the sensor plate controlling the immersion depth in the fluid, comprising: inputting an alternative voltage to one electromechanical transduction material to set up bending vibration of the composite beam; outputting an alternative voltage from second electromechanical transduction material; and deriving viscosity of the fluid from the product of the frequency and the ratio of output to input voltages at the resonance of the vibration.