University of Kentucky Research Foundation

Dimitris Kouzoudis

Craig A Grimes

Leonidas G Bachas

Plamen G Stoyanov

Stefan Schmidt

Gary Barrett

An apparatus for determining elasticity characteristics of a thin-film layer. The apparatus comprises a sensor element having a base magnetostrictive element at least one surface of which is at least partially coated with the thin-film layer. The thin-film layer may be of a variety of materials (having a synthetic and/or bio-component) in a state or form capable of being deposited, manually or otherwise, on the base element surface, such as by way of eye-dropper, melting, dripping, brushing, sputtering, spraying, etching, evaporation, dip-coating, laminating, etc. Among suitable thin-film layers for the sensor element of the invention are fluent bio-substances, thin-film deposits used in manufacturing processes, polymeric coatings, paint, an adhesive, and so on. A receiver, preferably remotely located, is used to measure a plurality of values for magneto-elastic emission intensity of the sensor element in either characterization: (a) the measure of the plurality of values is used to identify a magneto-elastic resonant frequency value for the sensor element; and (b) the measure of the plurality of successive values is done at a preselected magneto-elastic frequency.

Magnetoelastic sensor for characterizing properties of thin-film/coatings

A pressure sensing apparatus for operative arrangement within an environment, having: a sensor comprising a hermetically-sealed receptacle, at least one side of which has an flexible membrane to which a magnetically hard element is attached. Enclosed within the receptacle is a magnetostrictive element that vibrates in response to a time-varying magnetic field. Also included is a receiver to measure a plurality of successive values for magneto-elastic emission intensity of the sensor taken over an operating range of successive interrogation frequencies to identify a resonant frequency value for the sensor. Additional features include: (a) the magnetically hard element may be adhered to an inner or outer side of, or embedded within, the membrane; (b) the magnetostrictive element can include one or more of a variety of different pre-formed, hardened regions; (c) the magneto-elastic emission may be a primarily acoustic or electromagnetic emission; and (d) in the event the time-varying magnetic field is emitted as a single pulse or series of pulses, the receiver unit can detect a transitory time-response of the emission intensity of each pulse (detected after a threshold amplitude value for the transitory time-response is observed). A Fourier transform of the time-response can yield results in the frequency domain. Also, an associated method of sensing pressure of an environment is included that uses a sensor having a magnetostrictive element to identify a magneto-elastic resonant frequency value therefore. Using the magneto-elastic resonant frequency value identified, a value for the pressure of the environment can be identified.

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Thessaloniki, Greece

Dimitris Kouzoudis