A magnetostatic-coupling based remote query sensor for environmental monitoring

Grimes, C. A.; Stoyanov, P. G.; Liu, Y.; Tong, C.; Ong, K. G.; Loiselle, K.; Shaw, M.; Doherty, S. A.; Seitz, W. R.

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NASA NTRS · 20040088366

A magnetostatic-coupling based remote query sensor for environmental monitoring

Grimes, C. A.·Stoyanov, P. G.·Liu, Y.·Tong, C.·Ong, K. G.·Loiselle, K.·Shaw, M.·Doherty, S. A.·Seitz, W. R.

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Abstract

A new type of in situ, remotely monitored magnetism-based sensor is presented that is comprised of an array of magnetically soft, magnetostatically-coupled ferromagnetic thin-film elements or particles combined with a chemically responsive material that swells or shrinks in response to the analyte of interest. As the chemically responsive material changes size the distance between the ferromagnetic elements changes, altering the inter-element magnetostatic coupling. This in turn changes the coercive force of the sensor, the amplitude of the voltage spikes detected in nearby pick-up coils upon magnetization reversal and the number of higher-order harmonics generated by the flux reversal. Since the sensor is monitored through changes in magnetic flux, no physical connections such as wires or cables are needed to obtain sensor information, nor is line of sight alignment required as with laser telemetry; the sensors can be detected from within sealed, opaque or thin metallic enclosures.

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NASA Discipline Life Sciences Technologies Non-NASA Center Glucose/analysis Environmental Monitoring/instrumentation Polymers Biosensing Techniques/instrumentation Magnetics Humidity Time Factors Hydrogen-Ion Concentration Equipment Design Nickel Ferric Compounds Support, U.S. Gov't, Non-P.H.S Support, U.S. Gov't, P.H.S

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Grimes, C. A., Stoyanov, P. G., Liu, Y., Tong, C., Ong, K. G., Loiselle, K., Shaw, M., Doherty, S. A., Seitz, W. R.. 1999-01-01. A magnetostatic-coupling based remote query sensor for environmental monitoring. https://ntrs.nasa.gov/citations/20040088366

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