Remotely queried magnetoacoustic sensors for monitoring starch concentrations, pH, and polymer curing

Huqun Liu; William Rudolf Seitz; Craig A. Grimes; Keat Ghee Ong; P. G. Stoyanov

doi:10.1117/12.417444

26 February 2001 Remotely queried magnetoacoustic sensors for monitoring starch concentrations, pH, and polymer curing

Huqun Liu, William Rudolf Seitz, Craig A. Grimes, Keat Ghee Ong, P. G. Stoyanov

Proceedings Volume 4205, Advanced Environmental and Chemical Sensing Technology; (2001) https://doi.org/10.1117/12.417444
Event: Environmental and Industrial Sensing, 2000, Boston, MA, United States

Abstract

Although acoustic wave sensors that use piezoelectricity have many advantages, all of them need electrical connections to excite the piezoelectric crystals with an alternating voltage. This paper presents a new type of continuously operating, in-situ, and remotely monitored sensor that doesn't require electrical connections. The new sensor is comprised of a magnetoelastic metallic glass ribbon. Its sensing principle is similar to acoustic wave sensors. An externally applied alternating current (ac) magnetic field is used to excite magnetoelastic waves inside the magnetoelastic thin ribbon. Frequency responses are monitored with a pickup coil located outside the test area and the resonant frequencies are measured. The sensor responds to mass loading as a microbalance by decreasing its resonant frequency. When immersed in liquid, its resonant frequency is correlated with the square root of the product of liquid viscosity and density. We studied the relationship between the frequency shift and the square root of the product of viscosity and density of a starch solution. We found that the frequency shift was linearly proportional to the starch concentration. After bonding a poly-hydroxyethyl acrylate (poly-HEA) membrane to the magnetoelastic ribbon, the sensitivity of the sensor to water loading was greatly increased. The new sensor has also been used to monitor polymer curing. After bonding the ribbon with a pH sensing membrane, it was used to monitor pH. Because the sensor does not require electrical connections, it can remotely monitor concentrations in situ in a sealed container.

Citation Download Citation

Huqun Liu, William Rudolf Seitz, Craig A. Grimes, Keat Ghee Ong, and P. G. Stoyanov "Remotely queried magnetoacoustic sensors for monitoring starch concentrations, pH, and polymer curing", Proc. SPIE 4205, Advanced Environmental and Chemical Sensing Technology, (26 February 2001); https://doi.org/10.1117/12.417444

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available