Controlled trapping and detection of magnetic particles by a magnetic microactuator and a giant magnetoresistance (GMR) sensor

Ioanna Giouroudi, Chinthaka Pasan Gooneratne, Georgios Kokkinis

Research output: Chapter in Book/Report/Conference proceedingConference contribution


This paper presents the design and testing of an integrated micro-chip for the controlled trapping and detection of magnetic particles (MPs). A unique magnetic micro-actuator consisting of square-shaped conductors is used to manipulate the MPs towards a giant magnetoresistance (GMR) sensing element which rapidly detects the majority of MPs trapped around the square-shaped conductors. The ability to precisely transport a small number of MPs in a controlled manner over long distances by magnetic forces enables the rapid concentration of a majority of MPs to the sensing zone for detection. This is especially important in low concentration samples. The conductors are designed in such a manner so as to increase the capture efficiency as well as the precision and speed of transportation. By switching current to different conductors, MPs can be manipulated and immobilized on the innermost conductor where the GMR sensor is located. This technique rapidly guides the MPs towards the sensing zone. Secondly, for optimum measurement capability with high spatial resolution the GMR sensor is fabricated directly underneath and all along the innermost conductor to detect the stray fields originating from the MPs. Finally, a microfluidic channel is fabricated on top of this micro-chip. Experiments inside the microchannel were carried out and the MPs were successfully trapped at the sensing area. © (2014) Trans Tech Publications.
Original languageEnglish (US)
Title of host publicationKey Engineering Materials
PublisherTrans Tech Publications
Number of pages4
ISBN (Print)9783038350514
StatePublished - Apr 2014

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01

ASJC Scopus subject areas

  • Mechanics of Materials
  • General Materials Science
  • Mechanical Engineering


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