Nanowire-GMR integrated microfluidic biosensor

Ramya Bellamkonda, Tom John, Bobby Mathew, Hisham Hegab, Mark DeCoster, Despina Davis

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

1 Citation (Scopus)


Nanowires based GMR is ideal to be integrated in microfluidic devices due to its efficient detection of sensitive magnetic fields. Nanowire based GMR microfluidic sensor is used to detect different fluids based on their magnetic behavior. This paper demonstrates the fabrication and testing of nanowire based GMR biosensors with four different control solutions: 1) DI-water, 2) Phosphate Buffered Saline (PBS), 3) polystyrene superparamagnetic beads, and 4) commercially available magnetic Dynabeads. The device is fabricated in PDMS by using a lithographically patterned silicon wafer as the mold. The nanowire based GMR material, 3 mm by 3 mm in size, is inserted inside the PDMS close to the channel during the fabrication. The channel in the PDMS substrate is sealed by bonding it to a glass plate using Reactive-Ion-Exchanger (RIE). GMR device is tested potentiostatically using a computer controlled function generator (Solatron, SI 1287). A highest resistance of 0.748 ω is recorded for the sensor, in the absence of magnetic field. A resistance change of 0.6% is obtained in the presence of a magnetic field (B=0.035T) between water and polystyrene superparamagnetic beads when pumped through the microchannel. The sensor showed a resistance difference of 0.31% between IX diluted PBS and 100X diluted dynabeads, in the presence of a constant magnetic field of 0.035T. This characterization would be useful in the development of a BioMEMS sensor using nanowire based GMR.

Original languageEnglish
Title of host publicationProceedings of the ASME Fluids Engineering Division Summer Conference 2009, FEDSM2009
Number of pages4
Publication statusPublished - 2009
Externally publishedYes
Event2009 ASME Fluids Engineering Division Summer Conference, FEDSM2009 - Vail, CO, United States
Duration: Aug 2 2009Aug 6 2009

Publication series

NameProceedings of the ASME Fluids Engineering Division Summer Conference 2009, FEDSM2009


Conference2009 ASME Fluids Engineering Division Summer Conference, FEDSM2009
Country/TerritoryUnited States
CityVail, CO

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes
  • Mechanical Engineering


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