Title :
Bead Capture on Magnetic Sensors in a Microfluidic System
Author :
Østerberg, Frederik W. ; Dalslet, Bjarke T. ; Damsgaard, Christian D. ; Freitas, Susana C. ; Freitas, Paulo P. ; Hansen, Mikkel F.
Author_Institution :
Dept. of Micro & Nanotechnol., Tech. Univ. of Denmark (DTU Nanotech), Lyngby
fDate :
6/1/2009 12:00:00 AM
Abstract :
The accumulation of magnetic beads by gravitational sedimentation and magnetic capture on a planar Hall-effect sensor integrated in a microfluidic channel is studied systematically as a function of the bead concentration, the fluid flow rate, and the sensor bias current. It is demonstrated that the sedimentation flux is proportional to the bead concentration and has a power law relation to the fluid flow rate. The mechanisms for the bead accumulation are investigated and it is found that gravitational sedimentation dominates the bead accumulation, whereas the stability of the sedimented beads against the fluid flow is defined by the localized magnetic fields from the sensor.
Keywords :
Hall effect devices; biosensors; disperse systems; flow sensors; magnetic sensors; microchannel flow; sedimentation; Microfluidic System; bead capture; fluid flow rate; gravitational sedimentation; magnetic beads; magnetic capture; magnetic fields; magnetic sensors; microfluidic channel; planar Hall-effect sensor; sensor bias current; Biosensors; Fluid flow; Hall effect devices; Magnetic flux; Magnetic levitation; Magnetic sensors; Microfluidics; Nanotechnology; Sensor systems; Stability; AMR; bead; biosensor; lab-on-a-chip; micro fluidic;
Journal_Title :
Sensors Journal, IEEE
DOI :
10.1109/JSEN.2009.2021122
