Microfluidics provides exciting possibilities for miniaturized biosensors systems allowing for highly parallel automated high throughput tests to be performed. Detection of low concentrations of bacteria, viral particles and parasites in food samples is a challenging process. The capture of the target can be more effectively carried out with efficient mixing. We present a simple microfluidic system capable of controlled transport of rotating magnetic beads among soft magnetic patterns. Low aspect ratio NiFe discs (200 nm tall, diameter 3 μm) are patterned onto a silicon wafer. A PDMS channel is bonded onto the wafer to create the microfluidic channel. An external permanent magnet attached to a motor provides a magnetic field, which can be rotated at different speeds while magnetizing the NiFe disks in the channel. Microbeads (Dynabeads M-280, Invitrogen) introduced into the channel with a syringe pump are trapped at the poles of the now magnetized soft magnetic discs. Rotation of the external permanent magnet induced magnetic poles in the soft magnetic discs which will in turn rotate the trapped microbeads. We have already demonstrated the capacity to capture particles from flow with rotating M-280 beads in this device.
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