Development of CD Based Micro-Fluidics Device for High Throughput Particle Capture and Sampling

A key challenge in biosensing is the capture of a target from a complex matrix. We are investigating methods to improve sampling and pre-concentration through efficient bead-based manipulation using magnetic fields. We present work on development of centrifugal micro-fluidic system for high throughput capture of fluorescent microparticles. The setup employs a disc consisting of an array of circular NiFe magnetic features that are axially symmetric. Sample is driven along numerous axially symmetric micro-channels in a radially outward direction. This pumping occurs under the influence of the centrifugal force created by the rotating disc. Super-paramagnetic beads are first introduced into the rotating device and are manipulated by a uniform external magnetic field. This enables the bead rotation around the magnetic features, thereby enhancing the mixing in the device. This setup is novel in that, it enables continuous high volume sampling and does not require external pumps/valves for fluid handling. The rotating disc enables both the pumping of fluid and bead rotation.