Executive Summary : | A new microfluidic system is being developed for the detection of magnetic microbeads for biomedical applications. The system is built on an existing high-sensitivity planar Hall effect-based magnetic field sensor, which has a field detection threshold of 5nT and a best-in-class sensitivity of 650Ω/T under DC open-loop conditions. The system will use this high sensitivity to detect small numbers of functionalized magnetic microbeads that attach themselves to the sensor surface if a specific target molecule is present in solution. The system will undergo several steps, including ac lockin detection, closed loop operation, and on-chip ac dynamic susceptibility measurement, which are expected to increase sensitivity by at least a factor of 10. This could lead to a significant reduction in the cost of detection of clinically relevant biomolecules without compromising sensitivity. |