Microfluidic device for biocells manipulation and measurement

In this work we present a study of the interaction between the magnetic particles used in biological applications and the GMR sensor. The fractional change in resistance, and hence the sensitivity, will be maximized by matching, as far as possible, the size of the sensor to the size of the beads and by carefully positioning the beads over the sensor. We found, by micromagnetic simulations, that the amount of the surface coverage with magnetic particles may affect the magnetization curve of the sensor and will change the field dependence of his GMR response.