A magnetometer for estimating the moment of magnetic micro-particle in three dimensions

This paper presents a magnetometer for direct estimation of magnetic moment of magnetic micro-particles in three dimensions (3-D). The magnetometer consists of a force sensor that deforms in response to the magnetic interaction with the magnetic particle along with a high resolution measurement system and a nanopositioner. Novel strategies are proposed to simultaneously estimate the magnetic moment along all three axes from the measured deformation of force sensor about two independent axes. The developed setup is used to estimate the magnetic moment of magnetic particles along the three axes. In all the cases, the estimated magnetic moment agrees well with the theoretical estimates, with an average error of about 18%.