a center magnetic pole aligned with two outer magnetic poles;

two conductive cantilevers comprising at a supported end of each cantilever, two legs electrically isolated from the poles, the legs supported opposite each other across the center pole and between the outer poles, wherein a sample zone is defined as the area between opposing faces of the cantilevers, a magnetic field produced by the center magnetic pole and outer magnetic poles having magnetic vectors in opposite directions across each leg, the sample zone adapted to receive a small sample to be analyzed;

an electric current flowing in opposite directions through the two legs, the interaction between the magnetic vectors and the electric current causing an imposed force on the two legs; and

at least one displacement sensor directed to the conductive cantilevers; and a controller that:

is electrically coupled to the legs of each cantilever to independently apply the current to each cantilever and correlate the current with the force at each cantilever; and

is coupled to the displacement sensor to independently correlate the displacement of each cantilever with the force at each cantilever; and

comprises a feedback control loop that dynamically controls the displacement of a sample in the sample zone.