Amino FerroMagnetic Particlesare prepared using chromium dioxide coated onto uniform polystyrene particles. These particles retain magnetism once exposed to a magnetic field. Tested and valideted for the following research areas: mechanotransduction across the cell surface and through the cytoskeleton by binding ferromagnetic particles to cell surface receptors and applying mechanical stress directly to the receptor using a device to twist the magnetic particle on the cell surface.Key fearure is that they can be demagnetized and remagnetized repeatedly and reproducibly.