Physico-chemical milling for controlled size reduction of metal beads

Here we report a new physico-chemical method based on bipolar electrochemistry for producing spherical metal beads with a well-controlled size. Applying an electric field to a low conductivity electrolyte containing metal beads leads to a polarization potential across the beads, which triggers their electrodissolution. Upon stirring, their size decreases gradually and results in a final population which is spherical and monodisperse. Furthermore, the spherical character of shapeless particles increased to form isotropic objects. The process is versatile, self-limiting and produces beads of different final diameters depending on the applied potential. Finally, the removed material can be recycled at one of the feeder electrodes.