Two dimensional system of several millimeter size spheres using triboelectrification

Two dimensional crystal is tested in the system of several millimeter size polystyrene spheres. Large numbers of same size spheres are triboelectrical ly charged through rubbing on the substrate plate. Therefore, one can obser ve the two dimensional system without the help of any instrument and can ea sily micro-control the condition of two dimensional system. The pair distri bution function and the bond-orientational correlation function of the syst em are measured to study the symmetry and the structure of the system. We h ave observed a near hexatic phase predicted by the KTHNY theory.