The invention relates to an extrusion head and a method with which the thickness distribution of hollow bodies, for example, can be further improved. Poly containing ferrocene is prepared by dissolving ferrocene corresponding to 1 to 3 wt % on the iron atomic basis in furfuryl alcohol, adding hydrochloric acid thereto as a polymerization initiator, and then polymerizing them in the air at 70\xb0 C. In some embodiments, the characteristic improvement material includes at least one of a negative stiffness material or a negative Poisson’s ratio material. When a spacer is created on the polysilicon shape, the spacer width is formed to be small enough near the bridging vertex to allow a silicide bridge to form that creates an electrical coupling between the silicon area and the bridging vertex. Once a particular character is activated, game play proceeds according to preset rules.