An artificial cartilage was invented based on JOINT-ELECTRICITY THEORY that first in the world created in 2010, and verified in 2011, both by the present inventor, Sue-May Kang. The said artificial cartilage has sleek joint-surface and individualized appropriate shape, is made of proper piezoelectric material, and to be placed into the indication-joints, including at least the natural joints with lack or defect in cartilage and artificial joints, those suffering from impairment in generating Joint-Electricity. After surgical placement (yet, any surgery is not included in the present invention), it can be subjected to the dynamic force within the said joint in its effective range, and thus, continuously generate intra-articular electricity (is the so-called Joint-Electricity), and consequently supplements the wanted Joint-Electricity to the said joint and its related muscles. Using the said artificial cartilage can remarkably reduce the pains, increase muscular strength, and improve motor functions, when comparing to that without.
