The principle of magnetic insole is to stimulate acupoints with bionic magnets, which has the magical effect of keeping fit and growing tall and thin legs. In some cases, static electricity can be generated without friction, such as induced electrostatic electrification, thermoelectric and piezoelectric electrification, Helmholtz layer, jet electrification and so on. Any two objects with different materials will generate static electricity after being separated, and the common method to generate static electricity is friction electrification. The better the insulation of the material, the easier it is to generate static electricity. Because air is also composed of atoms, it can be said that static electricity may be generated at any time and place in people's lives. It is almost impossible to completely eliminate static electricity, but some measures can be taken to control static electricity so that it does not cause harm. Reason: Everything is made up of atoms, and the basic structures of atoms are protons, neutrons and electrons. Scientists define protons as positively charged, neutrons as uncharged and electrons as negatively charged. Under normal circumstances, an atom has the same number of protons and electrons, and the positive and negative charges are balanced, so it is not charged. However, due to external effects such as friction or in the form of kinetic energy, potential energy, thermal energy and chemical energy, the positive and negative charges of atoms will be unbalanced. Friction in daily life is essentially a process of constant contact and separation.