The history of wireless charging technology
As early as 1830s, Michael Farad discovered that changes in the surrounding magnetic field would generate electricity in wires. In 1890s, Edison, an assistant of the spectral radiation research project of Nicola Tesla, applied for the first patent.
Unfortunately, the research in this area has been delayed for a century. The biggest obstacle is that the transmission efficiency is too low and dangerous. Electromagnetic radiation is only suitable for transmitting information, and is not suitable for transmitting energy. Because radiation is nondirective, energy will be wasted in useless space. Some people think that using directional electromagnetic radiation, such as laser, is not operational and dangerous.
Professor Xu Shuyuan of the Department of electronic engineering of City University Hong Kong has successfully developed a "battery charging platform" in the past few years. It can put several electronic products on a charging platform without external wires and charge automatically through low frequency electromagnetic field. The charging time is not the same as that of the traditional charger. But this technology still needs the contact between the product and the charger. It mainly uses the principle of near-field electromagnetic coupling.