What is energy harvesting?
Where there is movement and friction, there is also energy. Harnessing this energy is the basic principle of “energy harvesting”. Energy harvesting eliminates the need for cables to supply power or recharge batteries in mobile devices. Vibrations in devices, machines, or buildings, or temperature differences between tubes, cables, radiators, or valves and the environment can be used to generate electrical energy.
You can find out the extent to which the industry is taking advantage of this principle here: https://blog.igus.de/energy-harvesting-power-durch-reibung/