Scientists at the VTT Technical Research Centre of Finland have demonstrated a new technique for harvesting energy from mechanical vibrations of the environment and converting it into electricity. They explain that energy harvesters are needed, for example, in wireless self-powered sensors and medical implants, such as pacemakers, where they could ultimately replace batteries.

The researchers successfully generated energy by utilizing the charging phenomenon that occurs naturally between two bodies with different work functions (the amount of energy needed to remove an electron from a solid). When two conducting bodies with different work functions are connected to each other electrically, they accumulate opposite charges.

Moving these bodies with respect to each other generates energy because of the attractive electrostatic force between their opposite charges. In this research, the energy generated by this motion was converted into electrical power by connecting the bodies to an external circuit.

In many sensor applications and medical implants such as pacemakers, electricity is typically provided by batteries. This technique does not require an integrated battery or piezo materials.

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