A Japanese research team elucidated the microscopic mechanism in which amorphous silica becomes negatively charged as a vibrational energy harvester, which is anticipated to achieve self-power generation without charging, as it is needed for IoT that is garnering attention in recent years with its 'trillion sensors' that create a large-scale network of sensors. Unlike wind power and solar power generation, vibrational power generation, which utilizes natural vibration for power generation, is not affected by weather.