As an example of the growing use of solar power, the Shiken Company, based in Japan, is developing a solar-powered toothbrush. The device features a solar panel in its base that produces about the same amount of power that a traditional solar calculator would. The designers say that electrons generated by the solar panel are pushed to the top of the brush where they react with mouth acids to create a chemical reaction that can destroy bacteria and break down plaque at the same time.