In 2004, concerns over the potential health, environmental, social, ethical, and regulatory issues associated with nanotechnology surfaced. The concerns, however, did slow down new discoveries. In 2007, Angela Belcher and researchers at MIT built a lithium-ion battery with a common type of virus that is nonharmful to humans, using a low-cost and environmentally friendly process. The batteries have the same energy capacity and power as other rechargeable batteries. They are being considered to power plug-in hybrid cars and could be used to power other personal electronics.