Nanotechnology involves controlling and manipulating matter at the nanoscale to create new materials and devices. It has applications in medicine such as creating precise surgical instruments that could operate at the cellular and molecular level. Nanorobots less than 100 nanometers could be used for medical applications like delivering oxygen to tissues or removing blood clots and viruses. While promising, nanotechnology may also lead to environmental problems if nanoparticles interact harmfully with the environment.