Nanotechnology involves controlling and manipulating matter at the atomic and molecular scales, generally 100 nanometers or smaller. It has a wide range of potential applications but also raises concerns about environmental and health impacts. The term was coined in the 1970s but the concepts date back to Richard Feynman's 1959 talk about manipulating atoms and molecules. Research has accelerated in recent decades due to new technologies like scanning tunneling microscopes that allow viewing and manipulating structures at the nanoscale.