Nanotechnology involves engineering materials at the nanoscale, around 1 to 100 nanometers. Richard Feynman is considered the father of nanotechnology. Nanotechnology has applications in many fields including electronics, computing, medicine, cosmetics, foods, the military, and energy. By 2020, products with nanotechnology components could be worth $1 trillion. Materials behave differently at the nanoscale compared to larger scales due to statistical mechanics and quantum effects. Nanotechnology is approached through top-down methods like lithography or bottom-up methods like self-assembly.