President Bush on Wednesday signed legislation to fund nanotechnology research and development for four years starting next Oct. 1. The 21st Century Nanotechnology Research and Development Act puts on the books programs and activities already supported by the National Nanotechnology Initiative, a major administration R&D priority.

Even before the law takes effect, the president had requested $849 million for nanotechnology R&D across 10 federal agencies this fiscal year, a 10% increase from last year's levels.

The White House sees nanotechnology as providing a breakthrough to revolutionize the way people detect and treat disease, monitor and protect the environment, produce and store energy, and build complex structures as small as an electronic circuit or as large as an airplane. The administration says it expects nanotechnology to have a broad and fundamental impact on many sectors of the economy, leading to new products, businesses, jobs, and industries.

Nanotechnology is the ability to work at the atomic and molecular levels, corresponding to lengths of 1/100,000th the diameter of a human hair. Nanotechnology is not merely the study of small things, the administration says, but includes the research and development of materials, devices, and systems that exhibit physical, chemical, and biological properties that are different from those found at larger scales.