More recently, the phrase has taken on a different meaning as scientists and engineers develop nanotechnology - processes to control matter at an atomic or molecular level - and show that this field, too, can promote sustainable development.
Nowhere is the promise of nanotechnology stronger than in water treatment. Nanofiltration techniques and nanoparticles can reduce or eliminate contaminants in water and could help deliver a key Millennium Development Goal - halving the proportion of people without sustainable access to safe drinking water by the year 2015.
The challenges are many, and not just technical. Some relate to health and safety, and the need for appropriate regulations to defend both. And some are more political, for example the need to make basic technologies both accessible to and controllable by the communities that need them most. Like any new technology, community acceptance is essential if nanotechnology is to effectively work in villages across the developing world, where water problems are often the most acute.