A Nano Lesson

I'm quite bald, but a single hair on that tousled head of yours is over 50,000 nanometres wide. And if you're 6 feet tall, you're about 1,830,000,000 nanometres in length! So a nanometre (nm), is one billionth of a metre, or one millionth of a millimetre. It is a measure of length, on the scale of atoms and molecules. And nanotechnology is any application of science that deals with elements--usually processes, materials, and device structures used to build transistors or circuit elements--betwixt 100 nm and one tenth of an nm in size, in which size is critical to the applications ultimate purpose. So in essence, nanotechnology deals with the manipulation of atoms--the very building blocks for all matter in our universe--and is a catch-all word for activities at the level of atoms and molecules that have applications in the real world. Nanotechnology is a hybrid science which combines engineering and chemistry. And it is also being regarded as the next rational step for advancement in computer architecture.

However, over the last few years, nanotech has come to mean two different things. It is now often used interchangeably with molecular nanotechnology (MNT). Originally, the term nanotechnology was invented by Norio Taniguchi of Tokyo Science University in 1974 to describe physicist Richard Feynman's vision of precision manufacture of materials with nanometre tolerances. In the 1980s the term was reinvented by K. Eric Drexler to molecular nanotechnology. MNT is a highly advanced form of nanotechnology that scientists globally are working towards. It envisions machines--motors, robotic arms, and even computers--built on the scale of molecules that a few nanometres wide.

The two fundamentally different approaches to nanotechnology are graphically called 'top down' and 'bottom up'. Top-down means constructing nano structures using machining and etching techniques. Bottom-up, or MNT, applies to building organic and inorganic structures atom-by-atom, or molecule-by-molecule.

Nanotech applications are multiple and their uses nothing short of ingenious. From miniaturising computers, to building super stronger materials, to high power-density motor-generators that operate at high frequencies, to purification of water, to harnessing solar energy. But perhaps the most invaluable and immediate use of nanotechnology will in medicine. Think of a nano-medical device (called an intelligent drug delivery systems) that can travel inside the human body to seek and destroy pathogens and cancerous cells-even before they can multiply! That's not it: Regenerative medicine, nanorobots in surgery, nanomedical imaging and contrast agents, nanotechnology and stem cell research, 'point of care' devices, nanoparticle toxicology... the list is virtually endless. And the story has just begun.