Why !!
http://www.drive.com.au/editorial/article.aspx?id=10647&vf=4&bg=24&pp=0
Scientists at Rice University in Texas have won the race to build the world's smallest car. It's called the nanocar, which ought to give a clue about its size. They say it is the world's first single-molecule vehicle and is built using nano-technology.
It has a chassis, pivoting axles and rotating wheels and measures three to four nanometres across, making it slightly wider than a strand of DNA. To put it in perspective, a human hair is about 80,000 nanometres in diameter. So in the width of a human hair you could place about 20,000 nanocars end to end. That's small.
The nanocar is described in a research paper from the university, which says the synthesis and testing of nanocars and other molecular machines is "providing critical insight in our investigations of bottom-up molecular manufacturing".
Professor James M. Tour, of the university's departments of chemistry, mechanical engineering, materials science and computer science, says: "We'd eventually like to move objects and do work in a controlled fashion on the molecular scale and these vehicles are great test beds for that. They're helping us learn the ground rules."
The nanocar is capable of rolling on its wheels in a direction at right angles to its axles and was tested by rolling it across a gold surface. At room temperature, strong electrical bonds held the wheels tightly against the gold but heating to about 200C freed them to roll.
Tour's research group has spent almost eight years perfecting the techniques used to make the nanocar and it is now working on a light-driven nanocar and a nanotruck that can carry a payload.
