Our ability to work at the nanoscale -- using new tools to observe atoms, manipulate molecules, and build structures -- is advancing rapidly. A few days ago, we reported on the success of scientists at Rice University in constructing a nanoscale car. This is an excellent example of building "from the bottom up," precisely combining atoms to make working machines.
Another approach to building nanoscale structures is "from the top down."
The University of Pittsburgh recently became the only institution in the United States and only the second in the world to have a unique nanofabrication capability. . . The eLiNE system allows researchers to create nanometer-scale structures using an electron beam that is focused to less than two nanometers. A unique feature of this instrument is an electron beam-induced deposition and etching capability that allows metals, insulators, and semiconductors to be added or removed, using the electrons as a nanocatalyst.
Using this remarkable tool, Pitt scientists have created the world's smallest chess pieces, approximately 400 nanometers wide.
The device uses five small capillaries — hollow injection needles — to add specific gases and materials to a small surface. Then a small beam of electrons acts to help these gases interact with the object to shape it. . . The electron beam can be focused to a diameter of two nanometers, or about twice the distance between two atoms in a solid object.
"In a sense, it's like having a machine shop, only a million times smaller," said Jeremy Levy, Pitt professor of physics and astronomy.
Levy said that the possibilities of this technology include building incredibly small conductors, since the workstation can 'etch' wires 10 nanometers in diameter onto a surface.
Although this new top-down technology is quite impressive, it is not quite atomically precise, not yet. But it's fascinating to see how quickly the two approaches are coming together. The time when tiny machines will work together inside a nanofactory to make amazing products is not far away.
One final note:
The Rice team has already followed up the nanocar work by designing a light-driven nanocar and a nanotruck that's capable of carrying a payload."The synthesis and testing of nanocars and other molecular machines is providing critical insight in our investigations of bottom-up molecular manufacturing," said one of the two lead researchers, James M. Tour, the Chao Professor of Chemistry, professor of mechanical engineering and materials science, and professor of computer science.
Tags: nanotechnology nanotech nano science technology ethics weblog blog
Me, I'm still waiting for advances in microelectromechanical scanning probe instruments. It would be nice to have vast swarms of micron sized scanning probe microscopes building molecules in tandem. If silicon foundries could blast zillions these on a silicon wafer with photolith, then we'd be getting somewhere.
It took the Rice team 8 years to figure out clever chemistry to reliably make the nanocars. That's just too long to be useful. I read recently that Dartmouth recently built a tiny robot that was untethered and mobile. We need to do more of that.
Posted by: Pace Arko | October 24, 2005 at 06:08 PM
Progress will speed, as with most technology, we will see more frequent breakthroughs as a result of the previous one. The collection of knowledge that we are building will only make progress faster and definitly not slower or at the same pace.
Posted by: Matt | October 25, 2005 at 12:47 AM