Information technology and biotechnology are so five minutes ago. The technology of the future, the one which governments and companies all over the world are betting on, is nanotechnology.
Nanotechnology promises breakthroughs that will revolutionise the way we 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 aeroplane. It will have a fundamental impact on many sectors of the economy, leading to new products, new businesses, new jobs, and even new industries.
In the words of Neal Lane, director of the White House Office of Science and Technology Policy under Bill Clinton, “If I were asked for an area of science and engineering that will most likely produce the breakthroughs of tomorrow, I would point to nanoscale science and engineering.”
But despite the hullabaloo in board rooms and universities, nanotechnology is a mystery to most people. What is it all about? Basically, it is the ability to work at the atomic and molecular levels, corresponding to lengths of approximately 1 to 100 nanometres, or 1/100,000th the diameter of a human hair. It is not merely the study of small things; it is the research and development of materials, devices, and systems with different physical, chemical, and biological properties of larger objects.
A hairy business
To understand the dimensions of the materials nanotechnologists work with, consider a person who stands two meters tall looking down on an ant two millimeters long. Imagine that the ant could see a red blood cell that is two micrometers long — a micrometer is one thousandth of a millimeter. That ant looking at the red blood cell is like the person looking down on the ant. But the ant would still need a powerful set of lenses to marvel at the sight of three atoms whose combined sizes make up a nanometer.
How big is a nanometer? Dr Mahendra Sunkara, associate professor of chemical engineering at the University of Louisville’s Speed Scientific School says that 100,000 nanometres would fit across the diameter of a human hair.
By altering the atomic configurations of known substances, nanotechnologists yield devices useful in everything—from medicine to data storage to the speed with which a desktop or a notebook does word processing. “Nanotechnology is harnessing the new properties of matter that appear only at the nanometer size scale.” said Dr. Stanley Williams, the director of Quantum Science Research (QSR) at Hewlett-Packard Labs in California.
At the nanometer scale, the physical and chemical properties of materials change with their sizes and shapes. For example, if you cut a one-meter long piece of steel in half, it is still a piece of steel. It has the same molecular structure, the same conductivity and magnetic properties. “But if you cut a one-nanometer long piece of steel, everything about it changes,” said Williams.
To cut a one-nanometer long piece of steel needs a scanning electron microscope that enables us to see the atoms that make up that piece of steel. At a recent Nanotechnology Forum in Taipei, Williams showed the picture of a piece of wire made at the Hewlett Packard lab and captured with such a microscope. It measured 3 nanometers wide, meaning that you could see the atoms that made up the wire. The atoms appeared as granular bumps on the surface of the wire. He pointed to a larger bump on the surface and said that they were a clump of atoms that formed on the surface, a mistake in the process of making the wire.
“It’s a small number of extra atoms that just decided to form a little clump and shows you that at the atomic scale, you simply cannot build anything perfectly,” he said. “Below that clump the wire is ten atoms wide, while above it, it is just nine atoms wide.”
Working at the nano-scale means having to deal with the law of small numbers—that there will be fluctuations in the properties of whatever it is nanotechnologists work with. In working with electronic circuits, this means the inability to build anything that works perfectly. “The problem we face is how to build a machine that works exactly how you want it to even though the machine is broken on the day you make it.”
The answer to this question could lie in the foreseen increase in demand for nanodevices such as scanning electron microscopes needed to look at nano surfaces and to work on the nano scale. The scanning tunneling microscope (not to be confused with scanning electron microscopes), or STM, is another nanodevice. It was invented in 1981 by Gerd Binnig and Heinrich Rohrer of IBM’s Zurich Lab. The STM for which the two inventors won a Nobel prize in physics in 1986, allows scientists to visualize regions of high electron density and hence infer the position of individual atoms. The STM can also be used to alter a nanomaterial under observation by manipulating its individual atoms, triggering chemical reactions, and creating ions by removing individual electrons from atoms and then reverting them to atoms by replacing the electrons.
Nanodevices a growing market
In March 2004, R&D magazine cited a survey of the global nanotechnology market. It showed that the market size for nanomaterials was roughly US$7 billion in 2003 and that is was projected to grow to over US$20 billion by 2008. The market for nanodevices was almost non-existent. “There is practically nothing that you could buy today,” said Williams. “But the market will grow from nothing to over US$5 billion dollars per year by 2008.”
The next couple of years the market for nano-enabled circuits and devices will go from practically nothing to many billions of dollars within ten years. The market transformation will likely be felt in the area of computing. “We may be happy with our computer today, but they’re actually just toys,” Williams said. Even the best computers by any definition of efficiency, is outrageously low. They only create wasted heat and can’t perform complex calculations. “The problem is not the transistors; the problem is the wires — charging up all the wiring takes up a lot of energy.”
Since the first commercial transistor radio went on sale in November 1954, the transistor has become the only semiconductor device used for sound amplification, power switching, voltage stabilization, signal modulation and many other functions. It acts as a variable valve which, based on its input voltage, controls the current it draws from a power source. Transistors are made either as separate components or as part of integrated circuits burned on the IC chips that run desktop and notebook computers.
But who needs transistors?
Early last year HP announced that its researchers at QSR had invented a technology that could replace the transistor — the fundamental building block of computers for the last half century — leading to a new way to make computers in the future. Their invention, published in the Journal of Applied Physics, was a “crossbar latch”, two sets of parallel nanowires that connect two plates of integrated circuits. Those nanowires, like transistors, act as switches or valves for the electronic signals that travel within the IC chips that make a computer work.
“We re-invented the computer at the molecular scale,” said Williams. “The technology could result in computers that are thousands of times more powerful than those that exist today.”
Phil Kuekes, a senior computer architect at QSR said that transistors will continue to be used for years to come with conventional integrated circuits. “But this could someday replace transistors in computers, just as transistors replaced vacuum tubes and vacuum tubes replaced electromagnetic relays before them.”
“There is currently a tremendous business incentive to invent new electronic devices and circuits that will have dimensions of the order of nanometers,” said Williams. “New fabrication techniques will be needed that could produce and connect these devices in vast quantities at low cost.”
Leo R. Maliksi is MercatorNet’s correspondent in Taiwan.