Nanotechnology is a buzzword from the scientific community and the subject of many publications for over a decade. It has virtually unlimited future potential to produce and improve new and existing products. In January 2000, the U.S. government committed $500 million to the National Nanotechnology Initiative. President Bush's proposed 2003 budget contains $679 million (a 17% increase) for the National Nanotechnology Initiative. Yet, as sometimes occurs, it also has a potential dark side.
To understand the pros and cons of this new technology, let's first discuss what's involved. Then, you can decide if it's a good thing.
Nanotechnology is based on the principle that the properties of manufactured products depend on the arrangement of their atoms. To minimize manufacturing costs, it proposes to use replication of processes wherever possible. For example, rearranging the atoms in sand and adding the appropriate impurities should allow us to make improved integrated circuits, power semiconductors, etc. Rearranging the atoms in coal should produce diamond.
The book, Unbounding the Future: The Nanotechnology Revolution, by Drexler, Peterson, and Pergami (1991) notes that nanotechnology will replace chemistry and mechanical engineering as we know them. It stands to reason that it will impact power electronic engineering and change manufacturing as we know it today.
Physicists are already looking at ways to use nanotechnology for power semiconductors. A recent Applied Physics Letters included a scheme for the fabrication of ultrashort channel MOSFETs. Its abstract explained: “We present a scheme for the fabrication of ultrashort channel length metal-oxide-semiconductor field-effect transistors (MOSFETs) involving nanolithography and molecular-beam epitaxy. The active channel is undoped and defined by a combination of nanometer-scale patterning and anisotropic etching of an n++ layer grown on a silicon on insulator wafer. The method is self-limiting and can produce MOSFET devices with channel lengths of less than 10 nm. Measurements on the first batch of n-MOSFET devices fabricated with this approach show very good output characteristics and good control of short-channel effects.”
Many authors have written about nanotechnology. One of the better articles appeared in the January 2001 issue of IEEE Spectrum. Authored by Ralph C. Merkle of the Zyvex Corp (Richardson, Texas) it was entitled “Nanotechnology: What Will It Mean?” The author starts out by noting “Nanotechnology will make us healthy and wealthy though not necessarily wise. In a few decades, this emerging manufacturing technology will let us inexpensively arrange atoms and molecules in most of the ways permitted by physical laws. It will let us make supercomputers that fit on the head of a pin and fleets of medical nanorobots smaller than a human cell able to eliminate cancer, infections, clogged arteries, and even old age.”
Merkle pointed out that there could be two problems with this technology — deliberate abuse or accidents. The deliberate abuse by small groups or rogue nations could cause harm through the use of materials of mass destruction. Accidents could be due to a self-replicating molecular machine that goes unchecked, eventually causing harm to people or the environment.
Zyvex is investigating a replicating positional assembly system at the micron, submicron, and molecular scale. It's developing simple pick and place robotic arms that can pick up complex planar, micron scale parts made with lithographic techniques and assemble them into simple 3-D robotic arms that can pick up other specially designed parts. According to Merkle, “This replicative technology starts with a single robotic arm on a wafer that then assembles more robotic arms on a facing wafer by picking up parts already laid out in precisely known locations.”
To prevent destructive nanotechnology systems, the nonprofit Foresight Institute (Palo Alto, Calif.) generated a set of draft guidelines for developers and manufacturers. Merkle said the guidelines include statements that “artificial replicators must not be capable of replication in a natural, uncontrolled environment. They must have an absolute dependence on an artificial fuel source or artificial components not found in nature; they must use appropriate error detection codes and encryption to prevent unintended alterations in their blueprints and the like.”
Although nanotechnology products are years away, is this a good thing, or bad? Is it an ethical problem, similar to nuclear energy with its good and bad points? Is it a threat to power electronics engineering and manufacturing as we know it? Is the “march of science” going too far? Send your comments to [email protected].