Manipulating matter microscopically
04/01/2002
The demand for increasingly smaller and faster semiconductor circuitry has fueled the nanotechnology fires
Mark A. DeSorbo
It can be applied to virtually any kind of process, from micro-machines to wafers to pharmaceuticals to food. It can even make steel stronger.
And the nanotechnology road that lies ahead would indeed have more than just Robert Frost scratching his head, for it is a technological thoroughfare that has some already hitting the trail and others either treading lightly on Mother Earth or stopped dead in their tracks.
Even as less expensive and more powerful devices are being churned out, the demand for increasingly smaller and faster semiconductor circuitry has fueled the nanotechnology fires.
On the life sciences side, nanotechnology is opening up new worlds-insights on microscopic bacteria and contamination that promise to bring forth not only major pharmaceutical and biotechnology breakthroughs, but foster and cultivate new methods of contamination control.
Absorbing the magnitude of nanotechnology is perhaps as complex as the phenomenon itself, but Tim Harper, a physicist formerly with the European Space Agency who is now channeling his expertise into an early-stage nanotechnology fund and conference group in Madrid, recently provided this insight to Red Herring Magazine:
"If you're looking for analogies to put the impact of nanotech into context, I'd say the invention of the internal combustion engine is a good one."
Nanobiotechnology
Whether the benefits are regarded as understatements or exaggerations, nanotechnology has been embraced globally by many industries that depend on contamination control.
The growing list of nanotech backers includes, IBM Corp., the National Cancer Institute, several U.S. automakers, Dow Chemical and a plethora of laboratories and universities in the United States, Europe and Asia.
Nanotechnology is already alive and well in biotechnology, hence the term nano biotechnology.
At Boston University, Tejal Desai, an associate professor of biomedical engineering, works in ISO Class 5 cleanrooms, where she is developing implants for diabetics, many of whom must have regular injections of insulin, a hormone that is produced by islet cells of the pancreas.
Desaiencases the pancreatic cells from mice in a membrane flecked with nanopores that measure just seven nanometers across. The pores are punched in the membrane with the same photolithographic process that is used to etch silicon wafers.
"By using that technique, we can create pores that are between seven and 49 nanometers," she says, adding that Boston University and Ohio State University have collaborated nanobiotechnology research efforts. "We then use the substrate for bio-molecular separation and immune system screening for the implants we're developing."
When glucose from blood flows through nanopores, the enclosed islet cells release insulin. The pores are big enough to allow the passage of glucose and insulin, which are both small in molecular structure. Antibodies, which are significantly larger, are blocked, and thus cannot squeeze through.
"The membranes block the antibodies from attacking the glucose and insulin molecules," Desai adds.
The technique has only been tried on rats, whose immune systems reject pancreatic cells from mice much like the immune systems of human beings would. Diabetic rats implanted with the device, however, have survived for weeks without insulin shots.
Along with therapies for diabetics, Desai says the implants could be used for treating Parkinson's Disease as well as drug delivery systems. With a drug delivery system, however, the blocking power of the membrane would have to be altered to that of a revolving door to allow the necessary drug levels to be maintained.
"Along with drug delivery, we're looking at even broader applications, like cancer therapies," says Desai, who is also an academic partner in I-MEDD Inc. (Columbus, OH), a nanobiotechnology company that her doctoral advisor, Dr. Mauro Ferrari founded. "A few years ago, no one really knew what nanotechnology was. Now many people are developing new technologies and new materials, and the question now is where it will be used."
Physics detour
There are hurdles to overcome, however, says James D. Miendl, a professor of electrical and computer engineering and director of the Microelectronics Research Center at the Georgia Institute of Technology (Atlanta).
"The laws of physics reveal the potential for 20 more years of exponential progress ahead of us," he says of circuitry miniaturization. "If the engineers are clever enough-which historically they have been-they will be able to find ways to produce nanoelectronic structures that physics says are feasible and reasonable."
It would seem that IBM is already stretching the parameters of physics at the T.J. Watson Research Center (Yorktown Heights, NY), where the Nanoscale Science and Technology Group is experimenting with nanotubes, nanolithography and silicon nanoelectronics.
At 10,000 times smaller than a human hair, the hollow carbon nanotubes are manipulated with an atomic force microscope that can change the shape, position and orientation of the carbon-atom structure-a necessary process in order to make devices out of nanotubes, according to group findings found at www.research.ibm.com/nanoscience.
IBM also reports that it can simulate the mechanical behavior of nanotubes by calculating the forces acting between nano tubes and other objects, such as the substrate. As a result, the group has successfully used semiconducting single- and multi-walled nano tubes as channels of field-effect transistors.
The Nanoscale Science and Technology Group has also employed two methods of nanometer-scale local oxidation for semiconductors and thin metal films to make electronic devices.
Calls placed to IBM's Nanoscale Science and Technology Group by CleanRooms were not returned.
Electronic devices using nanotechnology are intended to propel such applications as electromagnetic shielding and flat-panel displays for televisions, computers and other high-tech devices made in cleanrooms, says Ray McLaughlin, chief financial officer of start-up Carbon Nanotechnologies Inc. (CNI; Houston, TX), a maker of single-wall carbon nanotubes.
McLaughlin says the carbon structures have extraordinary properties, including electrical conductivity comparable to copper or silicon, heat conductivity and a molecular-level strength 100 times that of steel.
Since opening its doors in early 2000, CNI has already teamed with Sumitomo Corp. (Tokyo)-an integrated company with ties to aerospace, automotive, microelectronics, telecommunications and foodstuffs industries-to market products using CNI's single-wall nanotubes.
CNI also has partnerships with Duke University (Durham, NC) and Rice University (Houston), where one of the nanotube discoverers, Nobel laureate Dr. Richard E. Smalley, teaches.
"We have agreements with universities and companies to conduct research and further the development of single-wall nanotubes," McLaughlin says.
Nanotechnology has also caught the eyes of some big investors. In mid-February, the banking unit of heavyweight J.P. Morgan Chase & Co., announced it has hired Alan Marty, a former nanotech executive at Hewlett-Packard and Agilent Technologies, to spearhead nano-investing at J.P. Morgan Partners, its private equity arm with $30 billion under management.
He told Reuters that nanotechnology, will "significantly revolutionize" the fields of semiconductors, life sciences, optical networking and others. And like many start-ups in any new field, "there are sure to be a number of companies that will be unsuccessful," he adds.
Nabbing nanoparticles?
So are today's cleanrooms up for the nano technology's challenges?
Yes and no, says Richard A. Matthews, chairman of the ISO Technical Committee 209, which is wrapping up the latest chapter in global cleanroom standards, ISO 14644-8: Molecular Contamination.
"It's going to be a big issue for biotechnology. You're going to see more concern for the removal of gases in the cleanroom, whether they come from outside air, inside the clean space and to some extent, evaporation of liquids," says Matthews, technical director for Filtration Technology Inc. (Greensboro, NC). "It can even be an issue of what people eat. All of these things need to be taken into account."
ISO 14644-8, which is expected to go through the first round of international voting this summer, will address such nano technology challenges as airborne molecular contamination and outgassing by providing "a system for identifying and quantifying contamination."
Containment of contamination will now become more of an issue, too, as a result of nanotechnology, Matthews adds, and that brings end-users into the realm of 14644-7: Separative Devices, isolators and minienvironments, which is up for final vote in June and is expected to be published later this year.
"From an ISO standpoint, we are addressing the issue of nanotechnology with the two standards, and the practical applications for this will be industry and end-user specific," Matthews adds. "Still, some people may not be aware that they may have a potential problem upon them."
null