By Thomas Hansz
The technological advances of the last half of the 20th century brought the prefix micro into everyday use. Everything from microprocessors to micro-mini skirts affected the way we worked and relaxed. Now, a new prefix—nano—is starting to creep into our national vernacular.
To put nano into perspective: A micron (µm) is one one-thousandth of a millimeter while a nanometer is one one-thousandth of a micron. When reference to nanotechnology appears, think of a manufacturing process that enables us to snap together the fundamental building blocks of nature easily, inexpensively and in most of the ways permitted by the laws of physics.
This sub-micron approach to research and production will be taken in everything from medical sciences to electronics to material sciences, and will potentially touch every aspect of our daily lives—from the medicines we take, to the cell phones we use, to the clothes we wear.
The Federal government has made a significant commitment to the development of nanotechnology and its impact upon the national economy by sponsoring the National Nanotechnology Initiative (NNI). During the course of 2002, the Fed spent close to $700 million on nanotechnology R & D; and according to the NNI, this amount will undoubtedly increase this year and next.
Last month, the NNI held a conference in Washington, D.C. to present advances in nanotechnology, and to provide assistance and direction to interested businesses, universities and investors. Government agencies that participated in this three-day event included the Department of Agriculture, Department of Defense (DOD), Department of Energy, Environmental Protection Agency, NASA, National Institute of Health and the National Institute of Standards and Technology, as well as agencies within each department.
Nanoscience vs. nanotechnology
Nanoscience has actually been around for a long time. The microelectronics industry has been working at the sub-micron level for more than the past decade; however, new advances in the material sciences have been accomplished through synthetic capabilities of controlling size, shape, crystallinity and purity of high quality materials.
Nanotechnology is not just micro devices getting smaller. Nanomaterials and molecules behave differently in their quantum states, with nanomaterials displaying or using new phenomena—especially with self-assembly.
New methods will be required to quantitatively measure and characterize structural and conductive properties of electrically active molecules on a large scale. The challenge before the United States is the development of the processes for the commercial manufacturing of nanotechnology advances. Much of this development will depend upon the ability to measure and characterize assembly of components into complex structures, along with the chemicals and materials used in the manufacturing processes.
Larry Bock, president and CEO of Nanosys, Inc., explained the difference between nanoscience and nanotechnology: “Nanoscience is the fabrication, characterization, manipulation, modeling and precision placement of nanometer-sized materials. Nano becomes a technology when it is combined with other sciences or technology.”
According to Bock, this is not a new technology, rather it is a type of material science that can be applied to other sciences using new parameters.
Sandip Tiwari, Ph.D., professor of electrical engineering at Cornell University and director of the National Nanofabrication User Network, provided one of the many unique examples of how we can expand our horizons at the nano level. One of the keys, says Tiwari, is understanding the toes of the very ordinary Gecko.
These small lizards have the remarkable ability to cling to any vertical surface, no matter how smooth. Upon close examination, each foot of the Gecko has nearly 500,000 structures called setae that are approximately 20 µm in length. Each seta terminates in bundles containing hundreds of nanoscale spatulate structures.
“The adhesive force of each seta is due to the molecular level van der Waals interactions [intermolecular forces of attraction] between the spatulate structures and the surface,” says Tiwari. “Synthetic nanoscale setae are being developed, which will radically change the way materials will adhere together in the future.”
The super battle suit
The Institute for Soldier Nanotechnologies at MIT is a partnership involving the DOD, major corporations and MIT to reduce weight and increase protection for soldiers in combat. A major concern of weight reduction is alleviating the weight of batteries for portable electronic equipment. Everything from two-way radios to night vision glasses requires batteries, of which there are currently more than 41 different types used for field operations. Smaller, more powerful, interchangeable batteries are being developed with the help of nanotechnology innovations.
Another typical innovation is the Dynamic Battle Suit, which is a multi-layered fabric that protects the soldier from chemical-biological warfare agents as well as ballistic penetration and blast waves. At the same time, the total battle suit provides communications, data collection and transmission, and physiological monitoring of the soldier with less weight than current uniforms.
Sure, this sounds like science fiction, but through the development of hybrid material combinations unavailable in nature, the dynamic battle suit is soon to be a reality.
Certain bacteria death
Jeffrey A. Schloss, Ph.D., director of technology development at the National Human Genome Research Institute (NHGRI), a component of NIH, presented an example of advances in the life sciences. The manner in which bacterial infections are eliminated and therapeutics are delivered will dramatically change, he says. Along with the Scripps Research Institute, the NHGRI is developing a new class of antibacterial peptides, or low-weight polymers of amino acids.
Nanotubes are then formed by self-assembly of cyclic peptides composed of alternating D- and L- amino acids. With appropriate design, the nanotubes insert themselves into bacterial cell membranes; pores are then created, resulting in bacterial cell death.
Interestingly enough, the nanotubes will not insert themselves into mammalian cell membranes, leaving the body systems unaffected.
Some compounds that are insoluble or are toxic to human body systems are being reexamined for therapeutic delivery at the nanoscale. These compounds can be delivered directly to their site of action, resulting in lower body concentrations and greater effectiveness.
How will the increase of nanotechnology innovations affect the cleanroom industry? Obviously, there will be a need for more contamination-controlled research and production environments. But will they be similar to current cleanrooms, or will they be hybrid types suited for not-yet-developed applications? We'll soon find out these critical answers.
Thomas E. Hansz, AIA, is founder of Facility Planning & Resources, Inc., the director of Advanced Technology Projects for Flad & Associates, and a member of the CleanRooms Editorial Advisory Board. For a list of Nanotechnology Centers and Institutions in the National Nanofabrication User Network, contact Tom at: [email protected]