For nanotechnology to become a commercially viable and feasible mass-production technology that can produce useful nanodevices and sensors, a production infrastructure is needed. Unlike the present situation where a few atoms and carbon single-walled nanotubes (SWNTs) are manipulated with atomic-force microscopes (AFMs), we must learn to manipulate millions and billions of atoms and SWNTs at a high rate of speed and reliability.
Fortunately, there some answers. When we examine the potential routes to nano manufacturing, three technical barriers always surface: the need for guided self-assembly and wiring, the need to solve reliability and testing challenges, and the need to come up with high-volume and high-throughput-rate processes. This requires that a completely different set of fundamental research issues be addressed. One viable approach is the use of high-rate and high-volume templates for nano device manufacturing.
Nanotemplates can be grown in a self-ordered manner on strained interfaces. These wires can be electrostatically addressable, where nanotubes are aligned on negatively charged nanowires via non-covalent electrostatic attraction. Then, a new substrate is introduced for stronger interactive attractions, and the nanotube transfer thus is completed (see the figure).
Innovative MEMS devices can also help characterize nanowires, nanotubes, nanorods, and nanofibers. They can be used to conduct accelerated lifetime testing, allowing rapid mechanical, electrical, and thermal cycling of nano devices.
One of the largest challenges is control of nano defects and contamination for effective nanomanufacturing. This means we need to better understand the selective removal of impurities like oxygen and have a greater understanding of chemistry's role. Moreover, we must better comprehend the adhesion of particles and nano elements in a variety of conditions and situations. An important challenge is the ability to clean nano structures without destroying them.
We can elucidate all of these factors thanks to research conducted at our ultra-modern 5500-ft2 clean room at the George J. Kostas Nanomanufacturing Center at Northeastern University. It includes a complete microfabrication facility, with bulk and surface micromachining and e-beam lithography. It also includes a laser surface scanner (200-nm resolution), a laser airborne and liquid counter (200-nm resolution), CNC particle counters (10-nm resolution), Zeta potential measurement down to 1-nm particles, and an AFM, in addition to optical and finite-element scanning-electron microscopy.
This sidebar was excerpted from a presentation made at Sensors Expo 2004 by Ahmed Busnaina, W.L. Smith Professor and director of the Nanomanufacturing Research Institute of the NSF Center for Microcontamination Control at Northeastern University, and coauthored by Joey Mead of the University of Massachusetts Lowell Center and Glen Miller of the University of New Hampshire in Durham.