Nanotechnology: A Multidisciplinary Emerging Technology

Nanotechnology, molecular scale science, has been “emerging” for decades as the technology has advanced.  Scientists from multiple disciplines-engineering, physics, chemistry, biology, etc. have contributed to this growth through combined efforts that transcend boundaries of the individual disciplines. Nanotechnology, a prevalent science fiction concept, is maturing as a multidisciplinary domain that is approaching an attainable reality whose applications will be routine.  For about 70 years, electron microscopes have enabled scientists to observe nanoscale structures - a red blood cell’s diameter is approximately 7 micrometers or 7,000 nanometers; a DNA molecule is about 2.5 nanometers wide. Nanotechnology has produced molecular wires, split gate quantum dots that allow regulation of one electron flow and a variety of other applications.

When we contemplate the construction of machines and devices we do not usually consider a process that can be carried out atom by atom. On the macro level, the components used for product assembly are cut out from larger blocks of a material by a range of sophisticated engineering techniques. However, some components, for example those on a computer chip, are so small, that they could be considered as being built from individual atoms or molecules. The size in which this transition from classical engineering concepts to chemical assembly becomes practically feasible lies between one and a hundred nanometers. Making components in this 1 to 100 nm size regime and assembling them into devices is Nanotechnology.

Brookhaven Lab scientists ScienceDaily (Mar. 13, 2008) have developed a new method for controlling the self-assembly of nanometer and micrometer-sized particles. Based on designed DNA shells that coat a particle's surface, the method can be used to manipulate the structure of numerous materials. Such fine-tuning of materials at the molecular level may lead to numerous applications, including cell-targeted systems for drug-delivery and bio-molecular sensing for environmental monitoring or medical applications. "Our method is unique because we attached two types of DNA to the particles' surfaces," said Brookhaven researcher Dmytro Nykypanchuk. " The first type of DNA forms a double helix, while the second type is non-complementary, neutral DNA, so it provides a repulsive force. The addition of the repulsive force allows for regulating the size of particle clusters and the speed of self-assembly with more precision."  In subsequent experiments, the researchers used DNA to guide the creation of three-dimensional, ordered, crystalline structures of nanoparticles. Engineering such 3-D structures is important for producing materials with unique properties that exist at the nanoscale, such as enhanced magnetism and improved catalytic activity.  This new assembly method relies on the attractive forces between complementary strands of DNA, but the scientists also heated the DNA-linked particles, then cooled them back to room temperature. "This 'thermal processing' allows the nanoparticles to unbind, reshuffle, and find more stable binding arrangements," Gang said. A patent application has been filed for the technology.

A newly defined biochemical pathway in plants Science Daily (Mar. 9, 2008) may provide the scientific tools to design plants that will yield larger quantities of alternative transportation fuels than currently can be produced, according to Purdue University researchers.  Work at the nanoscale level can lead to innovations that allow surgeons to successfully repair a weakened artery, and allow chemists to develop safer, more effective, crop protection treatments or create a pair of pants that change depending on the weather!    Ultimately, nanotechnology is considered an enabling technology that is leading to advanced materials, devices, and applications that improve life, health, safety, and the environment. The pathway moves materials that determine cell shape and size through a system of signaling proteins, said Dan Szymanski, a plant geneticist and cellular biologist. By learning more about the growth and development process, it may be possible to engineer plants with improved properties such as cell walls that are more massive or are more easily fermented in the biofuel process. "We expect that cell wall material will to be a major source of biomass from plants designated for biofuel production," Szymanski said. "We need to learn more about how plant cells control the quality and amount of cell wall material."  He and his research team investigated plant growth and cell wall development from several scientific approaches in determining the cascade of events that leads to changes in the cell wall. They discovered that a protein called "SPIKE1" directs the protein signaling pathway. They report their findings in "Early Edition," the online publication of the journal Proceedings of the National Academy of Sciences. The study also will be published in the journal's March 11 print issue.  The scientists hypothesize that SPIKE1 may both generate and organize protein complex signaling, Szymanski said. They also need to discover what activates SPIKE1. When the researchers understand enough about the processes involved in plant cell growth and development, then they may be able to design plants that are bigger with more cell wall that can be processed into biofuel. "Learning more about SPIKE1 likely will help us gain a better understanding of the mechanics and regulation involved with the pathways that control cell architecture and development in plants, and also may be relevant to animal and human growth and development," Szymanski said.  The scientists hypothesize that SPIKE1 may both generate and organize protein complex signaling, Szymanski said. They also need to discover what activates SPIKE1. When the researchers understand enough about the processes involved in plant cell growth and development, then they may be able to design plants that are bigger with more cell wall that can be processed into biofuel. Nanotechnology will eventually be ubiquitously applied throughout all disciplines, and scientists currently focused in traditional technologies may well consider it to be in a position to successfully shift with the evolving paradigm.