Who's who at NASA: Dr. Meyya Meyyappan, director, Center for Nanotechnology, Ames Research Center

Dr. Meyya Meyyappan is the Director and Senior Scientist at the Center for Nanotechnology at NASA's Ames Research Center in Moffett Field, CA. His team is presently researching and developing carbon nanotubes.

NASA Tech Briefs: How long has Ames' Center for Nanotechnology been operating?

Dr. Meyya Meyyappan: We started as a small group in 1996, and since then, the center has grown to have 50 full-time scientists. Our nano center is the largest in-house nanotechnology effort within the government, and it is also one of the largest in the world.

NTB: What nanotechnology projects are you currently working on?

Dr. Meyyappan: First, we are using nanotechnology in the area of electronics and computing, or nanoelectronics and computing. We are also developing nanotechnology-based sensors and detectors, and we are utilizing nanotechnology in gene sequencing. Our project focus is primarily material-driven and we are looking at a variety of nanoscale materials. The first and the major focus is on carbon nanotubes.

The next class of materials that we are working with is inorganic nanowires, like zinc oxide and gallium nitride, for the manufacture of sensors and detectors. The third class of materials is protein-based nanotubes, which are biological. We synthesize them in large quantities and purify them. We are using them for applications like templates for lithography.

NTB: What are carbon nanotubes?

Dr. Meyyappan: Carbon nanotubes look like nanoscale cylinders, about 1 nm or so in diameter and a few microns long. Imagine rolling up a sheet of graphite into a tube; that is what we are talking about. There are a few procedures in the lab we are using to grow these structures. One method is called Chemical Vapor Deposition (CVD), which uses some hydrocarbon gases such as methane with a catalyst material like iron. In the second method, called plasma enhanced CVD, we use low-temperature plasmas to grow nanotubes.

NTB: Why are nanotubes so versatile and functional to many industries?

Dr. Meyyappan: Carbon nanotubes have extraordinary mechanical properties. For example, compared to steel, nanotubes have a strength-to-weight ratio of 500. At the same time, nanotubes can be used to make a computer chip, because in addition to these wonderful mechanical properties, they also have very exciting electrical properties.

Historically, the materials we used for computer chip applications were impractical for construction of an aircraft. The same with aluminum or stainless steel - these metals could be used to manufacture an automobile, but they could never be used to make a computer chip. Carbon nanotubes can be used for both fine applications like computer chips and sensors, and for massive applications in the aerospace and automotive industries.

NTB: Is NASA currently using carbon nanotubes?

Dr. Meyyappan: There are some applications that are already beginning to emerge. We have used carbon nanotubes as a tip in an atomic force microscope. We are also trying to create biosensors using carbon nanotubes because biosensors are important to NASA in terms of astrobiology applications. We are also involved in a program with the National Cancer Institute to develop carbon nanotube-based biosensors for cancer diagnostics. We are pretty much in the research stage, but I believe that in a few years' time, we will slowly start migrating up the ladder towards deploying the actual applications.

A full transcript of this interview appears on-line at www.nasatech.com/whoswho. Dr. Meyyappan can be reached at meyya@orbit. arc. nasa.gov.