Entry 1
I am working this summer as an intern at NASA's Goddard Space Flight Center as part of a program that integrates students and faculty from universities around the country with NASA employees for summer research work. My project specifically is aimed at developing a nanoscale strain-based magnetometer for planetary and magnetospheric science. Carbon nanotubes are one of the newest most exciting areas within the growing field of nanotechnology because of their unique physical and electrical properties. Some time ago it was discovered that the electrical conductance of individual carbon nanotubes changes significantly when they are bent or stretched. My job for the summer is to try to find a way to embed an array of nanotubes in a flexible material that could be used to extend those findings to a more macroscopic (although still very small...) scale. Once we can find the relationship between the strain on a system of nanotubes and their change in resistance, we can use them as a sensor to detect very small forces, such as those created by magnetic fields in space.
Entry 2
I learned how to use a new machine today-the Scanning Electron Microscope, or SEM. Since you can only see things that are bigger than light waves with a regular optical microscope, we have to use this special type of microscope to look at these tiny carbon nanotubes that we have been growing. If we were to line up ten million carbon nanotubes side by side, it would still only be one centimeter wide! So the SEM uses electrons to create images rather than light waves. An electron gun fires a stream of electrons down at a sample, and if they hit an electrically conducting surface they don't bounce back, so you get a nice image of your sample based on the conductivity of the different parts. Looking at things that are that small is awesome. A little speck of dust on my sample looked like a giant grasshopper! And sure enough, there were the nanotubes. They stretched all across my sample like a tiny network of spider webs. Now that I know they are there, my next goal is to lay down several layers of gold on top of the tubes to make electrical contact and then measure the resistance of the nanotubes. What an amazing tool!
- Jon Brame
Jon Brame interned at NASA's Goddard Space Flight Center in Maryland this summer. He is majoring in Physics at BYU.