The task of materials scientists is to create stronger, lighter, and better materials, materials with new and useful properties. One very helpful tool for understanding materials would be a microscope powerful enough to "see" individual atoms.
Now a new electron microscope at Berkeley Labs can produce images of individual atoms. The microscope, which is called TEAM 0.5, produces images with half-angstrom resolution. This is less than the diameter of a single hydrogen atom.
TEAM stands for Transmission Electron Aberration-corrected Microscope. Electron microscopes use a beam of electrons instead of visable light. The quality of what is seen through a microscope is dependent upon correcting lens aberration and upon the alignment and quality of all the components.
The information limit of a microscope results from mechanical and electromagnetic instabilities. Recent technological advances make it possible to improve mechanical stability by increasing the column’s mechanical stiffness, and to reduce electromagnetic instabilities by stabilizing the fields to an accuracy of about 100 parts per billion. These measures will extend the information limit beyond 0.05 nanometer. National Center for Electron Microscopy at Lawrence Berkeley National Laboratory
Although bright light makes for better viewing, the equivalent high energy electron beams often destroy what is being looked at. The TEAM 0.5 microscope can now provide good viewing of sensitive targets with electron beam intensities as low as 80kV. Low energy electron beams will allow visualizing organic samples.
The TEAM 0.5 microscope was used to look at a sheet of graphene. Individual atoms of carbon can be seen in the honeycomb shaped image. (click this link for the "Closest look ever at graphene")
The position of individual atoms in a structure can be determined by taking images at different angles, from which the computer reconstructs a 3-D tomograph of the sample, as in a CAT scan. To make this possible an innovative system capable of tilting and rotating the sample, and moving it up, down, or sideways under the electron beam, is also being developed at NCEM.
The current version of microscope, the TEAM 0.5, will be available to users next month. The next version, the TEAM I, will have even greater capablities.
Manipulating the sample by such methods as minute piezoelectric "crawlers" that change shape when electricity is applied, the new stage will be able to control and reproduce the sample's position and attitude with an accuracy of less than a billionth of a meter.
Click this link to see the timetable of TEAM development
I am on vacation and actually have some time to explore the lighter side of scientific thought. Digging through a used bookstore I found this great little poem from Emily Dickinson and thought it bared repeating:
"Faith" is a fine invention
When the Gentlemen can see--
But Microscopes are prudent
In an Emergency.
I wonder what she would say about nanotech today?
Physicist Kenneth Libbrecht used a high-resolution microscope to take pictures of snowflakes. These images were put on to four new 39-cent commemorative stamps by the United States Postal Service. The images were taken from snowflakes in Michigan, Alaska, and Ontario. To take the picture, Libbrecht used a paintbrush to transfer the snowflake onto a glass slide. He then took the picture using a digital camera through a high-resolution microscope. Libbrecht does most of his work outside to keep the snowflakes from melting. According to Libbrecht, there are 35 different types of snowflake crystals. The stamps feature two specific types, stellar dendrite snowflake crystals and sectored plate snowflake crystals.
Snowflakes are created when a water droplet inside a cloud freezes into an ice particle. The particle spreads out and becomes a six-sided prism as water vapor gathers on its surface. As more vapor accumulates, the prism grows branches and begins to look like a crystal. No two snowflakes are the same because, inside the cloud, the snowflake crystal is pushed around between temperature and humidity changes which affect the shape of the snowflake.