Outside Washington, D.C., just a stone’s throw up the road in Gaithersburg, Md., lies the sprawling 580-acre headquarters of the National Institute of Standards and Technology (NIST), an unheralded government agency that has played a part in some of the biggest advances in science, manufacturing and communications in the last century.
To be precise, the front gate of the institute’s wooded, rural campus is exactly 20.664 miles from the center of the U.S. Capitol Building. It’s worth mentioning, because NIST is in the business of precision: everything the institute does revolves around standards, measurements and comparisons, all reliant on a meticulous attention to detail. Since it was established in 1901, the agency has worked to promote U.S. innovation and industry by developing tools that help speed up research, ensure the reliability of manufactured goods, and improve our quality of life.
Everything from the recipe for steel used in automobile production to earthquake safety standards for buildings to the nation’s official atomic clock stemmed from the efforts of NIST researchers.
The institute’s bucolic setting — complete with wildlife like deer and foxes — belies a modern core of state-of-the-art facilities like the Center for Nanoscale Science and Technology. This massive concrete, steel and glass building houses laboratories isolated as much as 40 feet underground, tightly temperature- and humitity-controlled so as not to perturb the exquisitely sensitive experiments conducted there.
It’s in this pantheon of precision that researchers Gordon Shaw and Jon Pratt are working to develop new standards for measuring extremely tiny forces, all the way down at the molecular level. The centerpiece of their Small Force Metrology Lab is the atomic force microscope, a phenomenally sensitive instrument that can create an ultra-high resolution image by dragging a silicon strip tipped with a diamond point (much like a phonograph needle) back and forth over a surface, and measuring the force exerted on the silicon strip as it bends and flexes with the contours of the surface.
What Shaw and Pratt are looking for is a new way for scientists using atomic force microscopes around the world to cheaply and efficiently calibrate their machines. Their current research is exploring the hypothesis that tiny snippets of DNA could be used as a “standard reference material” for just such a purpose.
Shaw, a stocky, enthusiastic man with a ready smile and long brown hair pulled back into a ponytail, explained the concept in the cramped atomic force microscope control room. DNA, he said, has some basic characteristics that make it appealing as a reference material: it’s cheap to produce, it can be replicated identically every time, and it appears to break when stretched with a predictable amount of force.
“Anyone can really make this DNA molecule,” Shaw said. “Our goal is to come up with a recipe that people can repeat anywhere in the world and get the same force.”
To test this idea, Shaw places under the microscope DNA that has been specially treated so one end of each strand sticks to the surface being scanned, while the other is attracted to the tip of the silicon probe. Then, he goes fishing. When the probe has snagged the loose end of a DNA molecule, the researchers gradually pull on it until it comes apart, then record the force at which it broke.
With any luck, their research will be a success, and before long yet another NIST recipe for precision will be circulating the globe, helping spur scientists and entrepreneurs to break new ground and push the boundaries of technology ever further forward.
Excellent description of the NIST campus and Shaw's research on developing DNA as a reference standard!
ReplyDelete