The Secret in the Suburbs

These folks know all about you. They know how much your Fruit-of-the-Looms weigh and how much vitamin C is really in your Centrum. They know the size of your Michelins and how much air they’d better hold to keep you rolling, and they know that a .38 slug will leave a dent the size of an orange in your Kevlar vest. They know whether your dentist’s autoclave reaches the temperature needed to sterilize the drill, and whether her latex gloves will tear as she’s stretching her fingers toward your molars. If it’s your business, it’s their business.

They are the people who labor at the National Institutes of Standards and Technology. Their business is metrology, the science of measurement. According to Gail Porter it’s a business as old as, well, business. And you haven’t heard of it, because NIST, like any enterprise, keeps its valuables under lock and key, deep in unassuming Gaithersburg, Maryland, a dozen miles north of Washington DC.

Porter is NIST’s Public Affairs Director, which means she’s in charge of leading tours through the facility. We are eight adult writing students, tired after a humid summer workday. Porter is an energetic woman, dressed head to toe in business brown. She greets us at dusk, with a van in a parking lot outside the facility. After we pile in, she drives us past the guarded gatehouse and winds through a five hundred acre parkland.

The forests and lawns are home to deer, foxes—and laboratories buried forty feet below ground. “To minimize vibration,” Porter explains. And there are to be no perturbations in our schedule, either. She has arranged for us to tour the museum, visit three labs, and listen to three lectures, all in exactly 90 minutes.

We disembark at an exhibit hall and Porter herds us inside. She strides down the waxed linoleum with elbows pumping, while we struggle to follow. We think we have come to learn about nanotechnology, but we gape at smashed cars and lists of peanut butter ingredients. Porter is careful to point out that NIST developed expressly to serve commerce. It’s because of NIST that buying peanut butter is something shoppers can do with confidence. A jar of Skippy’s weighs a pound and holds a pint of a standardized mixture of peanuts, salt, fat and sweetener that can be called peanut butter. But how do you measure—and sell—something as small as a molecule? That question is what made NIST scientists turn their attention to nanotechnology.

Our next stop is “Building 216.” There, in an underground laboratory, Jon Pratt has assembled an instrument he calls “an electrostatic force balance.” Pratt has close-cropped silver hair, but looks boyish in skinny jeans. Porter reminds him that we have two lectures after his, so he speaks quickly, explaining that mass is not the same as weight, but more fundamental. Weight depends on gravity, but gravity is not constant throughout the universe. For example, we weigh more on earth than we would on the moon, but we still have the same mass. Pratt moves on to his electrostatic force balance—a scale—used to measure the mass of extremely tiny objects, say strands of DNA. Instead of using gravity to measure mass, Pratt’s scale uses the intrinsic electrostatic forces surrounding an object, even one as small as a molecule.

Nested in a ceiling-high cylinder of gleaming brushed steel, Pratt’s instrument is actually a probe shaped like a diving board, with a point one atom in diameter. The object to be “weighed” is moved toward the probe, and as it approaches, the object’s electrostatic field bends the probe up or down. The more massive the object, the bigger the deflection.

But that lecture is over, and we are handed off to Gordon Shaw. Shaw, also in jeans, is younger and stockier than Pratt. With enthusiastic hand motions, he explains that Pratt’s instrument allows him to measure the force required to rupture a strand of DNA (a standardized strand, of course).

Shaw leads us down an endless hall to his temperature-controlled laboratory. We crowd into a room slightly larger than a closet, and Shaw points to a work station. There, on a computer monitor, we see Pratt’s tiny diving board at work, dutifully deflecting before strands of protein. Shaw apologizes for not showing us strands of DNA. Someone tries to deflect the apology by saying that to us, protein or DNA, it’s all the same. Shaw’s voice drops. Not protein, he says, but DNA, will one day be the industry standard for measuring force on the molecular level.


But Porter has come to collect us and take us to our final stop, the laboratory of Samuel Stavis. Three years out of his PhD program, Stavis has neatly-cropped hair and Ivy League confidence. He ushers us into the small floor space separating his sprawling stereoscopic microscope from a counter that holds a dish labeled “Fragile.” His job, says Stavis, is to order a varied mixture of nanoparticles by size. To do this, he builds tiny tapering chutes, then forces nanoparticles into the chute. The nanoparticles travel down the narrowing chute and stop when their diameter equals that of the chute. Large particles stop sooner than small particles. It is a simple idea, and it strikes us as ingenius.
There are still some problems to work out, says Stavis, like how to separate the various particles once they’re stopped. But Stavis has published a paper on the topic, and the biomedical industry is reading it.

Tours are not available for the general public. But Nist does not consider students, industry groups, scouts, consumer groups, non-profits, and so on "the general public". So if you can talk Gail Porter into believing you’re not a member of the general public, a tour is well worth your time.

http://www.nist.gov/public_affairs/