Small Worlds

A new electron microscope gives students a window to the unseen.
Maybe it wouldn’t fit in the sleigh. Maybe chimney soot would have clogged its carefully calibrated innards. Whatever his reasons, Kris Kringle checked Bainbridge High School off his list early this year, delivering a gently used scanning electron microscope in time for a few trial runs before the holiday break.

A new electron microscope gives students a window to the unseen.

Maybe it wouldn’t fit in the sleigh.

Maybe chimney soot would have clogged its carefully calibrated innards.

Whatever his reasons, Kris Kringle checked Bainbridge High School off his list early this year, delivering a gently used scanning electron microscope in time for a few trial runs before the holiday break.

“It takes you to a level (of detail) you can’t even imagine existed without it,” BHS biology teacher Bruce Claiborne said of the new instrument.

“We owe the Crawfords tremendous thanks.”

That’s district Superintendent Ken Crawford and his wife Susan, chief elves in an acquisition that makes Bainbridge one of only five public high schools in the country, and the sole high school in the state, to own an SEM.

The windfall came the Crawfords’ way this spring, when the Navy offered the 12-year-old instrument for use as an exhibit at the Naval Undersea Museum in Keyport.

When the museum declined, the Navy decided to sell the machine to an educational institution.

Susan Crawford, director of a science education program based at the Keyport museum, knew of just the place.

To prevent the microscope from being banged up in the surplus depot at Fort Lewis, Susan Crawford negotiated with the base commander to keep the microscope in a controlled environment at Keyport, while her husband prepared to make a case for the instrument to come to Bainbridge.

Enlisting the support of the Bainbridge Island Schools Trust, Crawford made his pitch for the microscope, competing against three other educational institutions.

“We focused on the success of our students – how many of them go on to universities,” Ken Crawford said. “The microscope is a great opportunity to prepare them in technology and science.

“They decided we offered the greatest educational benefit.”

The total bill: $9,000, for an instrument Navy surplus valued at $70,000. In the public resale market, similar models list at twice that price, Crawford said.

Fly-by

One of the first students to be trained on the new equipment, 17-year-old Nissa Kahle, is already putting the machine through its paces.

“I’m glad this came when I was still a junior,” Kahle said. “I’m really looking forward to working with it.”

With Claiborne supervising, Kahle flips a switch, and the SEM hiss-hums to life.

Forget lab-coated chemists peering through tubes at glass slides, trying out lenses like so many Groucho Marx noses – the high school’s new prize bears little resemblance to an optical microscope.

Parked in a classroom the size of a large utility closet in the high school’s science wing, the device looks like a space-age Hoover upright parked next to an early-era PC.

Unlike an optical microscope, which uses lenses to bend light waves to create a magnified image, the SEM bombards the specimen with a stream of electrons.

The barrage knocks loose other electrons that are counted by a detector, and then translated into an image – creating a topographic map of the tiny specimen inside.

The result is an incredible degree of magnification – up to 70,000 times actual size, compared to the 400x of the high school’s best optical scopes – and an image resolution that far surpasses that which visible light can produce.

On this day, the specimen chamber contains a dessicated bit of Aphrocallistes vastus, a cloud sponge, which shows up as a pockmarked green image on the screen.

And then Kahle is flying above the cloud, panning across the image, diving in for a closer look. The image zooms to 40, 200, 600 times the specimen’s size, until the pitted surface of the sponge recedes, becoming a forest of spines.

“They’re spicules,” Claiborne says, flying in for a 670x look at the many-pointed structures. “They’re like rebar in concrete; the flesh of the sponge molds around them.

“I’ve seen it in books, but I’ve never seen it like this.”

Manning the scope is like being in an IMAX movie or a jet-fighter simulation – and it is clear that both teachers and students are hooked.

When they aren’t testing gazing at small wonders, they are dreaming up ways to incorporate the SEM into the school district’s new math and science curriculum.

“We hope to develop a long-term research project that students can work on pieces of (each year),” said BHS science teacher Dr. Louise Baxter.

To do that effectively – to view biological specimens, in particular – the microscope needs a few upgrades.

Kahle’s fly-by with the sponge reveals why: after only a few minutes of scanning, the image begins to shimmer, indicating that the specimen is beginning to deteriorate under the electron stream.

The solution: a critical point dryer, to completely dessicate the specimen, and a sputter coater, to deposit a layer of metal over the surface, protecting it from decay.

They also hope to replace the microscope’s primitive Polaroid with a digital camera – a wish list that totals about $15,000.

“We’re hoping that, between their building budget and the district budget, that we can find the money in time to have (the improvements) in place by the beginning of the next (school) year,” Crawford said.

For now, staff and students are more than getting by. As for other members of the community, the arrival of the SEM has met more than educational objectives.

As one school board member said, “Mercer Island doesn’t have one.”