Shrinky dink-idics

Khine displays some shrinky dink molds that will make stem discs.
© Dave lauridsen photography

The first year of a faculty position is tough anywhere. But picture starting at a university that didn’t exist the year before, where the equipment you need to conduct your research is nonexistent, and you get an idea of what bioengineer Michelle Khine experienced in her first year at the University of California, Merced (UCM) in 2006.

She wanted to jump into designing and making her own microfluidics chips, which have become the tiny workhorses of biology labs all over the world, to study how the chemokine interleukin-8 (IL-8) helps immune cells find and destroy pathogens. But UCM lacked the clean rooms and sophisticated fabrication equipment that engineers typically use to make microfluidics chips out of silica. In fact, Khine started her tenure working out of a defunct air force base in the...

While brainstorming ways to make microfluidic chips easily, the 33-year-old Khine harkened back to her youth, when she would play with toys called Shrinky Dinks—sheets of polystyrene plastic that children could cut into shapes, color, then shrink to about a third of their size by baking them in the oven.

Inspiration struck. She drove to a craft store, where she found that her childhood hobby was still for sale. At home, she designed a simple pattern on her computer and ran a plastic Shrinky Dink sheet through her laser printer, marking it with a pattern of the channels and wells she wanted on her microfluidic chip. She popped the plastic into the toaster oven in her kitchen.

It worked. The laser printer deposited ink in miniscule lines and dots in the plastic, which shrunk to about the size of a postage stamp in the oven and could be used as a mold to make polymer chips. The next step: Tell her colleagues about her idea. “I didn’t know if this was crazy, if it would be well received, or if people were just going to laugh at me,” Khine says.

Khine, a faculty member at the fledgling UCM, discusses her work

“All of the sudden, out of the blue, she comes in and says, ‘I have a great idea,’” remembers Anthony Grimes, a UCM senior who was working in Khine’s lab. Her lab set to work refining the fabrication methods to improve the Shrinky Dink chips—optimizing the shrinking of the plastic, jiggering the printer and oven settings, etc.—and about 4 months after Khine pulled her first prototype out of that toaster oven, she published a paper on the new approach in Lab on a Chip, a publication of the Royal Society of Chemistry and the microfluidics community’s most prestigious journal. (LOAC, 8:170–72, 2008.)

Her Shrinky Dink chips could be designed, printed, and made in minutes for mere pennies with the use of a laser printer and a toaster oven. Moreover, the plastic molds could be used more than 10 times to make chips for testing the behavior of various fluids.

The community went bananas over the paper. “The response was just overwhelming,” Khine remembers. “I was getting phone calls and emails from around the world.”

The editor of Lab on a Chip contacted Khine to tell her that her paper was downloaded 18,500 times in December 2008, 5000 more than any other Royal Society of Chemistry papers published that month.

At her new company, aptly named Shrink Nanotechnologies, Khine has successfully used her shrinking concept to create nanoscale features on diagnostic chips that are smaller than 50 nanometers. She’s also helped to develop StemDiscs, which are nano-scale cell wells fashioned similarly to Shrinky Dink chips that can help stem cells grow and develop more tractably. Kenta Nakamura, a medical student at the University of California, San Francisco, is using StemDiscs to grow cardiomyocytes from embryonic and induced pluripotent stem cells. Khine’s StemDiscs allow Nakamura to encourage the development of more consistent embryoid bodies—balls of stem cells whose size and quality directs differentiation into adult cells. “It eliminates one of the huge variables in the process,” he says. “Technologies like Michelle’s StemDiscs may be one of the key technologies that allows us to control the whole process.”

StemDiscs in action aggregating mouse embryonic stem cells

Word and practice of Khine’s methodology spread so far that one day she received a call from the president of K & B Innovations, the company that makes Shrinky Dinks. “She was wondering what was going on,” Khine recalls. “All these scientists were buying Shrinky Dinks. Labs around the world were buying them in bulk.”

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