"In 2006, Michelle Khine arrived at the University of California­'s brand-new Merced campus eager to establish her first lab. She was experimenting with tiny liquid-filled channels in hopes of devising chip-based diagnostic tests, a discipline called microfluidics. The trouble was, the specialized equipment that she previously used to make microfluidic chips cost more than $100,000--money that wasn't immediately available. "I'm a very impatient person," says Khine, now an assistant professor at the University of California, Irvine. "I wanted to figure out how I could set things up really quickly." Racking her brain for a quick-and-dirty way to make microfluidic devices, Khine remembered her favorite childhood toy: Shrinky Dinks, large sheets of thin plastic that can be colored with paint or ink and then shrunk in a hot oven. "I thought if I could print out the [designs] at a certain resolution and then make them shrink, I could make channels the right size for micro­fluidics," she says. To test her idea, she whipped up a channel design in AutoCAD, printed it out on Shrinky Dink material using a laser printer, and stuck the result in a toaster oven. As the plastic shrank, the ink particles on its surface clumped together, forming tiny ridges. That was exactly the effect Khine wanted. When she poured a flexible polymer known as PDMS onto the surface of the cooled Shrinky Dink, the ink ridges created tiny channels in the surface of the polymer as it hardened. She pulled the PDMS away from the Shrinky Dink mold, and voilà: a finished microfluidic device that cost less than a fast-food meal. Khine began using the chips in her experiments, but she didn't view her toaster-oven hack as a breakthrough right away. "I thought it would be something to hold me over until we got the proper equipment in place," she says. But when she published a short paper about her technique, she was floored by the response she got from scientists all over the world. "I had no idea people were going to be so interested," Khine says." - April Buchheit from Bookmarklet

This is pretty cool... making PDMS microfluidic chips is like making jello mold devices. You can make your jello mold out of just about anything, just usually people use high grade silicon, because people already understand really well how to etch it precisely. - Clare Dibble

Cool. I didn't know those were still around. - Gabe

I loved shrinky dinks!! :D - Susan Beebe