The combination of polyethylene glycol (PEG) and polydimethylsiloxane creates what Ye Jin "Jenna" Eun calls a "sandwich of polymers." But when the University of Wisconsin, Madison, doctoral student added water to her creation, it was clear the union of these polymers didn't emulate peanut butter and jelly's happy marriage. PEG wants to expand when it encounters water, but the stiffer polyethylene copolymer won't permit it. So PEG stretches vertically instead, creating the hills and valleys seen here. The contortions make the polymer combo unusable for the original purpose: mounting cell samples. But Eun, who works under the direction of biochemist Douglas Weibel, says the result of the failed experiment was so beautiful, she photographed the image.
Ye Jin Eun and Douglas B. Weibel, University of Wisconsin - Madison