As Scientific American contributor Rachel Nuwer explains in our December issue, 40 percent of 40-year-olds in the U.S. wear reading glasses. It’s unclear what percentage of that population would be interested in a smartphone or tablet screen that corrects for the flaws in their vision but we predict that the number is high. As it turns out, Gordon Wetzstein of Stanford University and colleagues have developed just such a screen. In this video they explain how it works. See Nuwer’s piece in this year’s World Changing Ideas package for more.

TIGHT SQUEEZE: Massachusetts Institute of Technology chemical engineer Armon Sharei and colleagues have developed a method of squeezing cells in order to temporarily break the cell membrane so as to insert material and alter cell behavior. As a cell moves through a narrowing channel—one of several thousand on a microchip—the action compresses the cell and tiny holes form in the membrane. The device can process a half million cells per second.

CLEAR VIEW: Weary from countless hours of slicing and imaging mouse brains, biologist Viviana Gradinaru of California Institute of Technology developed a method for turning opaque lab-animal tissues transparent. The technique has already helped Gradinaru and her colleagues map the spread of viruses, and soon it will help in the hunt for cancerous cells.





SPIT-FIRED FUEL: Muhammad Mustafa Hussain, professor of electrical engineering at King Abdullah University of Science and Technology in Saudi Arabia, developed this microbial fuel cell to run on an unusual fuel—saliva. The cell generates a tiny amount of power (a microwatt) but it is enough to do useful work—for example, to run lab-on-a-chip systems capable of diagnosing diseases in the field.