O Mundo do Biomédico

Baby-diaper chemistry offers scientists a better view of our brains’ wiring Blowing up a photo can show its details better. In the same way, enlarging a sample of brain tissue can help reveal the bigger picture of how cells in our brains are wired. A chemical similar to one found in baby diapers now gives scientists a new way to do just that.   For many years, disposable baby diapers have contained crystals nestled in their soft lining. Those crystals are a type of “super slurper” chemical known as sodium polyacrylate. It’s a polymer, or molecule made from long chains (hence the poly in its name). Decades ago, chemists learned that when these super-absorbers make contact with water, they suck up the liquid. Suddenly, what had been a powder made from crystals becomes a big gob of moist gel.   Over the years, chemists have turned super slurpers loose to tackle a host of problems beyond leaky diapers. For example, they can help pick up hazardous chemicals...

The bonus: It works for its owner and no one else     Rob Felt, Georgia Institute of Technology   A new keyboard can tell if you’re its owner. It locks out anyone else, even if that person knows your password. What’s more, this device needs no batteries. It harvests all the energy it needs from the action of your typing.   All in all, “This will hugely improve the security of a computer,” predicts Zhong Lin Wang. He’s a materials scientist at the Georgia Institute of Technology in Atlanta and a co-designer of the new keyboard.   “Our fingertips have electrostatic charges,” explains Wang. That means there’s an imbalance of electrons. Your fingertips generally have a slight positive charge. So they have somewhat fewer electrons than the area around them. And that principle makes it possible for typing to induce an electric current in the keyboard, Wang points out. Just as the closely spaced bumps on a lotus leaf (shown here) repel water,...