Scientists at UC San Diego have developed a new kind of LED, and it requires no electricity—instead, it runs on living organisms. A few years back, the researchers were able to engineer one fluorescent bacterium to glow according to a biological clock; in 2010, they got a whole colony to blink at the same time. Now, they've got multiple colonies blinking together, creating a living LED, the Los Angeles Times reports.
The scientists' larger LED screen is only the size of a paper clip, while the smaller is a tenth of that size. But the researchers say they'll be able to make much bigger screens in the future. So what's the point of all this? One application involves detecting arsenic. The team has already developed bacteria that will blink faster when the substance is nearby. "So if you are in Bangladesh and you want to know if there is arsenic in your water, you could use a sensor made out of these chips," says the lead researcher.