In the mobile age, we're largely unfettered by wires, thanks in no small part to Wi-Fi, cellular networking, and the rise of laptops, smartphones, and tablets. But one thin tether keeps us perennially bound: power. Though battery technologies have improved, we still need to charge our devices regularly. So-called "wireless power"—charging or power transmitted to a device without the need to plug that device in—has long been (supposedly) just shy of mainstream adoption.
How thin can an electrical generator possibly be? Thanks to a study published yesterday in Nature, the answer is about as thin as possible. Using molybdenum disulfide, researchers from the Georgia Institute of Technology and Columbia Engineering proved that a layer just an atom thick can generate an electric charge.
Virtually all homes point their solar panels south, where they can best capture rays from the sun when it rises in the southeast and sets in the southwest. That way, residents collect the most power possible throughout the day, which they can use in their own homes or sell to the grid (if they have any power leftover). But critics say the panels would actually do more good facing west, where they could capture sunlight during the midday and afternoon when energy is most needed.
Cryan's research, published today in Proceedings of the National Academy of Sciences, found that certain species of tree-roosting bats are more likely to be killed by wind turbines when the blades are moving at low speeds. By tracking the bats with thermal surveillance cameras, near-infrared video, acoustic detectors, and radar, the researchers discovered that bats tend to approach turbines from downwind, particularly when the turbines spin slowly relative to the wind speeds around them. This led researchers to theorize that the wind currents around slow moving turbines may resemble those created by trees, where the bats gather to roost and hunt insects.