As if bats weren't badass enough, we now know that their wings are loaded with ultra-sensitive sensors that help the bats manoeuvre like airborne ninjas. This could lead to aircraft design that might reduce turbulence, improve flight control, and generally be a lot less clumsy.
Researchers at Johns Hopkins University, Columbia University, and the University of Maryland have shown for the first time just how crucial touch sensors in the night fliers' souped-up webbed appendages are. The paper was published today in the journal Cell Reports.
If a bat flies into a sudden gust, it can agilely switch directions in milliseconds. The secret to its whip-fast wind acrobatics is a keen sense of touch: Bat wings are blanketed with tiny hairs, with sensory receptors grouped at the base of those hairs. When the researchers gently puffed on the hairs of a North American big brown bat, it fired off neurons in the bat's primary somatosensory cortex, which suggests that such sensory stimuli guide the animal during fast flight amid crazy wind patterns.
Aircraft may be able to adapt the basic principles from the bat's biology in new technology that could better detect and avoid air turbulence: Sensors that are particularly sensitive to changes in airflow, for example, which could make for a smoother, nimbler ride.
The technology can also be applied to unmanned air vehicles, like drones. In that case, aircraft could use their super tingly bat senses to avoid not only rough winds, but also obstacles like cliffs or trees, as the vehicle navigates complex terrain and dangerous environments.
Johns Hopkins' Dr Cynthia Moss, one of the study's researchers, says bats use wing adjustments to stabilise, slow down, and speed up. That's obviously unlike us humans, who simply walk around on a surface, but bats are mammals constantly moving in three dimensions.
"If aircraft were to have more sophisticated sensors, perhaps they could be more agile," she says. "They could be more carefully controlled if there were more feedback about the airflow in the flight."
Bats are the only mammals that can pull off powered flight (versus warm-blooded critters that fake-fly or glide, like a flying squirrel), and can hit speeds of 32km/h. Bats can fly like birds, but have mammalian advantages that make them extra dexterous demons in the sky.
Scientists already knew the importance of their hairs for flying, but this study is the first to highlight how crucial those touch receptors underneath are, and how they "touch" the air, "feeling" changes in airflow that they have to deal with.
"As humans, we don't think about how much touch really influences our movement," says Dr Moss. "If you were to build a Lego toy, for example, you could look at it, watch your fingers — but you need to actually feel the pressure on your fingers. You rely on touch to control your movement. It's the same with bats and flight."
The location of those receptors is also important for bats' rapid flight control. Bats are mammals belonging to the order Chiroptera ("hand wing"). And they have evolved in such a way that that their wings kind of resemble human hands. Unlike other mammals though, bats' "hands" grow out of the trunks of their bodies, which connects those touch sensors to the length of the spinal columns. So, their wings become super sensitive, not to mention multifunctional: they help the bats cradle young, grab food, even crawl on the ground.
We may not be close to commercial Batplanes, but bat-inspired, somersaulting drones could be a great start.
Pictures: Johns Hopkins University