Everyone and almost everything pees. Some things, it turns out, you do just by removing fluid from their backside at extremely high speed using a rectal stylus.
This highly unusual scenario summarizes the work of Georgia Institute of Technology researchers on how a leaf-hopping insect called the glassy-winged sharpshooter survives. While it may sound arcane, what they discovered may one day provide technological advances such as the rapid ejection of water from sensitive electronics.
Research into the sharpshooter’s excretion process began the way many scientific journeys begin: pure curiosity. Saad Bhamla, assistant professor of chemical and biomolecular engineering, observed that one of the insects would repeatedly form a perfectly round drop of liquid on its tail and then shoot it away at a blur of speed.
“Little is known about the fluid dynamics of excretion, despite its impact on animal morphology, energy and behavior,” Bhamla said in a statement. “We wanted to see if this tiny insect had come up with some clever engineering or physical innovation to pee this way.”
Studying the bug with high-speed video and microscopes revealed that the sharpshooter has a specific accessory that enables its impressive urination performance: an anal stylus that Bhamla called a “flashing butt.”
Bhamla compares this feature to the flippers of a pinball that the shooter uses to launch droplets of urine at incredible speed. The flicker can accelerate the liquid more than 10 times the pace of the fastest supercars.
“We realized that this insect had essentially evolved a spring and lever like a catapult, and that it could use these tools to hurl droplets of pee repeatedly at high accelerations,” explained Elio Chalita, a graduate student in bioengineering who worked with Bamla.
The team’s research is published in this week’s issue of the journal Nature Communications.
When the researchers measured the speed of the shaking droplets, they noticed that the pee droplets traveled even faster through the air than the train hit that launched them. This suggests the presence of superpropulsion, a phenomenon that has not been observed in physical systems until now.
Hyperpropulsion occurs when a rubber projectile receives an energy boost by synchronizing compression and launch time. One way to visualize this is to imagine a diver launching himself from a springboard at just the right moment to get the maximum boost from the spring effect. It appears that the sharpshooter’s stylus does something similar by compressing the droplet before launch, storing extra energy through surface tension in the liquid which then gives it a speed boost when you shake it.
Researchers believe that shaking is the most efficient way for sharpshooters to process the massive amount of plant juice they drink each day to survive — up to 300 times their body weight.
Urea helps you and me
Research into the bathing habits of sharpshooters could have some immediate benefits for humans because the insect is a major pest that causes millions of dollars in crop damage, especially in vineyards and citrus orchards in California and Florida. The species is expected to spread with climate change, and this new discovery could make it easier to track the species’ spread and inform knowledge that helps control their reproduction.
However, engineers may also learn from the biology of sharpshooters and develop new systems for launching water from portable electronic devices.
“What sharpshooters are dealing with would be like trying to throw away a beet-sized glob of maple syrup stuck to our hand,” said Miriam Ashley-Ross, a program director at the US National Science Foundation, which funded partially. the job. “The efficient method these tiny insects have evolved to solve the problem may lead to bio-inspired solutions for solvent removal in micro-industry applications such as electronics or rapid water removal from structurally complex surfaces.”
It’s crazy the things we can discover by taking a second to contemplate a drop of pee.
“This project reinforces the idea that science based on curiosity is valuable,” Challita said. “And the fact that we’ve discovered something so interesting — droplet superpropulsion in a biological system and heroic feats of physics that have applications in other fields — makes it all the more exciting.”