Super-fast Insect Urination Powered by the Physics of Superpropulsion “Little is known about the fluid dynamics of excretion, despite its impact on the morphology, energetics, and behavior of
sharpshooters – tiny pests notorious for spreading disease in crops – excrete the way they do. By using computational fluid dynamics and biophysical experiments, the researchers studied the fluidic, energetic, and biomechanical principles of Assistant Professor Saad Bhamla animals,” he said. excretion, revealing how an insect was in his backyard when he noticed smaller than the tip of a pinky something he had never seen finger performs a feat of physics and before: an insect urinating. bioengineering – superpropulsion. Although nearly impossible to Their research, published in see, the insect formed an almost Nature Communications, is the first perfectly round droplet on its observation and explanation of this tail and then launched it away so phenomenon in a biological system. quickly that it seemed to disappear. Studying how sharpshooters The tiny insect relieved itself use superpropulsion can also “We wanted to see if this tiny repeatedly for hours. provide insights into how to design insect had come up with any clever It’s generally taken for granted engineering or physics innovations in systems that overcome adhesion that what goes in must come out, order to pee this way.” - Saad Bhamla and viscosity with lower energy. so when it comes to fluid dynamics One example is low-power water(left, with Elio Chalita) in animals, the research is largely ejection wearable electronics, such focused on feeding rather than as a smart watch that uses speaker excretion. He and Bioengineering PhD vibrations to repel water from the But Bhamla had a hunch that student Elio Chalita investigated device. what he saw wasn’t trivial. how and why glassy-winged
Georgia Tech Engineers Develop Carbon Membranes Enabling Efficient Removal and Concentration of Organic Molecules from Water The need to remove organic contaminants from surface waters continues to grow due to an increasing influx from industrial, municipal, and agricultural sources. But these contaminants are challenging to remove outside of thermally driven separation processes, such as distilling or drying, which consume significant amounts of energy. However, researchers in ChBE@ GT have developed rigid, carbon membranes that effectively remove and concentrate small organic molecules (such as solvents) from water, based on the affinity between the organic species and carbon membrane. Published in Proceedings of the National Academy of Sciences, this
Traditionally, most membranes are designed to selectively permeate clean water while creating a highly concentrated organic waste stream that requires additional treatment. However, the unique behavior of these carbon membranes derived from a polymer of intrinsic microporosity developed by the Georgia Tech team has the unexpected ability to aldiscovery challenges conventional low the enhanced passage of organic molecules relative to that of water understanding, said Professor Ryan Lively. That’s because the new carbon molecules. membranes enable the permeation, rather than rejection, of organic mol- “This observation was unexpected ecules from aqueous mixtures, lead- and puzzling for several months, and ing to their higher concentration in we were highly skeptical of these the membrane permeate compared findings.” - lead author Haley White to the membrane feed. (ChBE PhD 2022). CHBE.GATECH.EDU 5
