2023-02 ジョージア工科大学
高速ビデオと顕微鏡を使用し、彼らは尿を排出するためのバイオメカニクスと物理学の原理を調べ、虫がスーパープロパルジョンと呼ばれる物理原理を使用して、高加速で尿を排出することがわかりました。さらに、その結果は、シャープシューターがエネルギー制約の中で効率的に排泄するために使用する最もエネルギー効率の高い方法であることがわかりました。
この研究は、自然科学誌Nature Communicationsに掲載されました。
<関連情報>
- https://research.gatech.edu/super-fast-insect-urination-powered-physics-superpropulsion
- https://www.nature.com/articles/s41467-023-36376-5
エネルギー的に制約のある昆虫における液滴の超伝導 Droplet superpropulsion in an energetically constrained insect
Elio J. Challita,Prateek Sehgal,Rodrigo Krugner & M. Saad Bhamla
Nature Communications Published:28 February 2023
DOI:https://doi.org/10.1038/s41467-023-36376-5
Abstract
Food consumption and waste elimination are vital functions for living systems. Although how feeding impacts animal form and function has been studied for more than a century since Darwin, how its obligate partner, excretion, controls and constrains animal behavior, size, and energetics remains largely unexplored. Here we study millimeter-scale sharpshooter insects (Cicadellidae) that feed exclusively on a plant’s xylem sap, a nutrient-deficit source (95% water). To eliminate their high-volume excreta, these insects exploit droplet superpropulsion, a phenomenon in which an elastic projectile can achieve higher velocity than the underlying actuator through temporal tuning. We combine coupled-oscillator models, computational fluid dynamics, and biophysical experiments to show that these insects temporally tune the frequency of their anal stylus to the Rayleigh frequency of their surface tension-dominated elastic drops as a single-shot resonance mechanism. Our model predicts that for these tiny insects, the superpropulsion of droplets is energetically cheaper than forming jets, enabling them to survive on an extreme energy-constrained xylem-sap diet. The principles and limits of superpropulsion outlined here can inform designs of energy-efficient self-cleaning structures and soft engines to generate ballistic motions.
