CHAMPAIGN, Ill. — Researchers have created a model that can calculate the energy involved when one organism stabs another with its fangs, spines, spines, or other piercing parts. Because the model can be applied to a variety of organisms, it will help scientists study and compare many types of biological punch tools, the researchers said. It will also help engineers develop new systems to effectively pierce materials or resist drilling.
The new findings are reported in the Journal of the Royal Society Interface.
Zhang tested the model using a projectile piercing a gelatinous material that mimics animal tissue.
Photo by Fred Zwicky
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“The idea behind this was to provide a quantitative framework for comparing a variety of biological puncture systems with each other,” said Philip Anderson, professor of evolution, ecology and behavior at the University of ‘Illinois at Urbana-Champaign, who conducted the postdoctoral research. researcher Bingyang Zhang. “A first question of this research was how to measure these different systems to make them comparable.”
“It’s a difficult problem to predict the properties of biological systems,” Zhang said.
Animals and plants deploy a variety of strategies to stab their prey or defend themselves against other organisms, and even those that use similar strategies or tools modify those tools to suit their specific needs, the researchers said. Their targets also differ.
“In vipers, for example, some bite mammals, which means they have to puncture the soft tissues enclosed in the skin, while others target reptiles, which have scales, which makes them stiffer and more rigid. harder to break through,” said Anderson, who studies mechanics and energetics. biological puncture systems.
Some parasitoid wasps, such as those of the genus Ichneumoncan use their ovipositors to stab wood.
Photo by US Fish & Wildlife Service
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Other organisms, like parasitoid wasps, can use their ovipositors to burrow through caterpillar skins, but can also penetrate fruit or even wood, he said.
To develop a model that can be applied to a variety of systems, Zhang determined the key factors that must be included in any calculation of the energetics involved. These include changes in kinetic energy when the punch tool is used, but also take into account the material properties of the target tissue.
A red-headed woodpecker uses its beak to pierce through wood.
Photo by Andy Reago and Chrissy McClarren, CC BY-SA 2.0
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It involves calculations describing how the initial kinetic energy drives a puncture tool into a material, opening up new surfaces in the material as the fracture propagates. It also takes into consideration the frictional resistance and elasticity of the target tissue.
The calculations were aimed at conical puncture tools, which are common in biological systems, the researchers said.
Anderson is deploying the new model to aid in his studies of puncturing organisms like viper fangs, stingray spines, and parasitoid wasp ovipositors.
“If we know the morphology or shape of damage created by a puncture tool, we can use this model to predict the amount of energy expended during a puncture scenario,” Zhang said. “Or we can predict different aspects of material property, for example, how it will fracture, which will be useful in engineering and biological applications.”
The National Science Foundation supports this research.