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Pig Skin Outshines Synthetic Alternatives in Puncture Resistance Study
Recent research has unveiled that thin, elastic skin—such as that from pigs and humans—significantly mitigates damage from punctures. Remarkably, pig skin surpasses synthetic materials designed to imitate biological skin in terms of puncture resistance. The study highlights the skin’s ability to dissipate the energy from puncturing objects, ultimately protecting deeper tissues from injury.
The findings are detailed in the Journal of the Royal Society Interface.
The research was spearheaded by Philip Anderson, a professor at the University of Illinois Urbana-Champaign, alongside postdoctoral researcher Bingyang Zhang. Their interest lies in how the principles of physics shape evolutionary traits, prompting an investigation into the mechanics of puncture—a phenomenon encountered throughout the natural world.
Anderson remarked, “Puncturers exist across numerous organisms, including vertebrates, invertebrates, and even plants and fungi, each employing various sharp implements like fangs and claws to penetrate.” This ubiquitous need to puncture signifies the importance of understanding the dynamics at play.
However, Anderson noted that isolating the various factors involved in puncturing—such as the speed and shape of the object—presents significant challenges. The team began their inquiries by employing 3D-printed cones with differing profiles to serve as puncturing tools against silicone gels that varied in density. Having addressed some foundational questions regarding the physics involved in puncture mechanics, Anderson’s laboratory is now expanding its research to examine biological materials more closely.
In a subsequent phase of the research, Zhang evaluated the puncture resistance of pork slabs both with and without skin, drawing comparisons with synthetic counterparts made of silicone gel designed to mimic the rigidity of natural tissues. Notably, the real pig skin measured approximately 2.5 mm thick compared to a synthetic skin that was about 4 mm thick. Despite this thickness discrepancy, the experiments revealed that genuine pig skin consistently outperformed its synthetic substitute during various projectile speed tests.
Through a combination of dynamic puncture experiments and theoretical modeling, Zhang stated, “We assessed the puncture resistance of natural skin compared to synthetic materials. Surprisingly, we found that pig skin was able to reduce puncture damage by around 60% at slower impact speeds and 73% at higher speeds when attached to underlying tissues.” In contrast, synthetic skin was less effective, offering protection that did not exceed 40% at lower speeds and 30% at higher speeds.
“These results clearly highlight the superior biomechanical properties inherent in natural skin,” Zhang added.
Anderson emphasized the efficacy of skin in resisting punctures, noting, “At lower speeds, the effective resistance was so high that the projectile could not even penetrate the skin.” This remarkable resilience can be attributed to the structure of skin, primarily composed of collagen fibers that provide strength and flexibility. Even when some collagen fibers rupture, the network still offers resistance, while also dispersing energy from the projectile, thereby reducing its penetration depth—a characteristic absent in silicone gel.
“Our findings illustrate how natural skin can effectively redistribute forces and dissipate energy, serving as a remarkable defense mechanism,” Zhang concluded. “We also gained valuable insights into the limitations of synthetic materials, which, while useful in various contexts, struggle to replicate the intricate functions of biological tissues.”
This investigative effort received support from the National Science Foundation. Bingyang Zhang has since taken up a postdoctoral position at Cornell University.
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