Australian scientists have uncovered the reason why human skin wrinkles up but doesn’t just melt away in hot bath water.
The scientists’ findings were recently published in the Journal of the Royal Society Interface.
“When we are in the bath and we have been there for a while the stratum corneum [outside] layer of our skin expands. This causes wrinkles and means our finger prints will be enlarged also,” Myfanwy Evans of the Australian National University in Canberra explained during an interview with the Australian ABC news corporation.
Mysterious properties of skin
Researchers have long been mystified that skin doesn’t just gradually disintegrate when soaked in water. Evans and her colleagues created a series of experiments designed to find the reason that skin retains its integrity.
“We’re coming at it from a completely geometric point of view in order to try and explain some of the phenomena that are seen in skin,” said Evans.
In the past, researchers studying the properties of human skin believed that the stratum corneum had a structure that was capable of expanding when it absorbed water. Yet why the skin itself failed to fall apart when it expanded stumped them.
Evans and her team decided to study the skin’s structures including the stratum corneum with computer modeling. Their investigation discovered the unique structure of skin and why it doesn’t fall apart when immersed.
“Our model provides an explanation as to why the skin maintains its structural rigidity and expansion in water,” Evans said, “which was something that was never quite able to be explained.”
Amazing 3D structure weaves skin together
The modeling revealed the stunning information that the stratum corneum is composed of helical fibers made of keratin. The fibers are intricately woven into a 3D mosaic. The nature of the weave permits the keratin to mimic a sponge—soaking up water while still retaining its integrity. As the skin absorbs the water the fibers keep the skin from literally falling apart.
“Contact between fibers are what gives the material structural stability,” Evans explained. “In this expansion all of those inter-fiber contacts are maintained so the material stays as a rigid material.”
She voiced a strong word of caution, however. The weave can maintain the integrity of the skin for only so long. She said that after 24 hours of continuous exposure to water that irreversible damage may occur.
This new insight into the nature of the skin’s mechanisms may lead to materials being created that incorporate the same valuable properties.
