It looks like the writers of Superman IV weren’t too far from the truth when they added the detail that a single strand of Superman’s hair could suspend a 1,000-pound wrecking ball. Real human hair is extremely strong as well — not as strong as the Man of Steel’s, but it does have a strength to weight ratio that’s comparable to actual steel.
This discovery was made by University of California, San Diego scientists who recently published their findings in the journal Materials Science and Engineering: C. The researchers studied how hair responds when it’s deformed or stretched and how it’s so damn strong — a full head of hair could support the suspended weight of two elephants. They hope to use this better understanding of hair as “common material with many fascinating properties” to create new materials for strength-necessary items, like body armor.
When the team examined hair at a nanoscale level they found that the faster hair is stretched, the stronger it becomes. In fact, it can be stretched 1.5 times its original length before it breaks. The researchers also discovered that hair can recover its original shape when stretched a bit; when stretched by a lot, hair has an irreversible “structural transformation.”
Wet hair is even stronger — hair in higher humidity levels can withstand being stretched 70 to 80 percent past its normal length before it breaks. Heated hair meanwhile doesn’t become permanently damaged until it’s heated to 140 degrees Fahrenheit.
Hair’s strength comes down to its unique structure. Hair has a cortex, which is made of parallel fibrils, and a corresponding matrix. The way these two parts work together is what helps hair withstand stress and strain. As hair is put through tests like heat and stretching, the spiral-shaped chains of molecules that make up hair go through a period of structural change before eventually breaking.
With more research, the scientists hope they can mimic the way hair structurally changes and withstands to create stronger, more efficient materials.
“Nature creates a variety of interesting materials and architectures in very ingenious ways,” lead author Marc Meyers said in a statement, “We’re interested in understanding the correlation between the structure and the properties of biological materials to develop synthetic materials and designs — based on nature — that have better performance than existing ones.”
Hair is just the latest in a growing list of biological materials scientists are examining in order to create high performing replacements. Spider silk in particular has been heralded as a material of the future, with hopes that its strength properties could be applied to bulletproof vest technology. Researchers hope to produce synthetic hangfish slime and apply that to bulletproof fabric as well, while MIT researchers are studying sea sponges and bones to create more durable concrete.