UT Dallas engineers have developed new structures that are even stronger than Kevlar, a synthetic fiber widely used in bulletproof vests. The new structures are able to stretch approximately seven times their length.
Absorbs up to 98 joules per gram
Led by Dr. Majid Minary, an assistant professor of mechanical engineering, the researchers relied on a previous study about the piezoelectric action (the idea that pressure forms electric charges) of collagen fibers to guide them.
“We reproduced this process in nanofibers by manipulating the creation of electric charges to result in a lightweight, flexible, yet strong material,” said Minary in a statement. “Our country needs such materials on a large scale for industrial and defense applications.”
Using PVDF
The engineering team used fluoride (PVDF) and its co-polymer, polyvinvylidene fluoride trifluoroethylene (PVDF-TrFE), to spin nanonofibers. The researchers created yarns by twisting the fibres and then into coils by twisted them further.
“It’s literally twisting, the same basic process used in making conventional cable,” Minary, a member of the Alan G. MacDiarmid NanoTech Institute, explained.
The final step involved measuring the mechanical properties of the yarn and coils. “Our experiment is proof of the concept that our structures can absorb more energy before failure than the materials conventionally used in bulletproof armors,” said Minary, whose recent research was published in the ACS Applied Materials and Interfaces journal . “We believe, modeled after the human bone, that this flexibility and strength comes from the electricity that occurs when these nanofibers are twisted.”
The engineers hope their new structures can be used for defence applications, including in military planes. Minary and his team plan to continue their research and make larger structures out of the yarns and coils.