New energy-absorbing metal structure is inspired by Asian fruit AACHEN, Germany, Dec. 3 (UPI) -- German scientist say a new energy-absorbing metal structure was inspired an Asian citrus fruit than can survive a 30-foot fall from its tree. Researchers from the RWTH Aachen University and the University of Freiburg have reported the development of an aluminum hybrid that could be used to optimize technical components and safety materials, taking their inspiration from an unexpected source -- the peel of the pomelo fruit of South and Southeast Asia. Pomelo fruits can weigh as much as 4 pounds but can withstand impact forces resulting from long falls due to the hierarchical structuring of the peel, which is made up of a graded, fiber-reinforced foam, they said. Their new aluminum hybrid is the product of a bio-inspired approach, combining metals with different mechanical properties mimicking the naturally occurring structures of the pomelo peel that give it its strength, they said. This hybrid consists of highly ductile pure aluminum in the center and a high-strength aluminum-silicon alloy in the outer shell, each providing different qualities to the final material. "The demands of designers and consumers on forthcoming components will be increased in the future," Aachen researcher Sebastian F. Fischer said. "The main reason for this is the need for energy-saving, light-weight products, especially in the automotive industry," he said. And while the development of new materials is increasingly difficult, the joining of different materials with different properties holds a lot of promise. The research has been published in the Journal of Materials Science.