New Material for Automotive Skin is Based on Bone Biology

Researchers at Bayer MaterialScience may have lightened the weight of future cars with a new sandwich-structured plastic that is modeled after ideas found in nature.

Showcased at the K 2013 plastics trade fair, Bayer MaterialScience has developed a prototype car trunk lid using an innovative lightweight plastic that is inspired by the structure of bone. The material has a light foamed core and a smooth hard shell, giving it both absorptive properties and a stiff, smooth exterior.

The skin is highly resistant to minor damage and also provides good thermal and sound insulation, thereby improving energy management and providing a quieter driving experience in the vehicle. The material can be coated to achieve the final look.  Other components, such as antennas and lighting, can be integrated into the design.

“To make the outer layer, continuous glass fiber mats are impregnated with a thermoplastic polymer formulated from polycarbonate. All the fibers are wetted and fully coated by the plastic matrix,” said team leader Ulrich Grosser. “This is the key to high stiffness of the edge layers in a sandwich structure.” The skin is then formed into the appropriate shape and the core is filled with Baysafe low-density polyurethane foam.

The team further drew on biomimetic inspiration in developing the trunk’s mounting system. “To find a solution, we studied how trees are anchored to the forest floor. A network of roots lends even tall and heavy trees a secure hold in soil that is frequently soft,” Grosser explained. From there the team used CAD to demonstrate how a plastic structure resembling roots could be successfully secured to the lightweight foam core.

While their prototype was designed specifically for the automotive industry, the team believes that their product could have many applications. According to Dr. Olaf Zollner, the Head of Application Technology, “the auto industry often leads the way in pioneering technical developments, but we are also looking forward to talks with customers and partners in other industries. Such lightweight and stiff composites made from polycarbonate blends are excellently suited to the fabrication of ultrabooks and other high-tech products.”

Images Courtesy of Bayer MaterialScience