Researchers at North Carolina State University have developed a new metallic bubble wrap that is lighter, stronger and more flexible than sheet metal and more heat- and chemical-resistant than plastic or other polymer-based bubble wraps. Potential applications include automobile body panels, the wing edges of airplanes, suitcases, helmets, and cases for computers and other electronic devices.
Dr. Afsaneh Rabiei, professor of mechanical and aerospace engineering and the lead researcher on the project, developed the metallic bubble wrap to offer protection in areas that are only a few millimeters thick. To be effective, such materials must be thin enough to fit inside tightly spaced product linings, flexible enough to withstand twisting and bending, and strong enough to protect the contents inside.
To create the bubble wrap, Rabiei started with a thin sheet of aluminum and used a studded roller to dot the material with small indentations. Then she deposited a foaming agent — such as calcium carbonate or titanium hydrate — into the indentations. When heated, such agents decompose and create bubbles.
Rabiei covered the aluminum with another sheet, sandwiching the foaming agent in its indentation troughs. She ran a heavy roller over the two sheets to bond them together. In the final step, she placed the combined sheet into a furnace, where the heat broke down the foaming agent and created air bubbles in the material.
Also: Learn about Preparation of a Bimetal Using Mechanical Alloying.