What Are 'Smart' Metals and How Are They Revolutionizing the Way Alloys Are Used

Metals have often been overlooked as a viable field for innovation, but materials scientist Ainissa Ramirez is helping to change that. Her groundbreaking research has resulted in new ways to control and shape metals into materials that can be put to practical everyday use - from producing stronger circuitry for cell phones to developing more efficient medical devices that save lives. "The diverse applications of these metals have made them increasingly important and visible to the world," says Ainissa, associate professor of Mechanical Engineering at Yale University where research on shape memory alloys -- the so-called "smart materials" -- and on a solder which can be manipulated into place with a magnetic field keep her extremely busy.

Ramirez is known for discovering a universal solder (a fusible metal alloy used to join metallic parts) that can bond metals to ceramics, glass, diamonds, and the oxide materials used in semiconductor fabrication. She also developed thin film shape-memory alloys, which have the unique capability of "remembering" and reverting back to their original shape. Says Ainissa: "My work is in understanding these alloys, particularly their thin film behavior, and integrating them into microelectromechanical systems (or MEMS). These materials are now being used to help move liquids or blood in medical devices."

Inspiration for her research can come in unexpected ways -such as while working with a student who needed a project for his senior project. "The original goal for the project was to find a way to strengthen solder, but we ended up with something much greater -- a strong, inexpensive material that can replace traditional lead-based solders, which have been banned in many electronic products." The collaboration resulted in developing a non-toxic magnetic solder (replacing lead-based materials and the then-popular but weaker tin-silver alloy) that can be manipulated in three dimensions and selectively heated. When melted, the solder can then be easily and cheaply channeled with a magnet to connect transistors, chips and other components.

Can you suggest some other uses for 'smart' metals?

Read more about Ainissa and her other scientific achievements here.

Hear this cool NOVA 'Making Stuff Work' podcast featuring an interview w/Ainissa.