Surfaces repair themselves automatically in safer, more durable structures.

Drawing from inspiration in nature, Dr. Pinar Akcora, Assistant Professor of Chemical Engineering and Materials Science, is using her National Science Foundation (NSF) CAREER Award to study the self-healing properties of nanoparticles and develop a foundation for diverse applications in "smart materials" resistant to wear even in hostile environments or conditions.

Dr. Pinar AkcoraA new faculty member at Stevens Institute of Technology, Dr. Akcora was a co-author for a paper in Nature Materials in 2009 in which the research team studied the self-assembly properties of nanoparticles. As a polymer chemist, she was responsible for deducing how the particles organized when introduced into a polymer system. Dr. Akcora is now investigating how to make nanoparticles with new properties, especially magnetism, that will enable them to be more complex and have unique properties, such as self-healing.

Self-healing, so-called "living" materials currently exist, but most require some outside force or a built-in chemical delivery system in order for the system to be restored. For magnetic materials, that might mean the application of an electrical field to reorient particles on the surface. Other solid materials can be manufactured with microcapsules full of chemicals that are released when the material is disturbed.

Although these structures have potential, "such systems are really quite difficult to make," Dr. Akcora states, and they require constant intervention. Her projects are taking "smart" materials beyond "stimulus-response" healing and towards materials that are built to automatically restore themselves when disturbed or damaged.

"In our system, we don't say that these materials react to environmental stimuli. We just say that magnetic forces are compelled to maintain the structural equilibrium."

In her lab, Dr. Akcora and a team of undergraduate and graduate students are fabricating nanoparticles and embedding them in polymers to reveal their properties. The particle chains she is developing as part of her CAREER Award have demonstrated three significant properties. They have multi-functional assembly, are conductive and therefore potentially magnetic, and they are mechanically strong. With this set of characteristics, the materials are resistant to wear, can be employed in rough conditions such as the coating on a car or airplane, and can be used in electrical membranes or sensors.

Dr. Akcora's materials have practically innumerable applications, with the potential to provide self-healing properties to everything from thin film batteries to car paint.

As a new member of the community at Stevens, The Innovation UniversityTM, Dr. Akcora is excited to work with a diverse population of scientists and engineers accustomed to multi-disciplinary collaboration. A focus on nanotechnology throughout the university has allowed many to align their research with these extremely small and extremely versatile materials. Ongoing collaborations between materials scientists and biomedical engineers have already demonstrated synergy specifically between these two disciplines; Dr. Akcora's smart materials, laid in a biocompatible polymer, have wide-ranging application in biomedical devices.

Dr. Akcora's technology is still in the earliest stages of development, but she finds the project rewarding even at the level of fundamental research. While she is carefully observing the dynamic assembly behaviors of particles created in her lab, she is also cultivating relationships with future collaborators who will bring the self-healing materials to market in countless useful products.

"I think these materials promise to have a lot of benefit to the field," Dr. Akcora says. "I look forward to seeing the applications developed further to incorporate this technology."