Scott R. White’s Self-Healing Circuits
Scott R. White has an unusual distinction for a scientist: His work has inspired jokes on late-night TV. Researchers “have developed a plastic that repairs itself,” said Jay Leno during a monologue in February 2001. “If it cracks or breaks, it automatically mends itself. … That means Cher could finally achieve immortality.”
“I found it hilarious,” says White, a professor of aerospace engineering at the University of Illinois at Urbana-Champaign. At the time of Leno’s crack, he and his colleague Nancy R. Sottos had just published a paper detailing how to create self-healing materials, like paint that instantly repairs scratches and dings. In December 2011, he announced that his lab had successfully applied the same idea to electronic circuits. That could be a big deal: “Semiconductor factories yield 80 percent good product at the end of the fabrication process,” says Risto J. Puhakka, president of VLSI Research, a semiconductor market research company. “A 1 percent improvement would have a big financial impact.”
The technology developed by White and Sottos during the late 1990s and early 2000s consists of globules so small they can be seen only with a powerful electron-scanning microscope. They’re filled with some of the chemical building blocks of plastic and can be applied to the surface of epoxies like paint. When the epoxy is scratched or fissures, the capsules rupture and release their gluey cargo into the damaged area, instantly mending it. In 2005, White founded Autonomic Materials to create products for industries including autos, aerospace, and oil exploration. The company has raised $4 million from investors and anticipates its first sales this year. Chief Executive Officer Joe Giuliani won’t name clients due to nondisclosure agreements.
In 2010, White joined a group at Argonne National Laboratory to create self-healing batteries. Batteries are believed to die because of the loss of electrical conductivity. In late 2011, White’s group demonstrated a simple circuit covered by micro-capsules containing a liquid metal. When the circuit breaks, the conductive metal fills the gap in less than a millisecond. Argonne now plans to build a prototype battery, and White says semiconductors using self-healing technology could be available in five years.
White says his parents realized early on that he’d be an engineer or scientist. At age 10, while growing up in a small town in Missouri, he got a new bike as a present, then promptly disassembled it to see how it worked. He studied mechanical engineering at the Missouri University of Science and Technology and earned his PhD in materials science at Penn State in 1990.
He likes the idea of materials that behave more like biological systems, because his dance teacher mother taught him to appreciate the body. He envisions products that grow and change organically, the way bones and organs do. “Maybe we’ll build bridges that continuously remodel themselves with parts that are never older than 10 years,” he says.