Chip on the old block

University of Illinois researchers have developed synthetic materials that can actually repair themselves by mimicking the healing process of the human body.

The new self-repairing materials are imbedded with interconnected microchannels, similar to the human system of blood vessels. If the material sustains sudden damage, two liquids flow separately into the vascular system and travel to the damaged area. When the liquids come together at the site of damage, a chemical reaction quickly turns the liquids into a gel, much the same way blood clots around an injury. As the gel conforms to the shape of the damaged material, it hardens.

The speed of either the gelling or hardening can be increased or decreased to enable repair of different types of damage. For example, repairing a hole might require a different processing speed than repairing hairline cracks.

Scott White, professor of aerospace engineering at the University of Illinois and lead researcher, envisions a day when self-healing systems will be used in interplanetary space ships, or satellites, where it would be impossible to send a repair crew. Regenerative materials could be used to produce self-healing cars in which the paint never chips, cracks, or fades, and for airplanes that can heal their own cracks and holes, providing increased safety and reduced maintenance.

“I see a world, in the future, where ruptured oil and gas pipelines are a thing of the past because the materials used self-heal in response to corrosion and fatigue,” White said.

Coffee catch

Coffee is bad. Coffee is good. Experts have blamed it for stunted growth, heart disease, and cancer, and credited it with protecting against Parkinson’s disease, Type 2 diabetes, and liver disease.

Now researchers at the Harvard School of Public Health and Brigham and Women’s Hospital may have reconciled the warring studies. They conclude people respond differently to coffee based on their genes.

The researchers conducted a study of more than 120,000 regular coffee drinkers, identifying six genetic variants that contribute to how people respond to coffee and caffeine.

Lead author Marilyn Cornelis says, “Our findings may allow us to identify subgroups of people most likely to benefit from increasing or decreasing coffee consumption for optimal health.” —J.B.

Prosthetic touch

Prosthetic hands can actually produce feelings of touch through new technology developed by researchers at Case Western Reserve University and the Louis Stokes Cleveland VA Medical Center.

Because the sense of touch occurs in the brain, not in the hand, researchers found a way to stimulate the brain to produce touch sensations. They tape sensors to a prosthetic hand. When touched, the sensors send electric signals to a computer that transmits signal patterns to electrodes attached to a subject’s arm. The nerves in the arm send the signals to the brain.

Study participant Igor Spetic experienced sensation in 19 different locations on his prosthetic hand. He distinguished taps, pressure, light movement, and vibration, as well as the difference between smooth, rigid, and rough textures.

Dustin Tyler, associate professor of biomedical engineering at Case Western Reserve and director of the research, hopes that within the next five years his team will develop a system that works outside the lab and in a patient’s home.

“I would love to feel my wife’s hand again,” Spetic said. “Just to hold hands would be the ultimate.” —J.B.