Vascular composites enable dynamic structural materials

Jul 26, 2011

Taking their cue from biological circulatory systems, University of Illinois researchers have developed vascularized structural composites, creating materials that are lightweight and strong with potential for self-healing, self-cooling, metamaterials and more.

"We can make a material now that's truly multifunctional by simply circulating fluids that do different things within the same material system," said Scott White, the Willet Professor of who led the group. "We have a vascularized structural material that can do almost anything."

are a combination of two or more materials that harness the properties of both. Composites are valued as structural materials because they can be lightweight and strong. Many composites are fiber-reinforced, made of a network of woven fibers embedded in – for example, graphite, fiberglass or Kevlar.

The Illinois team, part of the Autonomous Materials Systems Laboratory in the Beckman Institute for Advanced Science and Technology, developed a method of making fiber-reinforced composites with tiny channels for liquid or gas transport. The channels could wind through the material in one long line or branch out to form a network of capillaries, much like the vascular network in a tree.

"Trees are incredible , but they're dynamic too," said co-author Jeffrey Moore, the Murchison-Mallory professor of chemistry and a professor of materials science and engineering. "They can pump fluids, transfer mass and energy from the roots to the leaves. This is the first step to making synthetic materials that have that kind of functionality."

The key to the method, published in the journal Advanced Materials, is the use of sacrificial fibers. The team treated commercially available fibers so that they would degrade at high temperatures. The sacrificial fibers are no different from normal fibers during weaving and composite fabrication. But when the temperature is raised further, the treated fibers vaporize – leaving tiny channels in their place – without affecting the structural composite material itself.

"There have been vascular materials fabricated previously, including things that we've done, but this paper demonstrated that you can approach the manufacturing with a concept that is vastly superior in terms of scalability and commercial viability," White said.

In the paper, the researchers demonstrate four classes of application by circulating different fluids through a vascular composite: temperature regulation, chemistry, conductivity and electromagnetism. They regulate temperature by circulating coolant or a hot fluid. To demonstrate a chemical reaction, they injected chemicals into different vascular branches that merged, mixing the chemicals to produce a luminescent reaction. They made the structure electrically active by using conductive liquid, and changed its electromagnetic signature with ferrofluids – a key property for stealth applications.

Next, the researchers hope to develop interconnected networks with membranes between neighboring channels to control transport between channels. Such networks would enable many chemical and energy applications, such as self-healing polymers or fuel cells.

"This is not just another microfluidic device," said co-author Nancy Sottos, the Willett professor of science and engineering and a professor of aerospace engineering. "It's not just a widget on a chip. It's a structural material that's capable of many functions that mimic biological systems. That's a big jump."

Explore further: Chemical deterrent from snow fleas identified

More information: The paper, "Three-Dimensional Microvascular Fiber-Reinforced Composites," is available online at onlinelibrary.wiley.com/doi/10.1002/adma.201100933/pdf

Related Stories

Google unveils Android's latest technological tricks

38 minutes ago

Google's next version of its Android operating system will boast new ways to fetch information, pay merchants and protect privacy on mobile devices as the Internet company duels with Apple in the quest to ...

Bacteria renew mystery over Chilean poet Neruda's death

50 minutes ago

Family of Chilean poet Pablo Neruda said Thursday forensic experts have found evidence of a massive bacterial infection in his remains, increasing their suspicion that he was poisoned by dictator Augusto Pinochet's regime.

Recommended for you

Chemical deterrent from snow fleas identified

May 29, 2015

Snow fleas keep predators at bay with a chemical deterrent. German scientists have now isolated this compound and identified it by means of spectroscopic analysis and X-ray crystallography. In the journal ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.