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: Machine learning algorithm makes impossible screening of advanced materials possible

More information: The paper, "Three-Dimensional Microvascular Fiber-Reinforced Composites," is available online at onlinelibrary.wiley.com/doi/10… 2/adma.201100933/pdf

Related Stories

Unraveling cell division

10 hours ago

CRG researchers shed new light on mitosis. The study published in the Journal of Cell Biology describes how Topo 2 disentangles DNA molecules and is essential for proper cell division

Making quantum dots glow brighter

8 hours ago

Researchers from the University of Alabama in Huntsville and the University of Oklahoma have found a new way to control the properties of quantum dots, those tiny chunks of semiconductor material that glow ...

For electronics beyond silicon, a new contender emerges

6 hours ago

Silicon has few serious competitors as the material of choice in the electronics industry. Yet transistors, the switchable valves that control the flow of electrons in a circuit, cannot simply keep shrinking ...

Recommended for you

A dye with tunable optical characteristics

Sep 12, 2014

Researchers from RIKEN and the University of Tokyo have developed an organic dye molecule with tunable light-absorption and color characteristics. This development promises to open the door to the creation ...

How salt causes buildings to crumble

Sep 11, 2014

Salt crystals are often responsible when buildings start to show signs of aging. Researchers from the Institute for Building Materials have studied salt damage in greater depth and can now predict weathering ...

Ridding the sea and land from toxic plastics fragments

Sep 11, 2014

Plastic products made of PVC, Polystyrene and other prominent plastics are flooding the market. They are a growing threat to the environment, as they are found in the sea or dumped in land fills. But in a ...

User comments : 0