Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Now, self-healing materials can mimic human skin, healing again and again

The next generation of self-healing materials, invented by researchers at the University of Illinois, mimics human skin by healing itself time after time. The new materials rely upon embedded, three-dimensional microvascular networks that emulate biological circulatory systems.

"In the same manner that a cut in the skin triggers blood flow to promote healing, a crack in these new materials will trigger the flow of healing agent to repair the damage," said Nancy Sottos, a Willett Professor of materials science and engineering, and the corresponding author of a paper accepted for publication in the journal Nature Materials, and posted on its Web site.

"The vascular nature of this new supply system means minor damage to the same location can be healed repeatedly," said Sottos, who also is a researcher at the university's Beckman Institute.

In the researchers' original approach, self-healing materials consisted of a microencapsulated healing agent and a catalyst distributed throughout a composite matrix. When the material cracked, microcapsules would rupture and release healing agent. The healing agent then reacted with the embedded catalyst to repair the damage.

"With repeated damage in the same location, however, the supply of healing agent would become exhausted," said Scott White, a Willett Professor of aerospace engineering and a researcher at the Beckman Institute. "In our new circulation-based approach, there is a continuous supply of healing agent, so the material could heal itself indefinitely."

To create their self-healing materials, the researchers begin by building a scaffold using a robotic deposition process called direct-write assembly. The process employs a concentrated polymeric ink, dispensed as a continuous filament, to fabricate a three-dimensional structure, layer by layer.

Once the scaffold has been produced, it is surrounded with an epoxy resin. After curing, the resin is heated and the ink - which liquefies - is extracted, leaving behind a substrate with a network of interlocking microchannels.

In the final steps, the researchers deposit a brittle epoxy coating on top of the substrate, and fill the network with a liquid healing agent.

In the researchers' tests, the coating and substrate are bent until a crack forms in the coating. The crack propagates through the coating until it encounters one of the fluid-filled "capillaries" at the interface of the coating and substrate. Healing agent moves from the capillary into the crack, where it interacts with catalyst particles.

If the crack reopens under additional stress, the healing cycle is repeated.

"Ultimately, the ability to achieve further healing events is controlled by the availability of active catalyst," said Kathleen S.
Toohey, a U. of I. graduate student and lead author of the paper.
"While we can pump more healing agent into the network, 'scar tissue'
builds up in the coating and prevents the healing agent from reaching the catalyst."

In the current system, the healing process stops after seven healing cycles. This limitation might be overcome by implementing a new microvascular design based on dual networks, the researchers suggest.

The improved design would allow new healing chemistries - such as two-part epoxies - to be exploited, which could ultimately lead to unlimited healing capability.

"Currently, the material can heal cracks in the epoxy coating - analogous to small cuts in skin," Sottos said. "The next step is to extend the design to where the network can heal 'lacerations' that extend into the material's substrate."

With Sottos, Toohey and White, the paper's other co-authors are Jennifer Lewis, the Thurnauer Professor of Materials Science and Engineering and interim director of the Frederick Seitz Materials Research Laboratory, and Jeffrey Moore, a William H. and Janet Lycan Professor of Chemistry and a researcher at the Frederick Seitz Materials Research Laboratory and Beckman Institute. White, Sottos and Moore co-invented self-healing plastic; Lewis and White pioneered direct ink writing of three-dimensional microvascular networks.

The work was funded by the U.S. Air Force Office of Scientific Research and the Beckman Institute.

James E. Kloeppel | University of Illinois
Further information:

More articles from Materials Sciences:

nachricht From ancient fossils to future cars
21.10.2016 | University of California - Riverside

nachricht Study explains strength gap between graphene, carbon fiber
20.10.2016 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>