Looking at a smooth sheet of plastic in one University of Illinois laboratory, no one would guess that an impact had recently blasted a hole through it.
Illinois researchers have developed materials that not only heal, but regenerate. Until now, self-repairing materials could only bond tiny microscopic cracks. The new regenerating materials fill in large cracks and holes by regrowing material.
Photo by Ryan Gergely
Illinois researchers have developed materials that not only heal, but regenerate. The restorative material is delivered through two, isolated fluid streams (dyed red and blue). The liquid immediately gels and later hardens, resulting in recovery of the entire damaged region. This image is halfway through the restoration process.
Led by professor Scott White, the research team comprises professors Jeffry S. Moore and Nancy Sottos and graduate students Brett Krull, Windy Santa Cruz and Ryan Gergely. They report their work in the May 9 issue of the journal Science.
“We have demonstrated repair of a nonliving, synthetic materials system in a way that is reminiscent of repair-by-regrowth as seen in some living systems,” said Moore, a professor of chemistry.
Such self-repair capabilities would be a boon not only for commercial
goods – imagine a mangled car bumper that repairs itself within minutes of an accident – but also for parts and products that are difficult to replace or repair, such as those used in aerospace applications.
The regenerating capabilities build on the team’s previous work in developing vascular materials. Using specially formulated fibers that disintegrate, the researchers can create materials with networks of capillaries inspired by biological circulatory systems.
“Vascular delivery lets us deliver a large volume of healing agents – which, in turn, enables restoration of large damage zones,” said Sottos, a professor of materials science and engineering. “The vascular approach also enables multiple restorations if the material is damaged more than once.”
For regenerating materials, two adjoining, parallel capillaries are filled with regenerative chemicals that flow out when damage occurs. The two liquids mix to form a gel, which spans the gap caused by damage, filling in cracks and holes. Then the gel hardens into a strong polymer, restoring the plastic’s mechanical strength.
“We have to battle a lot of extrinsic factors for regeneration, including gravity,” said study leader White, a professor of aerospace engineering. “The reactive liquids we use form a gel fairly quickly, so that as it’s released it starts to harden immediately. If it didn’t, the liquids would just pour out of the damaged area and you’d essentially bleed out. Because it forms a gel, it supports and retains the fluids. Since it’s not a structural material yet, we can continue the regrowth process by pumping more fluid into the hole.”
The team demonstrated their regenerating system on the two biggest classes of commercial plastics: thermoplastics and thermosets. The researchers can tune the chemical reactions to control the speed of the gel formation or the speed of the hardening, depending on the kind of damage. For example, a bullet impact might cause a radiating series of cracks as well as a central hole, so the gel reaction could be slowed to allow the chemicals to seep into the cracks before hardening.
The researchers envision commercial plastics and polymers with vascular networks filled with regenerative agents ready to be deployed whenever damage occurs, much like biological healing. Their previous work established ease of manufacturing, so now they are working to optimize the regenerative chemical systems for different types of materials.
“For the first time, we’ve shown that you can regenerate lost material in a structural polymer. That’s the kicker here,” White said, “Prior to this work, if you cut off a piece of material, it’s gone. Now we’ve shown that the material can actually regrow.”
Moore, Sottos and White also are affiliated with the Beckman Institute for Advanced Science and Technology at the U. of I. The Air Force Office of Scientific Research supported this work.
The paper, “Restoration of Large Damage Volumes in Polymers,” is available from email@example.com.
Downloadable high-resolution images with cutlines are available.
Liz Ahlberg | University of Illinois
Lowering the Heat Makes New Materials Possible While Saving Energy
26.09.2016 | Penn State Materials Research Institute
Scientists Find Twisting 3-D Raceway for Electrons in Nanoscale Crystal Slices
26.09.2016 | Lawrence Berkeley National Laboratory
Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.
Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...
The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.
“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...
With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.
Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...
For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.
Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...
At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.
In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...
27.09.2016 | Event News
23.09.2016 | Event News
20.09.2016 | Event News
27.09.2016 | Life Sciences
27.09.2016 | Physics and Astronomy
27.09.2016 | Life Sciences