Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fabricated microvascular networks could create compact fluidic factories

24.03.2003


Using direct-write assembly of organic ink, researchers at the University of Illinois at Urbana-Champaign have developed a technique for fabricating three-dimensional microvascular networks. These tiny networks could function as compact fluidic factories in miniature sensors, chemical reactors, or computers used in applications from biomedicine to information technology.



"The fabrication technique produces a pervasive network of interconnected cylindrical channels, which can range from 10 to 300 microns in diameter," said Jennifer Lewis, a professor of materials science and engineering and of chemical engineering at Illinois. "Our approach opens up new avenues for device design that are currently inaccessible by conventional lithographic methods."

The microvascular networks also could be combined with self-healing functionality, "providing an analog to the human circulatory system for the next generation of autonomous healing materials," said Scott White, a professor of aeronautical and astronautical engineering and a researcher at the Beckman Institute for Advanced Science and Technology. "The embedded network would serve as a circulatory system for the continuous transport of repair chemicals to sites of damage within the material."


The scientists report their findings in a paper that has been accepted for publication in the journal Nature Materials, and posted on its Web site www.nature.com/materials.

To create a microvascular network, Lewis, White and graduate student Daniel Therriault begin by fabricating a scaffold using a robotic deposition apparatus and a fugitive organic ink. A computer-controlled robot squeezes the ink out of a syringe, almost like a cake decorator, building the scaffold layer by layer.

"The ink exits the nozzle as a continuous, rod-like filament that is deposited onto a moving platform, yielding a two-dimensional pattern," Lewis said. "After a layer is generated, the stage is raised and rotated, and another layer is deposited. This process is repeated until the desired structure is produced."

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

In the final step, the open network is filled with a photocurable resin. "The structure is then selectively masked and polymerized with ultraviolet light to plug selected channels," Lewis said. "Lastly, the uncured resin is drained, leaving the desired pathways in the completed network."

To demonstrate the effectiveness of their fabrication technique, the researchers built square spiral mixing towers within their microvascular networks. Each of the integrated tower arrays was made from a 16-layer scaffold. The mixing efficiency of these stair-cased towers was characterized by monitoring the mixing of two dyed fluid streams using fluorescent microscopy.

"Due to their complex architecture, these three-dimensional towers dramatically improve fluid mixing compared to simple one- and two-dimensional channels," White said. "By forcing the fluids to make right-angle turns as they wind their way up the tower, the fluid interface is made to fold on top of itself repeatedly. This chaotic advection, in addition to normal diffusion, causes the fluids to become well-mixed in a short linear distance."

In addition to serving as highly efficient and space-saving mixers in microfluidic devices, the microvascular networks offer improved functionality in the design of self-healing materials.

"With our current approach, we distribute microcapsules of healing agent throughout the material," White said. "Where damage occurs locally, the capsules break open and repair the material. With repeated damage in the same location, however, the supply of healing agent may become exhausted."

Using capillaries instead of capsules to carry the healing agent could improve the performance of self-healing materials, White said. "By incorporating a microvascular network within the material, we could continuously transport an unlimited supply of healing agent, significantly extending the lifetime of the material."

James E. Kloeppel | EurekAlert!
Further information:
http://www.nsf.gov/od/lpa/news/03/pr0330.htm

More articles from Process Engineering:

nachricht ScanCut project completed: laser cutting enables more intricate plug connector designs
06.08.2020 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Analyzing pros and cons of two composite manufacturing methods
04.08.2020 | University of Illinois Grainger College of Engineering

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: ScanCut project completed: laser cutting enables more intricate plug connector designs

Scientists at the Fraunhofer Institute for Laser Technology ILT have come up with a striking new addition to contact stamping technologies in the ERDF research project ScanCut. In collaboration with industry partners from North Rhine-Westphalia, the Aachen-based team of researchers developed a hybrid manufacturing process for the laser cutting of thin-walled metal strips. This new process makes it possible to fabricate even the tiniest details of contact parts in an eco-friendly, high-precision and efficient manner.

Plug connectors are tiny and, at first glance, unremarkable – yet modern vehicles would be unable to function without them. Several thousand plug connectors...

Im Focus: New Strategy Against Osteoporosis

An international research team has found a new approach that may be able to reduce bone loss in osteoporosis and maintain bone health.

Osteoporosis is the most common age-related bone disease which affects hundreds of millions of individuals worldwide. It is estimated that one in three women...

Im Focus: AI & single-cell genomics

New software predicts cell fate

Traditional single-cell sequencing methods help to reveal insights about cellular differences and functions - but they do this with static snapshots only...

Im Focus: TU Graz Researchers synthesize nanoparticles tailored for special applications

“Core-shell” clusters pave the way for new efficient nanomaterials that make catalysts, magnetic and laser sensors or measuring devices for detecting electromagnetic radiation more efficient.

Whether in innovative high-tech materials, more powerful computer chips, pharmaceuticals or in the field of renewable energies, nanoparticles – smallest...

Im Focus: Tailored light inspired by nature

An international research team with Prof. Cornelia Denz from the Institute of Applied Physics at the University of Münster develop for the first time light fields using caustics that do not change during propagation. With the new method, the physicists cleverly exploit light structures that can be seen in rainbows or when light is transmitted through drinking glasses.

Modern applications as high resolution microsopy or micro- or nanoscale material processing require customized laser beams that do not change during...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“Conference on Laser Polishing – LaP 2020”: The final touches for surfaces

23.07.2020 | Event News

Conference radar for cybersecurity

21.07.2020 | Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

 
Latest News

Rare Earth Elements in Norwegian Fjords?

06.08.2020 | Earth Sciences

Anode material for safe batteries with a long cycle life

06.08.2020 | Power and Electrical Engineering

Turning carbon dioxide into liquid fuel

06.08.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>