Based on the rapid evaporation of solvent from simple “inks,” the process has been used to fabricate freestanding nanofibers, stacked arrays of nanofibers and continuously wound spools of nanowires. Potential applications include electronic interconnects, biocompatible scaffolds and nanofluidic networks.
“The process is like drawing with a fountain pen – the ink comes out and quickly dries or ‘solidifies,’ ” said Min-Feng Yu, a professor of mechanical science and engineering, and an affiliate of the Beckman Institute. “But, unlike drawing with a fountain pen, we can draw objects in three dimensions.”
Yu and graduate students Abhijit Suryavanshi and Jie Hu describe the drawing process in a paper accepted for publication in the journal Advanced Materials, and posted on its Web site.
To use the new process, the researchers begin with a reservoir of ink connected to a glass micropipette that has an aperture as small as 100 nanometers. The micropipette is brought close to a substrate until a liquid meniscus forms between the two. As the micropipette is then smoothly pulled away, ink is drawn from the reservoir. Within the tiny meniscus, the solute nucleates and precipitates as the solvent quickly evaporates.
So far, the scientists have fabricated freestanding nanofibers approximately 25 nanometers in diameter and 20 microns long, and straight nanofibers approximately 100 nanometers in diameter and 16 millimeters long (limited only by the travel range of the device that moves the micropipette).
To draw longer nanowires, the researchers developed a precision spinning process that simultaneously draws and winds a nanofiber on a spool that is millimeters in diameter. Using this technique, Yu and his students wound a coil of microfiber. The microfiber was approximately 850 nanometers in diameter and 40 centimeters long.
To further demonstrate the versatility of the drawing process, for which the U. of I. has applied for a patent, the researchers drew nanofibers out of sugar, out of potassium hydroxide (a major industrial chemical) and out of densely packed quantum dots. While the nanofibers are currently fabricated from water-based inks, the process is readily extendable to inks made with volatile organic solvents, Yu said.
“Our procedure offers an economically viable alternative for the direct-write manufacture of nanofibers made from many materials,” Yu said. “In addition, the process can be used to integrate nanoscale and microscale components.”
The Grainger Foundation, the National Science Foundation and the Office of Naval Research provided funding. Part of the work was carried out in the university’s Center for Microanalysis of Materials, which is partially supported by the U.S. Department of Energy.
To reach Min-Feng Yu, call 217-333-9246; e-mail: email@example.com.
James E. Kloeppel | University of Illinois
Blue phosphorus -- mapped and measured for the first time
16.10.2018 | Helmholtz-Zentrum Berlin für Materialien und Energie
All in the family: Kin of gravitational wave source discovered
16.10.2018 | University of Maryland
Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz (Germany) together with scientists from Dresden, Leipzig, Sofia (Bulgaria) and Madrid (Spain) have now developed and characterized a novel, metal-organic material which displays electrical properties mimicking those of highly crystalline silicon. The material which can easily be fabricated at room temperature could serve as a replacement for expensive conventional inorganic materials used in optoelectronics.
Silicon, a so called semiconductor, is currently widely employed for the development of components such as solar cells, LEDs or computer chips. High purity...
Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles
Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...
When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.
We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...
Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...
Das Zusammenspiel aus Struktur und Dynamik bestimmt die Funktion von Proteinen, den molekularen Werkzeugen der Zelle. Durch Fortschritte in der...
17.10.2018 | Event News
16.10.2018 | Event News
02.10.2018 | Event News
17.10.2018 | Trade Fair News
17.10.2018 | Life Sciences
17.10.2018 | Agricultural and Forestry Science