Swiss scientists have proposed a simple and scalable method of producing fibers from amorphous metals. A small ribbon of metallic glass coated with a thermoplastic polymer, gradually stretched at high temperatures. As a result, the authors obtained micro – and nanofibers with a length of tens of meters. Materials tested on the example of smart fabrics and biocompatible devices in rats. The results of a study published in the journal Nature Nanotechnology.
Amorphous metals are of particular interest to materials scientists, because the disorder of atoms they possess high strength and toughness, corrosion resistance and high magnetic permeability. In the micro – and nanoscale physical properties of such materials depend on geometrical parameters. The device with the elements of nanostructured materials from amorphous metals would be useful in creating MEMS and biodegradable implants.
Many methods for producing nanostructures from a metallic glass includes the steps of etching or cutting from a large mass of material. Get them directly is difficult, however, Wei Yan (Wei Yan) with colleagues from the Federal Polytechnic school of Lausanne have proposed a simple approach to the creation of micro – and nanofibers from amorphous metals in flexible polymer membranes according to the technology of thermal stretching. Similarly, the establishment of optical fiber, the tape of amorphous metal coated with a thermoplastic polymer, stretched under the action of high temperatures.
Both of the strip material should be plastic at the temperature of extrusion, so the authors chose the materials to create the polyetherimide and fibers of amorphous alloy of platinum, copper, Nickel and phosphorus. When first pulling the metal tape with a thickness of 60 microns was refined to a few microns. Part of this tape was cut off, again wrapped in palifermin and stretched, reducing the thickness to several hundred nanometers. The third extrusion made it possible to obtain fibres with a thickness of several tens of nanometers. The polymer shell can then be easily removed mechanically or dissolved.