“We’re optimistic that this new approach could lead to large-scale production of stretchable conductors, which would then expedite research and development of elastic electronic devices,” says Dr. Yong Zhu, an assistant professor of mechanical and aerospace engineering at NC State, and lead author of a paper describing the new technique.
The buckled nanotubes look like squiggly lines on a flat surface.
To develop these stretchable electronics, one needs to create conductors that are elastic and will reliably transmit electric signals regardless of whether they are being stretched.
One way of making conductive materials more elastic is to “buckle” them. Zhu’s new method buckles carbon nanotubes on the plane of the substrate. Think of the nanotubes as forming squiggly lines on a piece of paper, rather than an accordion shape that zigs up and down with only the bottom parts touching the sheet of paper. Zhu’s team used carbon nanotubes because they are sturdy, stable, excellent conductors and can be aligned into ribbons.
The new process begins by placing aligned carbon nanotubes on an elastic substrate using a transfer printing process. The substrate is then stretched, which separates the nanotubes while maintaining their parallel alignment.
Strikingly, when the substrate is relaxed, the nanotubes do not return to their original positions. Instead, the nanotubes buckle – creating what looks like a collection of parallel squiggly lines on a flat surface.
The carbon nanotubes are now elastic – they can be stretched – but they have retained their electrical properties.
The key benefit of this new method is that it will make manufacturing of elastic conductors significantly more efficient, because the carbon nanotubes can be applied before the substrate is stretched. This is compatible with existing manufacturing processes. “For example, roll-to-roll printing techniques could be adapted to take advantage of our new method,” Zhu says.
A paper describing the new approach, “Buckling of Aligned Carbon Nanotubes as Stretchable Conductors: A New Manufacturing Strategy,” was published online Jan. 23 in Advanced Materials. The paper was co-authored by Feng Xu, a Ph.D. student at NC State. The research was funded by the National Science Foundation.
In another new paper, Zhu’s team has demonstrated for the first time that carbon nanotubes can be buckled using a technique in which the elastic substrate is stretched before the nanotubes are applied. The substrate is then relaxed, forcing the nanotubes to buckle out of plane. The nanotubes form a ribbon that curves up and down like the bellows of an accordion. This second technique has been used before with other materials. This second paper, “Wavy Ribbons of Carbon Nanotubes for Stretchable Conductors,” was published Jan. 19 in Advanced Functional Materials.
High entropy alloys hold the key to studying dislocation avalanches in metals
16.10.2018 | University of Illinois College of Engineering
Exploring the deep sea – first-time LIBS measurement at 600 bar
16.10.2018 | Laser Zentrum Hannover e.V.
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...
New measurement method allows researchers to precisely follow the movement of individual molecules over long periods of time
The function of proteins – the molecular tools of the cell – is governed by the interplay of their structure and dynamics. Advances in electron microscopy have...
16.10.2018 | Event News
02.10.2018 | Event News
01.10.2018 | Event News
16.10.2018 | Life Sciences
16.10.2018 | Physics and Astronomy
16.10.2018 | Event News