This will significantly advance our ability to fabricate advanced functional surfaces
- Michael de Volder
These surfaces, made by self-organisation of carbon nanotubes, could exhibit a variety of useful properties — including controllable mechanical stiffness and strength, or the ability to repel water in a certain direction.
The technique works by inducing carbon nanotubes – extremely thin, hollow cylinders of carbon atoms - to bend as they grow. The mechanism is analogous to the bending of a bimetallic strip, used as the control in old thermostats, as it warms: one material expands faster than another bonded to it. But in this new process, the material bends as it is produced by a chemical reaction.
The process begins by depositing two patterns onto a substrate: one is a catalyst of carbon nanotubes; the second modifies the growth rate of the nanotubes. By offsetting the two patterns, the researchers showed that the nanotubes bend into predictable shapes as they extend. Details of the new technique were recently published in the journal Nature Communications.
The team were able to specify these simple two-dimensional instructions, and cause the nanotubes to form complex shapes in three dimensions. Where nanotubes growing at different rates are adjacent, they push and pull on each other, producing more complex forms.
“This process enables an unprecedented ability to fabricate well-controlled 3D microstructures in high volumes. This will significantly advance our ability to fabricate advanced functional surfaces,” said Dr Michael de Volder of the Institute of Manufacturing at the University of Cambridge, who led the research.
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Image: Complex shapes of carbon nanotubes
Credit: Michael de Volder
Reproduced courtesy of the University of Cambridge
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