Credit: © 2006 IOP

The precise manipulation of tiny objects, such as nanotubes and nanowires, is hampered by their tendency to stick very strongly to surfaces. Controlling the balance of adhesion forces between the object, surface and manipulation tool is difficult. Now, researchers from Denmark and the UK have shown how a forest of vertically aligned multiwalled carbon nanotubes (MWNT) can be used as a non-stick workbench on which objects can be easily moved around.

Kjetil Gjerde and co-workers1 compared how latex microbeads and organic nanofibres adhered to thin films made of either MWNT forests, gold, Teflon or diamond-like carbon. They deflected a cantilever against the beads on the various surfaces and measured the static force. Clusters of beads were most easily released and moved around on the MWNT forest surface.

When lifting nanofibres from the surface using fine tungsten tips, it was found that they could be lifted most easily from the MWNT surface. In addition to the low friction force and small contact area between the fibre and surface, the soft and springy MWNT forest allowed the tip to be pushed under the nanofibre before lifting — a sequence not possible on other substrates.