Nanoknife is a cut above

Researchers at the

(NIST) and the

(CU) have designed a carbon nanotube knife that could work like a wire cheese slicer. The prototype nanoknife could allow scientists to cut and study cells more precisely than they can today.

Biologists typically use conventional diamond or glass knives, which cut frozen cell samples at a large angle, forcing the samples to bend and sometimes later crack. Because carbon nanotubes are extremely strong and slender in diameter, they make ideal materials for thinly cutting precise slivers of cells. In particular, scientists might use the nanoknife to make 3D images of cells and tissues for electron tomography, which requires samples less than 300 nanometres thick.

By manipulating carbon nanotubes inside scanning electron microscopes, scientists have begun crafting a suite of research tools, including nanotweezers, nanobearings and nanooscillators. To design the nanoknife, the NIST and CU scientists welded a carbon nanotube between two electrochemically sharpened tungsten needles. In the resulting prototype, the nanotube stretches between two ends of a tungsten wire loop. The knife resembles a steel wire that cuts a block of cheese.