A nanoknife is a

carbon nanotube A scanning tunneling microscopy image of a single-walled carbon nanotube Rotating single-walled zigzag carbon nanotube A carbon nanotube (CNT) is a tube made of carbon with diameters typically measured in nanometers. ''Single-wall carbon na ...

-based prototype compression cutting tool intended for sectioning of biological cells. Working principle is similar to that of a 'cheese slicer', a nanometer-thin individual carbon nanotube strung between two tungsten needles would allow sectioning of very thin slices of biological matter for imaging under an

electron microscope An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a hi ...

. Tests are currently being performed by scientists at

Virginia Tech Virginia Tech (formally the Virginia Polytechnic Institute and State University and informally VT, or VPI) is a Public university, public Land-grant college, land-grant research university with its main campus in Blacksburg, Virginia. It also ...

CU-Boulder The University of Colorado Boulder (CU Boulder, CU, or Colorado) is a public research university in Boulder, Colorado. Founded in 1876, five months before Colorado became a state, it is the flagship university of the University of Colorado syst ...

and other universities. A successful development of this new tool will allow scientists and biologists to make 3D images of cells and tissues for electron tomography, which typically requires samples less than ~300 nanometers in thickness. In 2009, the nano-knife was used to create indentation marks on biological cell plasticizer (epoxy resin). The whole cutting process is currently limited by electron charging of

polymer A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...

ic specimen in the SEM, which makes it difficult to observe any small cut or mark as the carbon nanotube is pressed against the specimen. Nanoknife Procedure Doctors use a special medical device designed for the specific purpose of performing

irreversible electroporation Irreversible electroporation is a soft tissue Ablation#Medicine, ablation technique using short but strong Electric field, electrical fields to create permanent and hence lethal nanopores in the cell membrane, to disrupt cellular homeostasis. The ...

. The device implements a direct current generator which emits short pulses of high voltage electric current through electrodes into the cell membrane. The doctor inserts thin needles into the area, using ultrasound imaging to guide the placement of the needles. In nanoknife treatment, strong electric fields cause cells to die without exposing the tissue to radiation or heating it. Most patients don’t feel anything at all during the procedure.

References

Virginia Tech Carbon nanotubes Cell biology Microscopy {{cell-biology-stub