New Jersey Institute of Technology (NJIT) research professors, Zafer Iqbal and Reginald C. Farrow have received a US patent 7,964,143 for their innovative method of producing arrays of nano-sized electrical probes.
The new findings could enhance diagnostic metrology instruments used to measure the electrical activity’s spatial variation in biological cells. The patent covers a nanoprobe array technology that utilizes electrophoresis to assemble an array of vertically oriented, single carbon nanotubes at accurate spots on electrical contacts.
A nano-sized electrostatic lens produced by a method commonly utilized in the production of integrated circuits controls the position of every nanotube in the arrangement. The lens geometry controls the number of nanotubes placed at each spot allowing deposition of each nanotube in a pane much bigger than its diameter.
Subsequent to the deposition, each carbon nanotube can be altered to insulate the shaft and make it sensitive to a particular ion in the cell. The job is completed by fixing a suitable functional enzyme or molecule to the nanotube’s tip. The nanoprobe array can be setup for numerous electrochemical processes to be charted on timescales, which are restricted only by the nature of the contact of the nanotubes with the cell membrane and the integrated circuits’ speed.
The US patent 7,964,143 and its companion patent 7,736,979 awarded in 2010 describe a process for single carbon nanotube deposition vertically in an electronic circuit utilizing technologies currently employed in the production of computer chips. This method allows the connection of biological sensing with electronic technology at the nanoscale.
By utilizing electrophoresis, the carbon nanotubes present in a liquid suspension are directed to metal contacts at the bottom of accurately positioned via. Every via gets charged and mimics like an electrostatic lens. After the deposition of the first nanotube, the electric field is altered, resulting in the redirection of other nanotubes from deposition on the metal even though the via has a diameter many times larger than the nanotube element diameter. This innovation paves the way to the patent-pending and patented techniques, including the nanoprobe array, a planar biofuel cell and a vertical transistor utilizing an individual 1-nm carbon nanotube.
Source: http://www.njit.edu