Nanobrain for nanorobots
Anirban Bandyopadhyay and Somobrata Acharya from the International Center for Young Scientists (ICYS) in Tsukuba (Japan) created a complex molecular structure that served as a command device for several nanorobots.
In their experience, the researchers have shown in practice that a system assembled from 17 DRQ molecules (2,3,5,6-tetramethyl-1-4- benzoquinone), can work as a processor that executes 16 instructions in one clock cycle.
One such molecule is similar in shape to a ring with four spokes, which can individually occupy several different positions (which can be interpreted as binary zeros and ones). 16 DRQ molecules also make up a ring, with the 17th "sister" in the center, and together form a molecular machine capable of encoding over 4 billion combinations in the position of its parts.
It is important that the switching of states of all 16 molecules in the outer ring is managed by only one, the same central molecule (all 17 DRQ are connected by hydrogen bonds). Well, physicists can arbitrarily change the state of this molecule using a scanning tunneling microscope.
The authors of the invention compare the principle of its operation with the communication system of cells in the human brain, as well as with the processor. "We 'instruct' just one molecule," says Bandiopadhyay, "and thus simultaneously perform a logical switching of 16 molecules."
But why is it necessary? Scientists and doctors pin great hopes on the healing of patients with the help of hypothetical (so far) nanorobots capable of delivering drugs to a strictly set goal or performing some "meaningful" actions in the blood stream. But one of the key issues here is the management of such tiny molecular machines. Simply put, nanobots need "nanobrains".
The molecular structure with a diameter of only two nanometers, built by Bandiopadhyay and Acharya, is the first sample of such a "nanobrain" in the world. It may not be very complicated yet, but it works.
The researchers set up such an experiment: they fixed eight nanomachines on the outside of their "brain". These were several different molecular complexes, including, for example, the world's smallest elevator – a molecular platform that, on command, could rise and fall to a height of less than one nanometer (the diameter of the platform was 2.5 nanometers).
Under the "eye" of the tunneling microscope, all eight nanobots followed the instructions given by scientists through a single central DRQ molecule, that is, they performed some predetermined movements.
This complex of molecules Bandiopadhyay and Acharya called "chemical Swiss army knife".
And although the need to use a tunneling microscope to give commands negates all the phenomenal miniaturization of the system, this experience shows the way, having followed it to the end, scientists will probably be able to build molecular robots capable of complex programmed actions inside the body and, moreover, inside individual cells.
And, according to the authors of the work, their "chemical brain" can become the basis for super-productive processors designed not for molecular machines, but for computers. The creators of the "molecular processor" built a larger version of it, capable of performing 256 operations in one switch, and developed a modification for 1024 operations.
The article by Anirban Bandyopadhyay and Somobrata Acharya A 16-bit parallel processing in a molecular assembly is published in PNAS.
Portal "Eternal youth" www.vechnayamolodost.ru
13.03.2008