Nano-Robot Technology: Medical Perspective
A nanorobot is a tiny machine designed to perform a specific task or tasks repeatedly and with precision at nanoscale dimensions, that is, dimensions of a few nanometers (nm) or less, where 1 nm = 10^-9 meter. Nanorobots have potential applications in the assembly and maintenance of sophisticated systems. Nanorobots might function at the atomic or molecular level to build devices, machines, or circuits, a process known as molecular manufacturing. Nanorobots might also produce copies of themselves to replace worn-out units, a process called self-replication.
Nanorobots are of special interest to researchers in the medical industry. This has given rise to the field of nanomedicine. It has been suggested that a fleet of nanorobots might serve as antibodies or antiviral agents in patients with compromised immune systems, or in diseases that do not respond to more conventional measures. There are numerous other potential medical applications, including repair of damaged tissue, unblocking of arteries affected by plaques, and perhaps the construction of complete replacement body organs.
A major advantage of nanorobots is thought to be their durability. In theory, they can remain operational for years, decades, or centuries.The first generation of nanorobots will likely fulfill very simple tasks, becoming more sophisticated as the science progresses. They will be controlled not only through limited design functionality but also through programming and the aforementioned acoustic signaling, which can be used, notably, to turn the nanorobots off.
Robert A. Freitas Jr., author of Nanomedicine, gives us an example of one type of medical nanorobot he has designed that would act as a red blood cell. It consists of carbon atoms in a diamond pattern to create what is basically a tiny, spherical pressurized tank, with "molecular sorting rotors" covering just over one-third of the surface. To make a rough analogy, these molecules would act like the paddles on a riverboat grabbing oxygen (O2) and carbon dioxide (CO2) molecules, which they would then pass into the inner structure of the nanorobot.
The entire nanorobot which Freitas dubbed a respirocyte, consists of 18-billion atoms and can hold up to 9-billion O2 and CO2 molecules, or just over 235 times the capacity of a human red blood cell. This increased capacity is made possible because of the diamond structure supports greater pressures than a human cell. Sensors on the nanorobot would trigger the molecular rotors to either release gasses, or collect them, depending on the needs of the surrounding tissues. A healthy dose of these nanorobots injected into a patient in solution, Freitas explains, would allow someone to comfortably sit underwater near the drain of the backyard pool for nearly four hours, or run at full speed for 15 minutes before taking a breath.
Up to this point in time, the closest thing to a purely mechanical nanorobot that has ever been created was the work of U.C. Berkeley affiliate Kris Pister. He invented a solar-powered robot that measures only 8.5 millimeters and can walk slowly on two “legs” like humans do. True to form, Pister composed his robot primarily of tiny silicon pieces called transducers which are capable of taking the energy generated by the robot’s solar cell and turning it into mechanical power. Although extremely tiny, technically the robot that Pister created is macroscopic. But it does represent a valuable step in the scaling-down process of traditional electromechanical robots.
An upcoming event is that, a tiny device a quarter of a millimeter in diameter would be able to trace the blood in an artery to an area to operate and use miniature instruments, controlled remotely by a surgeon. For now, the nanochirurgien able to slip into an artery does not exist yet. But an Australian team at Monash University, headed by James Friend, had described a prototype in the Journal of Micromechanics and Microengeenering.
This tiny device includes a helical rod of 250 microns
in diameter, a quarter of a millimeter, which can be rotated with a very
low current. Stator called, it begins to run under the effect of a piezoelectric
element. Commonly used, such material – a crystal – a property to come into
effect under the vibration of an electric current, or, conversely generate
a flow at the slightest shock. The lighter gases are an example of applications,
as well as engines of electronic watches and reading heads of some turntable
too ancient.
The prototype is given below. . The stem is helically grooved stator and
measures a little over 1 mm in height to 250 microns in diameter. It can
turn on itself and has a viewing sphere rotation. All depends on the piezoelectric
element.
The prototype has demonstrated the feasibility of such an engine in the required dimensions for insertion into an artery. Because in the long line of assistance to robotic surgery, it is the destiny of this device. Its designers have also called Proteus, named after the submarine microscopic imagined by Isaac Asimov’s new Fantastic Voyage, taken to the cinema in a movie together. It shows a crew miniaturized human but also introduced with the submersible in the body of a man to go destroy a blood clot in the brain which will effectively use in brain cancer.
Such a mission could one day be entrusted to a machine as Proteus. With a rotation of 1295 revolutions per minute, miniature robot that could, say the researchers traced the flow of blood if it is not too powerful, for example in the brain, but not near the heart where the gear would be taken away.