NANOROBOTS- Amazing Devices

Nanorobotics is the technology of creating machines or robots at or close to the microscopic scale of a nanometre (10-9 metres). More specifically, nanorobotics refers to the still largely hypothetical nanotechnology engineering discipline of designing and building nanorobots. Nanorobots (nanobots, nanoids, nanites or nanonites) would be typically devices ranging in size from 0.1-10 micrometers and constructed of nanoscale or molecular components
A computer-instead of giving you a pill or a shot, the doctor refers you to a special medical team which implants a tiny robot into your bloodstream.
The robot detects the cause of your fever, travels to the appropriate system and provides a dose of medication directly to the infected area.

HOW THEY LOOK LIKE?

The nanobots are made of gold and silver colloid balls, as small as two nanometres.

Nanorobots have design-sensors, molecular sorting rotors, fins and propellers. The depicted blue cones show the sensors 'touching' areas." In fact, these nanorobots can move with six-degrees-of-freedom, i.e., arbitrary translation and rotation fins and propellers. They also have specific sensory capabilities to detect the target regions, obstacles and chemicals relevant for their medical application."
This image describes how nanorobots deliver drugs -- at least in a virtual environment. "The 3D environment contains nanorobots, obstacles, biomolecules and specific medical targets. The medical targets represent organ-inlets, displaced stochastically as target locations or drug delivery points for medical application.

HOW WILL THEY WORK?

There are three main considerations scientists need to focus on when looking at nanorobots moving through the body:
• Navigation

• Power

• How the nanorobot will move through blood vessels.

NANOROBOT NAVIGATION

External navigation systems might use a variety of different methods to pilot the nanorobot to the right location. One of these methods is to use ultrasonic signals to detect the nanorobot's location and direct it to the right destination.
Doctors would beam ultrasonic signals into the patient's body. The signals would either pass through the body, reflect back to the source of the signals, or both.
The nanorobot could emit pulses of ultrasonic signals, which doctors could detect using special equipment with ultrasonic sensors.
Doctors could keep track of the nanorobot's location and maneuver it to the right part of the patient's body.
control
and power nanorobots
using MRI devices like this one.
Using a Magnetic Resonance Imaging (MRI) device, doctors could locate and track a nanorobot by detecting its magnetic field.
Doctors might also track nanorobots by injecting a radioactive dye into the patient's bloodstream.
They would then use a fluoroscope or similar device to detect the radioactive dye as it moves through the circulatory system.
Complex three-dimensional images would indicate where the nanorobot is located.
Alternatively, the nanorobot could emit the radioactive dye, creating a pathway behind it as it moves through the body.
Other methods of detecting the nanorobot include using X-rays, radio waves, microwaves or heat.

POWERING NANOROBOTS

Nanorobots could get power directly from the bloodstream.
A nanorobot with mounted electrodes could form a battery using the electrolytes found in blood.
Another option is to create chemical reactions with blood to burn it for energy. The nanorobot would hold a small supply of chemicals that would become a fuel source when combined with blood.
A nanorobot could use the patient's body heat to create power, but there would need to be a gradient of temperatures to manage it.
Power generation would be a result of the Seebeck effect.
The Seebeck effect occurs when two conductors made of different metals are joined at two points that are kept at two different temperatures. The metal conductors become a thermocouple, meaning that they generate voltage when the junctures are at different temperatures. Since it's difficult to rely on temperature gradients within the body, it's unlikely we'll see many nanorobots use body heat for power.
Another possibility for nanorobot power is to use a nuclear power source.

NANOROBOT LOCOMOTION

Assuming the nanorobot isn't tethered or designed to float passively through the bloodstream, it will need a means of propulsion to get around the body. Because it may have to travel against the flow of blood, the propulsion system has to be relatively strong for its size.
Some scientists are looking at the world of microscopic organisms for inspiration. Paramecium move through their environment using tiny tail-like limbs called cilia.
Nanorobot designers sometimes look at microscopic organisms for propulsion inspiration, like the flagellum on this e-coli cell.
Microrobot, a robot only a few millimeters in length uses small appendages to grip and crawl through blood vessels. The scientists manipulate the arms by creating magnetic fields outside the patient's body.
The magnetic fields cause the robot's arms to vibrate, pushing it further through the blood vessels.
The scientists point out that because all of the energy for the nanorobot comes from an external source, there's no need for an internal power source. They hope the relatively simple design will make it easy to build even smaller robots.

NANOROBOTS IN MEDICAL DIAGNOSIS

 • Treating arteriosclerosis: Arteriosclerosis refers to a condition where plaque builds along the walls of arteries. Nanorobots could conceivably treat the condition by cutting away the plaque, which would then enter the bloodstream.
Nanorobots may treat conditions like arteriosclerosis by physically chipping away the plaque along artery walls.

• Breaking up blood clots: Blood clots can cause complications ranging from muscle death to a stroke. Nanorobots could travel to a clot and break it up. This application is one of the most dangerous uses for nanorobots -- the robot must be able to remove the blockage without losing small pieces in the bloodstream, which could then travel elsewhere in the body and cause more problems. The robot must also be small enough so that it doesn't block the flow of blood itself.

• Fighting cancer: Doctors hope to use nanorobots to treat cancer patients. The robots could either attack tumors directly using lasers, microwaves or ultrasonic signals or they could be part of a chemotherapy treatment, delivering medication directly to the cancer site. Doctors believe that by delivering small but precise doses of medication to the patient, side effects will be minimized without a loss in the medication's effectiveness.

• Helping the body clot: One particular kind of nanorobot is the clottocyte, or artificial platelet. The clottocyte carries a small mesh net that dissolves into a sticky membrane upon contact with blood plasma.

Parasite Removal: Nanorobots could wage micro-war on bacteria and small parasitic organisms inside a patient. It might take several nanorobots working together to destroy all the parasites.

• Gout: Gout is a condition where the kidneys lose the ability to remove waste from the breakdown of fats from the bloodstream. This waste sometimes crystallizes at points near joints like the knees and ankles. People who suffer from gout experience intense pain at these joints. A nanorobot could break up the crystalline structures at the joints, providing relief from the symptoms, though it wouldn't be able to reverse the condition permanently.

• Breaking up kidney stones: Kidney stones can be intensely painful -- the larger the stone the more difficult it is to pass. Doctors break up large kidney stones using ultrasonic frequencies, but it's not always effective. A nanorobot could break up a kidney stones using a small laser.
Nanorobots might carry small ultrasonic signal generators to deliver frequencies directly to kidney stones.

• Cleaning wounds: Nanorobots could help remove debris from wounds, decreasing the likelihood of infection. They would be particularly useful in cases of puncture wounds, where it might be difficult to treat using more conventional methods.