Various groups of scientists and engineers in recent years made significant progress in the creation of micro-robots , whose dimensions are comparable to the size of living cells and are capable of acting as tiny surgical instruments. However, the small size of these devices determines the number of difficulties associated with their operations management technologies. Most of these microrobots controlled by external magnetic fields, and researchers from the Institute of Intelligent Systems at the Max Planck headed by (Clemens Bechinger), have developed a micro-robots that imitate the way some of the kinds of microorganisms are always moving in the direction of the light source.
Phototaxis (Phototaxis) – is one of the most common types of behavior of animals and plants in the world.One of the clearest examples of phototaxis is moths and mosquitoes, curling around a burning street lamp. However phototaxis can also have the opposite effect – is enough to imagine a scatter in different directions cockroaches when you turn on the light in the room of a cheap motel.
What makes phototaxis is so attractive for robotics – are simple principles of conduct, based on the light intensity. Some of the living beings are attracted to light sources, while others are doing their utmost to avoid them, and others – looking for areas where the lighting is only in strictly defined framework. Using these principles, researchers from Germany created micro-robots that can not only move toward the light source, and removed from it or be mixed in a certain area of space.
In order to realize the above-mentioned simple principles conduct live microorganisms using fairly sophisticated mechanisms. The main role is played by the ability to sense and respond to light with specific characteristics, however, this possibility is almost impossible to implement at the level of microscopic robots. Microrobots do not resemble that of conventional robots, and even bacteria. In fact, they are glass microspheres of a few thousandths of a millimeter in size, one hemisphere of which is covered with a black dye to the carbon black base.
These micro-robots are placed in an aqueous solution of certain organic substances are separated from the water under heat. When the light evenly illuminates the “two-faced” particles, their black side heats up more than the other. The solution near the hot side is split and there are forces of surface tension, trying to restore the balance that the particles move in the direction of the transparent part.
Despite the fact that scientists have managed to make such particles move, they will have to work hard before such a movement will begin to take a strictly orderly. Now when covering micro robots, they are moving in the right direction by one-tenth of a millimeter, and then they begin to “scatter” like cockroaches in different directions. If, however, scientists can create a gradient of the light incident on each microrobot, these micro-robots will move orderly in a direction towards the light source. And if you create a gradient is reversed, the particles will start to rotate in one place.
Now scientists are engaged in the problem of the creation of “light paintings”, containing concentric and parallel regions of low and high intensity. Microrobots exposed to light in such a “picture” will be able to move in a given direction over long distances, than now. In addition, the scientists are planning to add to the microrobot some chemical components that allow them to find cancer cells in the body and release it strictly defined doses of the drugs used for chemotherapy.