Nanodevices created, capable of moving in a liquid medium in a new way

Tiny nanorobots, development and improvement of which recently has been particularly active, have great potential in medical practice: from the targeted delivery of drugs to disease diagnosis, destruction of blood clots and plaques, and even operations. But the main obstacle to the creation of micro-machines is their ability to move in a liquid medium. Some researchers use for this purpose the laser light and magnetic fields, but scientists from the Institute of Intelligent Systems at the Max Planck (Germany) have proposed several different approaches: the movement under the action of ultrasound and under the influence of chemical substances the body.

Nanodevices created, capable of moving in a liquid medium in a new way

As nanorobotov frame protrudes from a thin-walled silica tube diameter of 220 nanometers. The outer or inner surface of the tube is covered by an enzyme called "urease". Urease is notable in that it splits urea into ammonia and carbon dioxide. Accordingly, falling into a liquid, which contains urea (as in our body it contains virtually all liquids), causes a chemical reaction during which the escaping bubbles of carbon dioxide act as "engine", ejecting the one side of the tube and causing it to move . Experiments have shown that nanotube can accelerate to a speed slightly less than 4 centimeters per hour.

The use of ultrasound for the nanobot movement uses something similar principle is also used for the movement of the gas bubbles, with the only difference being that they are enclosed in a special capsule on the surface of the device. Under the influence of ultrasonic vibrations bubbles begin to alternately expand and contract, exerting pressure on the chamber wall, to which they are attached. The oscillation frequency depends on the size of the bubbles, and the closer it is to its resonant frequency, the more efficient the engine starts. As an experiment, the scientists have made a tiny cube, two opposite faces of which were covered with cameras with bubbles. Picking the desired frequency during the experiment cube forced to rotate in a liquid medium at a speed of 1000 rpm. In addition to the obvious advantages, such nanorobots also have another kind of achievement: they are the smallest robots in the world jet-powered. As the project leader Samuel Sanchez,

"Our previous engine, which is now listed in the Guinness Book of World Records, has three times as large. Thus today most engines nanorobotov chemical cleavage reaction using hydrogen peroxide, which is not very useful to have the substance. Products as urea decomposition in contrast, are natural to the body, and their presence does not cause any side effects. "