May 28th Swiss researchers have developed a 'nano-valve' that can control the movement of individual particles in the micro-channels at the nanometer scale. It is expected to be used to study the properties of nano-particles and help develop new materials and drugs.
The technology was developed by the research team of the Swiss Federal Institute of Technology in Zurich, Switzerland. They issued a press release saying that the valve is suitable for a variety of particles, such as metal or semiconductor nanoparticles, virus particles, antibody molecules, and can manipulate particles with a diameter of only 10 nanometers. Materials, chemical and biomedical fields are in use.
On the nanometer scale, the properties of matter are very different from those in the macroscopic state, and its movement cannot be controlled by mechanical valves. The researchers etched 300- to 500-nm diameter channels on silicon chips, narrowing the area where valves need to be installed. This 'bottleneck' is mounted on the outside of the electrode. Applying a specific electric field can exert a force on the particles in the channel to determine if it can pass through the bottleneck.
Experiments have shown that nanoparticles in pure water cannot pass through the bottleneck at all times and the valve is closed; applying an electric field allows the particles to pass through the bottleneck, which is equivalent to opening the valve. For the nanoparticles in the saline solution, the situation will be reversed, and the valve is usually open. , Closed after power up.
The researchers used a three-pronged pipe with a valve to allow the two nanoparticles mixed together to flow toward different outlets to achieve separation. This meant that the corresponding piping system and electric field were designed to filter and filter specific particles. They also succeeded. The single particle is guided to the area between the two valves and confined in a narrow space. This reduces the interference of the particles' random motion and facilitates the observation of particle properties.
Relevant papers were published in the new issue of the British "Nature Nanotechnology" magazine.