nano particle capturing by nano gap device

A Korean research team has developed a technology that enables the effective control of fine particulate matter and nanoplastics, which are major causes of human toxicity and ecosystem disturbances. This technology, which allows for real-time sorting, purification, and concentration of nanoparticles invisible to the human eye has great potential application, not only for the removal of toxic particles from the natural environment, but also for removing viruses and detecting dementia-related proteins and cancer diagnostic markers. 

announced the development of a nanogap electrode able to capture ultra-fine floating particles as small as 20 nanometers 

Researchers around the world are pursuing techniques to manipulate nano-size particles without damaging them. The optical tweezers technology, which received the Nobel Prize in Physics in 2018, is representative of such technologies. However, it has proven difficult to go beyond individual particle-level manipulation/measurement and to realize commercialization on a massive scale. Researchers have repeatedly run into technical limitations in scaling mechanisms for collecting, sorting, purifying and concentrating particles that are 100 nm or less in size; however, such mechanisms are needed to work in large-scale atmospheric and water environments.

successfully scaled up the nanogap electrodes by sandwiching nanoscaled insulator film between two electrodes in a vertical alignment, allowing the dielectrophoretic tweezer technology to be applied to large areas. Dielectrophoresis is a technology wherein wavelengths vibrating several hundred to several thousand times per second are applied to two electrodes to form a non-uniform electrical field distribution around the electrodes. The electrodes are then used to attract or repel particles in the vicinity of the nanogaps.

he team found that the dielectrophoretic force produced by electrodes in an asymmetric electrode-arranged vertical array was over 10 times greater than that of a conventional horizontally aligned nanogap array.

According to the research team, when used in air or water filters, the nanogap electrodes can function under low voltage (such as that of an ordinary AA cell) to detect and remove, in real time, various microscopic floating particles such as fine dust, nanoplastics, viruses, germs, and bacteria.

 

reference

 Eui-Sang Yu et al, Precise capture and dynamic relocation of nanoparticulate biomolecules through dielectrophoretic enhancement by vertical nanogap architectures, Nature Communications (2020). DOI: 10.1038/s41467-020-16630-w