The Ashes

Researchers have developed world’s first nanofluidic device with complex 3D surfaces which could have enormous implications in applications like nanoscale materials processing, in pharmaceuticals, nanoparticles sorting, and it could help isolating particular DNA strands for further research studies.

The scientists from the National Institute of Standards and Technology were inspired by the manufacturing process of integrated circuits and they used it at nanoscale. The result is world’s first nanofluidic device with 3D complex surfaces called the “Lilliputian chamber” which will be used with custom-based surfaces to engineer nanoparticles among many other applications. In order to develop a nanofluidic device, researchers have to etch very small channels into a silicon wafer, just like in the manufacturing process of an integrated circuit.

So far, researchers have only managed to develop simple surfaces of only a few depths meaning that you cannot study DNA or other molecules in detail. Now, that their ability is not limited anymore, researchers will be able to study complex surfaces of nanoparticles in detail.  The manufacturing process of integrated circuits is based on “lithographic” procedures, and the researchers used them to develop complex 3D surfaces, then they designed a nanofluidic chamber which featured a staircase geometry engraved in its floor. The steps of the staircase represented a level, each increasing in depth from 10 nanometers to 620 nanometers.

In order to test their Lilliputian chamber with 3D complex surfaces, the researchers used two solutions/materials – first was based on 100-nanometer in diameter of polystyrene spheres, while the latter consisted of 20-micrometer in length DNA molecules. In the tests, the researchers introduced the solution in the deep end of the chamber, then they maneuvered the samples across the chamber using electric fields, and they tracked their movements on a microscope (the polystyrene spheres, and the DNA strands were “tagged” with fluorescent dyes to observe their movement).

The results of the tests were very convincing as when using polystyrene spheres, the so-called “size exclusion” happened when the area of the Lilliputian chamber (the channels were less than 100-nanometers in depth) remained free of the nanoparticles. When using the DNA strands, the molecules were coiled in much deeper channels, and then forced to enter in shallower channels. In other words the results clearly show that NIST’s nanofluidic device can be used to perform complex 3D operations at nanoscale.

The Lilliputian chamber could have enormous implications in various applications like scientific studies, safety invetigations, and for environmental health. The research if only at the beginning, and now the NIST researchers are looking to separate mixtures of nanoparticles, and to study DNA’s behavior in a 3D nanofluidic device.