The device has 56 separation channels with a length of 4cm, a width of 50-150µm, and a depth of 5-18µm. The channels are packed with vertical micro-cylinders. These pillars are 1-5µm thick, and are separated by gaps of 1-0.1µm. Within one channel, all pillars have an identical shape, size, and distance. The chromatograph was implemented on a 200mm Si wafer.
First, a Si oxide layer was deposited on the wafer, on which the submicron structures of the chromatograph were patterned and etched. Next, with the Si oxide layer as hard mask, the separation channels and the pillars were etched with deep reactive ion etching (DRIE). The separation channels were then connected via wider interconnecting supply channels. A 200mm glass wafer was bonded to the Si wafer, serving as a roof to close off the open separation channels. And last, access holes were etched through the back of the Si wafer.
A comparison with commercial chromatographs with macroscopic tubes shows that the micro-chromatograph is 5 to 10 times as fast, and has a better separation capacity. Also, unlike with macro-chromatographs, the separation does not degrade with higher velocities of molecule transport. The performance of the chromatograph was tested by injecting a fluid with tracer molecules in the chromatograph and following the velocity and width of the resulting tracer band.
Liquid phase chromatography is a powerful technique to separate and identify molecules. It is used, for example, in biochemistry labs to separate proteins. The molecules, suspended in a liquid, are separated by forcing them through macroscopic columns filled with micron-sized, randomly packed spherical particles. This sub-micro chromatograph validates fluid dynamic computations that predict that injecting molecules though a submicron maze of perfectly ordered structures will considerably increase the separation speed of liquid phase chromatography.
Katrien Marent | alfa
SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University
Molecule flash mob
19.01.2017 | Technische Universität Wien
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences