LCD as a molecular magnifying glass
Dutch researcher Johan Hoogboom has developed a technique for making LCDs (liquid crystal displays) without the need for cleanrooms. This technique is simpler and cheaper than current methods and is based entirely upon the self-ordering of molecules on a surface. Furthermore, the chemist has shown that these LCDs can be used to make DNA visible to the naked eye.
Hoogboom constructed a surface that can align liquid-crystal molecules. For this he designed and produced an aromatic chemical compound. When this was applied to the surface used for the manufacture of LCDs, the molecules automatically organised themselves into a regular pattern. These surfaces could then align liquid crystals, which is a requirement for the construction of LCDs.
Furthermore, the researcher used these surfaces to produce a new generation of biosensors. Hoogboom demonstrated that the aligned liquid crystals could be used to make the effect of an enzyme or the presence of certain types of DNA visible, without the need for extra equipment. This opens up the way for a new generation of biosensors, which can analyse materials on the spot.
An LCD consists of two polarisation filters, placed at 90 degrees to each other. The liquid crystals are oriented parallel to the direction of their respective polariser, which causes them to adopt a helical shape inside the display. Light that passes through one filter, travels through the helix, changes its direction of polarisation by 90 degrees and can then leave through the second filter on the other side. If a voltage is placed across the display, the helical shape is lost. Light that enters on one side, then no longer changes in polarisation direction and can no longer pass through the second filter, making it appear dark.
To make an LCD, it must be possible to align the liquid crystals in a single direction, so that they are positioned parallel to the direction of both polarisation filters. The present production technique is based on a principle that has already been known for 100 years. In this technique, the aligning surfaces are made in a cleanroom by rubbing a velvet cloth in the right direction over thin polymer layers. Due to the increasing demand for larger and better displays, this method is reaching its technical limits. Further-more, the method is extremely labour intensive and highly sensitive for environmental factors, such as dust.
Johan Hoogboom has received a Talent grant from NWO with which he will take up a post-doc position at MIT in Cambridge (US) in January 2005.
The research was funded by Technology Foundation STW.
Drs Johan Hoogboom | alfa
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...