Televisions have changed dramatically: While bulky TV sets dominated our living rooms until just a few years ago, the screens are now so flat that they can easily be hung on the wall.
A close look at the inside of these devices will reveal fine conductor paths and transistors that supply the electricity needed to switch the pixels on the screen on and off. These circuits are manufactured layer by layer, usually by photolithography. The materials are deposited onto the entire surface of a substrate and covered with photoresist, which is exposed to light at specific points using a mask.
The exposed photoresist alters its chemical properties: It becomes soluble and can be easily removed. The layer to be structured returns to the surface and can be etched away. However, the parts of the layer still covered with photoresist remain intact. One major disadvantage of this process is that a large fraction of the deposited material is not used. A more cost-efficient and resource-saving method is to deposit the material by printing only in places where it will actually be needed later.
Printed electronics already exist in the form of conductor paths and devices made from polymers. However, their electrical properties cannot compete with those of inorganic materials. The charge carriers in the polymers travel more slowly, with the result that a printed RFID tag, for example, will have a shorter transmission range than a conventional one. Moreover, polymers tend to react more sensitively to moisture and UV light. Researchers at the Fraunhofer Institute of Integrated Systems and Device Technology IISB in Erlangen have now commissioned a process line in which electron devices can be printed from inorganic materials using an ink jet similar to those in any office printer. “We use ink made of nanoparticles and add a stabilizer so that the particles can be easily processed and do not clump together,” says IISB group manager Dr. Michael Jank.
The nano ink has passed the first printing tests and Jank hopes that the researchers will be able to print circuits performing simple functions in about a year’s time. “We expect printed products to cost around 50 percent less than silicon-based ones in the case of simple circuits,” he says. “Printed RFID tags should then be cheap enough to be attached to the packaging of low-cost products such as yogurts, where they can then monitor the temperature, and store and transmit data.”
Dr.-Ing. Michael Jank | alfa
Producing electricity during flight
20.09.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Solar-to-fuel system recycles CO2 to make ethanol and ethylene
19.09.2017 | DOE/Lawrence Berkeley National Laboratory
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy