NEWS
25.11.2020

German Centre for Mathematics Teacher Education (DZLM) will be sustained

The German Centre for Mathematics Teacher Education (DZLM) will be a part of the newly established department “Subject-related knowledge transfer” at the Leibniz Institute for Science and Mathematics Education (IPN) in Kiel. The DZLM is a network of nine universities under the direction of the Humboldt-Universität zu Berlin. For ten years it has been developing, implementing and researching nationwide effective offers for further education for multipliers, teachers and daycare specialists in mathematics. The DZLM was initiated by the Deutsche Telekom Stiftung, from which it has so far been financed with more than ten million euros.

"The work of the DZLM has shown that advanced trainers need far more skills than just being very good teachers in their subjects," explains the previous director of the DZLM and future director of the new IPN department, Professor Jürg Kramer, who is also a member of IRIS Adlershof. “Our approach is therefore to qualify further trainers not only in terms of further training methodology and adult pedagogy, but also very specifically on subject-specific questions relating to the content and learning processes of teachers in further training. In this way, they are much better able to support teachers and educational specialists effectively in their daily work. We are very pleased that we can now continue this work at the IPN "

IRIS Adlershof warmly congratulates and looks forward to continued good cooperation.

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18.11.2020

Berlin becomes a center for national high-performance computing

The Joint Science Conference of the federal and state governments (GWK) is establishing a total of eight centers for “National High-Performance Computing” (HPC), one of them in Berlin. To this end, the Zuse-Institute Berlin (ZIB) was approved for funding as the centre for scientific computing of the Berlin University Alliance (BUA), the cluster of excellence comprising of the three major universities Freie Universität Berlin, Humboldt-Universität zu Berlin, Technische Universität Berlin as well as the Charité – University Hospital Berlin. Prof. Alexander Reinefeld, scientific director at the Zuse-Institute and member of IRIS Adlershof delightedly says: „The funding to the tune of approximately 72 million euros affords the Zuse-Institute planning security for the acquisition, modernisation and operation of HPC systems for the next ten years, of which the university research, in particular in Berlin and therefore at IRIS Adlershof, will surely profit.“ He adds, „that the financial support provided by the state of Berlin and the Federation will also be used to provide expert counseling to make the efficient usage of the complex supercomputers easier for the scientists.“

IRIS Adlershof cordially congratulates and is looking forward to continued fruitful collaboration.

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18.11.2020

Joachim Sauer receives Bunsen-Denkmünze 2020

The German Bunsen-Society for Physical Chemistry honours Joachim Sauer, professor at Humboldt-Universität zu Berlin as well as former and founding member of  IRIS Adlershof, in recognition of his seminal work. The Bunsen-Denkmünze has been awarded since 1908 to "personalities who advanced the goals of physical chemistry through scientific or practical achievments in an extraordinary way".

IRIS Adlershof cordially congratulates Prof. Sauer.


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13.11.2020

Implementation of Flexible Embedded Nanowire Electrodes in Organic Light‐Emitting Diodes

Researchers in the HySPRINT joint lab Generative manufacturing processes for hybrid components (GenFab) of Humboldt-Universität zu Berlin (HU) and Helmholtz-Zentrum Berlin (HZB) have developed together with the Austrian Institute of Technology (AIT) a method to produce flexible transparent electrodes based on silver nanowires. Specifically, the nanowires are spray coated and embedded within a polymer resin on top of polyethylene terephthalate (PET) substrate.

Not only are the electrodes fabricated using solution-based approaches, but compared with the widely used indium tin oxide (ITO), the electrodes show higher stability in mechanical bending tests. "Since the spray coating approach in this work can be upscaled to larger areas", says Dr. Felix Hermerschmidt, senior researcher in the joint lab of HU and HZB, "this mechanical stability can be translated to an industrial process."

The researchers fabricated organic light-emitting diodes employing the developed ITO‐free nanowire electrodes. These show considerably higher luminance values at the same efficacy compared to their ITO‐based counterparts. As Dr. Theodoros Dimopoulos, senior scientist at AIT, points out, "Replacing ITO in optoelectronic devices is a key area of research and this work shows the possibilities of doing so without loss in performance."

GenFab, led by IRIS Adlershof member Prof. List-Kratochvil, is moving in laboratory rooms in the new IRIS-research building for further development.

The work has been published in physica status solidi rapid research letters and is featured on the cover of the November 2020 issue of the journal.


Publication
Lukas Kinner, Felix Hermerschmidt, Theodoros Dimopoulos, and Emil J. W. List-Kratochvil
Implementation of Flexible Embedded Nanowire Electrodes in Organic Light‐Emitting Diodes
Phys. Status Solidi RRL 14 (2020) 2000305
 

20.10.2020

The future of bio-medicine?

Researchers from Humboldt University and the Experimental and Clinical Research Center (ECRC) built the first infrared based microscope with quantum light. By deliberately entangling the photons, they succeeded in imaging tissue samples with previously invisible bio-features.

Researchers of the  Emmy Noether Junior Research Group "Nonlinear Quantum Optics" of the physics department and IRIS Adlershof of Humboldt-Universität zu Berlin and of the Experimental and Clinical Research Center (ECRC), a joined institution from Charité – Universitätsmedizin Berlin and Max Delbruck Center for Molecular Medicine in the Helmholtz Association, are featured on the cover of ‘Science Advances’ with their new experiment. For the first time they successfully used entangled light (photons) for microscope images. This very surprising method for quantum imaging with undetected photons was only discovered in 2014 in the group of the famous quantum physicist Anton Zeilinger in Vienna. The first images show tissue samples from a mouse heart.

The team uses entangled photons to image a bio-sample probed by ‘invisible’ light without ever looking at that light. The researchers only use a normal laser and commercial CMOS camera. This makes their MIR microscopy technique not only robust, fast and low noise, but also cost-effective - making it highly promising for real-world applications. This use of quantum light could support the field of biomedical microscopy in the future.

Quantum microscopy of a mouse heart. Entangled photons allow for the making of a high-resolution mid-IR image, using a visible light (CMOS) camera and ultralow illumination intensities. In the picture, absorption (left) and phase information (right) from a region in a mouse heart. The yellow scale bar corresponds to 0.1 mm which is about the width of a human hair.

Current camera detection is unequivocally dominated by silicon based technologies. There are billions of CCD (charge coupled device) and CMOS (complementary metal oxide semiconductor) sensors in digital cameras, mobile phones or autonomous vehicles. These convert light (photons) into electrical signals (electrons). But like our human eyes, these devices cannot see the important mid-IR range. This wavelength range is very important for biological science, containing valuable bio-chemical information that allows researchers to tell different biomolecules apart. The few camera technologies that exist at these crucial wavelengths are very expensive, noisy and subject to export restrictions. That is why the huge potential mid-IR light has for the life sciences so far remained unfulfilled. But researchers have proposed a new solution: “Using a really counterintuitive imaging technique with quantum-entangled photons allows us to measure the influence of a sample on a mid-IR light beam, without requiring any detection of this light” explains Inna Kviatkovsky, the lead author of the study.

There is also no conversion or so-called ‘ghost-imaging’ involved, but the technique relies on a subtle interference effect: first a pair of photons is generated by focusing a pump laser into a nonlinear crystal. This process can be engineered, such that one of the photons will be in the visible range and the other one in the MIR (invisible). The MIR photon probes the sample and is together with the visible photon and the laser sent back to the crystal. Here, quantum interference takes place - between the possibilities of the photon pair being generated on this first pass, and the possibility of not being generated on the first pass, but instead on the second pass through the crystal. Any disturbance, i.e. absorption caused by the sample, will now affect this interference and intriguingly this can be measured by only looking at the visible photons. Using the right optics one can build a mid-IR microscope based on this principle, which the team showed for the first time in their work.

“After a few challenges in the beginning, we were really surprised how well this works on an actual bio-sample.” Kviatkovsky notes. “Also we shine only extremely low powers of mid-IR light on the samples, so low, that no camera technology could directly detect these images.” While this is naturally only the first demonstration of this microscopy technique, the researchers are already developing an improved version of the technique. The researchers envisage a mid-IR microscope powered by quantum light that allows the rapid measurement of the detailed, localized absorption spectra for the whole sample. “If successful this could have a wide range of applications in label-free bio-imaging and we plan to investigate this with our collaboration partners from ECRC”, Dr. Sven Ramelow, group leader at the physics department and IRIS Adlershof of Humboldt-Universität zu Berlin, explains.

The research was funded by Deutsche Forschungsgemeinschaft (DFG) within the Emmy-Noether-Program.

Publication:
Inna Kviatkovsky, Helen M. Chrzanowski, Ellen G. Avery, Hendrik Bartolomaeus, and Sven Ramelow
„Microscopy with undetected photons in the mid-infrared.“
Veröffentlichung: 14. Oktober 2020 in Science Advances Issue 42, p. xxx

15.09.2020

IRIS-Nachwuchsforscher Michael Kathan receives prestigious award for photochemistry

For his outstanding dissertation "Photoswitching Reactivity: From remote-controlled to light-driven chemical systems", Dr. Michael P. Kathan was awarded the Albert Weller Prize on September 14, 2020. This is the second award after the Friedrich Hirzebruch PhD award 2020.

Michael Kathan, born in 1988, studied chemistry at the Free University of Berlin and ETH Zurich, where he dealt with fluorine chemistry and strained aromatics. After completing his master's degree at the Free University of Berlin, he began his doctoral thesis in 2015 in the working group of IRIS member Prof. Stefan Hecht at the Humboldt University in Berlin, funded by the German National Academic Foundation.

Michael Kathan's research focus was on the control of chemical reactivity and adaptive materials with light:
In an innovative way, he used light as a tool to control the course of chemical reactions and to control material properties. The focal point of Michael Kathan's dissertation is the development of the concept of "photo reversal", in which the chemical behavior of molecules can be fundamentally changed by the dosed irradiation with light of different colors. In their justification, the jury emphasized that Kathan had impressively managed to span the spectrum from the physicochemical basics to the manufacture of intelligent materials and new, sustainable concepts that address socially relevant issues. His research opens up access to cost-effective sensor materials that indicate, for example, the freshness of highly perishable foods. The light-controlled assembly and dismantling of plastic materials also promises progress in the area of ​​sustainable recycling of mixtures of different plastic products.

The GDCh and the German Bunsen Society awarded the Albert Weller Prize on September 14, 2020 at the digital 27th Lecture Conference on Photochemistry. This year, the award is shared by two young researchers: in addition to Michael Kathan, it was awarded to Yusen Luo, who did her doctorate at Leibniz-IPHT and the University of Jena and is now a post-doc at the Institute for Chemistry and Pharmacy at the University of Erlangen.

Kathan's research has already resulted in several publications in relevant specialist media. Since completing his dissertation in January 2019, Michael Kathan has been working on molecular motors as a postdoc with Prof. Ben Feringa at the University of Groningen, Netherlands.

We congratulate you!