When users operate their smartphones, tablets and so on, they do not give a second thought to the complicated electronics that make them work.
All that concerns them is that they can happily swipe and tap away. To make the touchscreens work, they are provided on their surface with microscopically small electrical conductor tracks, which open and close circuits when touched with a finger. At the peripheries of the devices, these microscopic tracks merge into larger conductor tracks.The researchers at the INM – Leibniz-Institute for New Materials are now presenting a novel process that allows microscopic and macroscopic conductor tracks to be produced in one step.
The INM from Saarbruecken will be one of the few German research institutions at the TechConnect World trade fair on 16 and 17 June in Washington DC, USA, where it will be presenting this and other results. Working in cooperation with the VDI Association of German Engineers it will be showcasing its latest developments at Stand 301 in the German Area.
The developers are basing the novel process on photometallization: under exposure to UV light, and acting in conjunction with a photoactive layer, colourless silver compounds turn into electrically conductive silver. The silver compound can be applied in the form of tracks or other structures to plastic films or glass by various methods. Tracks of various sizes, down to the smallest size of a 1000th of a millimetre, can be created in this way. The corresponding conductor tracks are then produced by exposure to UV light.
The films or glass are first coated with a photoactive layer of metal oxide nanoparticles. “We then apply the colourless, UV-stable silver compound”, says Peter William de Oliveira, Head of the Optical Materials Program Division. The exposure of this series of layers has the effect that the silver compound on the photoactive layer decomposes and the silver ions are reduced to metallic, electrically conductive silver. This process is said to have several advantages: it is claimed to be quick, flexible, variable in scale, low in cost and environmentally friendly. And there is no need for any further post-treatment process steps.
This basic principle allows researchers at the INM to very individually apply conductor strips of different sizes to substrates such as glass or plastic. “There are three different options that we can use as required. “Writing” using a UV laser is particularly good for the first customized production and testing of a new conductor strip design, but this method is too time-consuming for mass production”, explains physicist de Oliveira.
Photomasks that are only UV-permeable at the desired positions can also be used for structuring. “The production of these masks is quite costly and has a high environmental impact. For a “semi-continuous process” they are particularly suitable for solid substrates such as glass”, says the materials expert, but they were not suitable for a potential roll-to-roll process because they are mainly composed of quartz glass and are not flexible.
The researchers are currently focusing their efforts on a third method using so-called transparent stamps. “These stamps mechanically displace the silver complex, and where there is no silver there is also no conductor strip”, in de Oliveira’s opinion. “So we can form structures measuring just a few micrometers. Since the stamps are made of a flexible polymer, we have here the possibility of arranging them on a roll. Because they are transparent, we are working on incorporating the UV source in the roll, so the first steps would be done for a roll-to-roll process”, the Head of the Program Division sums up. This has enabled conductor strip structures of different sizes to be produced on substrates such as polyethylene or polycarbonate film on a large scale.
Dr. Peter William de Oliveira
INM – Leibniz Institute for New Materials
Head Optical Materials
INM conducts research and development to create new materials – for today, tomorrow and beyond. Chemists, physicists, biologists, materials scientists and engineers team up to focus on these essential questions: Which material properties are new, how can they be investigated and how can they be tailored for industrial applications in the future? Four research thrusts determine the current developments at INM: New materials for energy application, new concepts for medical surfaces, new surface materials for tribological applications and nano safety and nano bio. Research at INM is performed in three fields: Nanocomposite Technology, Interface Materials, and Bio Interfaces.
INM – Leibniz Institute for New Materials, situated in Saarbruecken, is an internationally leading centre for materials research. It is an institute of the Leibniz Association and has about 195 employees.
Dr. Carola Jung | idw - Informationsdienst Wissenschaft
Dielectric film has refractive index close to air
12.10.2015 | North Carolina State University
New Artificial Cells Mimic Nature’s Tiny Reactors
09.10.2015 | Department of Energy, Office of Science
Physicists of TU Berlin and mathematicians of MATHEON are so successful that even the prestigious journal “Nature Communications” reported on their project.
Security in data transfer is an important issue, and not only since the NSA scandal. Sometimes, however, the need for speed conflicts to a certain degree with...
Having a light touch can make a hefty difference in how well animals and robots move across challenging granular surfaces such as snow, sand and leaf litter. Research reported October 9 in the journal Bioinspiration & Biomimetics shows how the design of appendages – whether legs or wheels – affects the ability of both robots and animals to cross weak and flowing surfaces.
Using an air fluidized bed trackway filled with poppy seeds or glass spheres, researchers at the Georgia Institute of Technology systematically varied the...
Nondestructive material testing (NDT) is a fast and effective way to analyze the quality of a product during the manufacturing process. Because defective materials can lead to malfunctioning finished products, NDT is an essential quality assurance measure, especially in the manufacture of safety-critical components such as automotive B-pillars. NDT examines the quality without damaging the component or modifying the surface of the material. At this year's Blechexpo trade fair in Stuttgart, Fraunhofer IZFP will have an exhibit that demonstrates the nondestructive testing of high-strength automotive body parts using 3MA. The measurement results are available in a matter of seconds.
To minimize vehicle weight and fuel consumption while providing the highest level of crash safety, automotive bodies are reinforced with elements made from...
The MICADO camera, a first light instrument for the European Extremely Large Telescope (E-ELT), has entered a new phase in the project: by agreeing to a Memorandum of Understanding, the partners in Germany, France, the Netherlands, Austria, and Italy, have all confirmed their participation. Following this milestone, the project's transition into its preliminary design phase was approved at a kick-off meeting held in Vienna. Two weeks earlier, on September 18, the consortium and the European Southern Observatory (ESO), which is building the telescope, have signed the corresponding collaboration agreement.
As the first dedicated camera for the E-ELT, MICADO will equip the giant telescope with a capability for diffraction-limited imaging at near-infrared...
Self-driving cars will be on our streets in the foreseeable future. In Graz, research is currently dedicated to an innovative driver assistance system that takes over control if there is a danger of collision. It was nature that inspired Dr Manfred Hartbauer from the Institute of Zoology at the University of Graz: in dangerous traffic situations, migratory locusts react around ten times faster than humans. Working together with an interdisciplinary team, Hartbauer is investigating an affordable collision detector that is equipped with artificial locust eyes and can recognise potential crashes in time, during both day and night.
Inspired by insects
01.10.2015 | Event News
30.09.2015 | Event News
17.09.2015 | Event News
13.10.2015 | Trade Fair News
13.10.2015 | Physics and Astronomy
13.10.2015 | Health and Medicine