Every third year, the CDG Award for Research and Innovation is presented to Josef Ressel Centres in recognition of their success in research as well as their contribution to strengthening Austria's innovative strength and competitiveness. In 2022, the award ceremony will coincide with an anniversary: The first Josef Ressel Centre funded by the Christian Doppler Forschungsgesellschaft started on 01.10.2012.
With Sandra Stroj from the FH Vorarlberg and Günther Mayr from the FH Upper Austria, the CDG Prize 2022 goes to two materials researchers with very different focuses: one JR Centre is concerned with new areas of application for ultrashort pulse lasers, the other with the non-destructive testing of lightweight components - both with significant importance for the respective corporate partners.
"Both JR Centres show that research work based on a company's research question is highly relevant to society:Increases in efficiency in the non-destructive testing of industrial products not only increase the competitiveness of corporate partners, but are also part of the solution to our environmental challenges through the associated conservation of resources.The scientifically sound search for new areas of application for ultrashort pulse lasers leads to new approaches for cancer treatment, to new possibilities for extracting drinking water from mist using functional surfaces and at the same time opens up new customer groups for the corporate partner."
Martin Gerzabek, President of the Christian Doppler Forschungsgesellschaft
Sandra Stroj: Drinking water extraction and quantum optics
Ultra-short pulsed lasers work with laser pulses in the femtosecond and picosecond range (10-15 to 10-12 seconds). Compared to conventional lasers, they have the advantage that the processed material does not become hot. Brittle and particularly hard materials can also be processed and materials can be structured with high precision down to the nanometre range.
These high-tech lasers were originally developed for scientific research, but their applications in the industrial sector are becoming increasingly diverse. This is precisely where Sandra Stroj and the JR Centre for Material Processing with Ultrashort Pulsed Laser Sources come in: She is researching everything that can be done with these lasers. This not only requires precise knowledge of how the laser source works, but also of the properties of the material being analysed.
The company partner High Q Laser GmbH (part of MKS Instruments, Inc.), a leading manufacturer of ultrashort pulse lasers, benefits by opening up new areas of application for its product and by strengthening its expertise in advising and supporting customers.
Example: Functional surfaces modelled on a desert beetle
The desert beetle (Stenocara gracilipes) extracts water from the morning mist by holding its wings in the mist. Tiny, water-attracting hills and water-repellent valleys are found close together on these wings. This creates small balls of water that roll towards the beetle's mouth, allowing it to extract significantly more water from the fog than would be possible with smooth surfaces.
The team led by prizewinner Sandra Stroj has succeeded in reproducing this principle using a combination of a coating process and processing with ultrashort pulsed lasers. The result is a manufacturing process for functional surfaces on which any desired wetting states can be created and combined. The process has been scientifically published and patented by the company partner. It is commercialised as ClearSurfaceTM by the company partner. Possible applications range from combating condensation on industrial machinery to the production of drinking water in dry areas close to the sea, which requires neither an energy supply nor complex systems.
Example: Destroying tumours with laser light
In this method, light is introduced via glass fibres directly into tumour tissue that has previously been enriched with photoactive substances. This causes the light to be strongly absorbed locally, which ideally leads to selective destruction of the tumour.
It is essential that the light reaches the right place at the end of the glass fibres. A case for the ultra-short pulsed lasers: with these it is possible to process only the inside of the micrometre-thin glass fibres in such a way that scattering centres are created there, which scatter the light in a defined manner. A significant advance in cancer treatment.
Example: Actuators made of piezo material for quantum optics
Piezo single crystals are thin, extremely porous and temperature-sensitive materials that expand and contract when an electrical voltage is applied. For scientific investigations in quantum optics, this material must be brought into complex structures - a task for ultrashort pulsed lasers and Dr Stroj's working group. The piezo actuators produced in this way are a worldwide novelty and are successfully used in the field of quantum optics, a subject area with high scientific relevance.
Success for the corporate partner
"Thanks to the close and extremely successful collaboration between the Vorarlberg University of Applied Sciences and our company within the Josef Ressel Centre, important issues in the field of microstructuring with ultrashort pulsed laser systems have been scientifically investigated and new fields of application in the industrial sector have been opened up.In particular, the functionalisation of surfaces should be mentioned here: thanks to the outstanding work of Dr Sandra Stroj's team, for example, hydrophobic (=water-repellent) and hydrophilic (=water-loving) surface structures could be produced which, among other things, could protect aircraft wings from icing in the near future; this would mean that the use of harmful aircraft de-icing agents in winter could be largely dispensed with.Another very interesting field of application concerns the targeted control of liquids (such as human blood) in so-called micro-fluidic systems (also known as lab-on-a-chip components), which could be used to automatically analyse the smallest quantities of a liquid, for example.
Working with Dr Stroj and her team for several years has once again shown me how important and valuable the close exchange between academia and industry is and how quickly new insights can be gained - which are both scientifically valuable and industrially interesting - when experts from science and industry work together."
Dr Jürg Aus der Au, Senior Director of Engineering, High Q Laser GmbH/MKS Instruments, Inc.
Günter Mayr: Inspecting components faster and more cost-effectively
Whether air inclusions or poor bonding - the testing of critical lightweight components, e.g. for the aerospace industry, is of great economic importance to companies. Research into this is extremely relevant for the location, faster and more precise testing methods increase product quality and reduce rejects. The need for expensive repairs decreases and the competitiveness of the companies involved increases.
The team of prizewinner Günther Mayr at the University of Applied Sciences Upper Austria is focussing on the further development of thermographic testing methods: The component is irradiated with light (often halogen spotlights), the component absorbs the light and the surface heats up. As a result, the temperature on the outside is higher than on the inside, and the heat flows evenly inwards due to the temperature gradient - if the component is free of defects. If there is a defect in the component (air bubble, adhesion, etc.), heat builds up, which becomes noticeable on the surface as a measurable hotspot. This means that measurements are only ever taken on the surface without contact, making the method completely non-destructive.
It's magic!
The results of the temperature measurements are now mathematically converted as if they were an ultrasonic field - and this opens the door to a variety of methods and procedures for material testing. This amazing method was developed in Upper Austria (University of Applied Sciences Upper Austria, RECENDT Linz) and is already being used by FACC, for example, to test simple thin components, as it is many times faster and more efficient than other methods.
The maths: an ill-posed inverse problem
The JR Centre is now working on improving the solution so that it can also be used for thicker materials, hybrid composites or complex-shaped components. The problem is a well-known mathematical one and is called the ‘Fredholm integral of the first kind’. Specifically, the problem is that the contrasts become increasingly ‘blurred’ as the heat spreads through the component - in other words, information is lost over time. It becomes difficult to calculate ‘Where exactly was the defect’.
The JR Centre relies on a combination of artificial intelligence and an iterative process supported by experiments to find a solution: additional information on the spread of heat, e.g. that a defect is only ever localised, is mathematically packaged and contributes to a significantly improved spatial resolution. In particular, the position and size of the defect can be determined much more precisely in this way.
The JR Centre, with its interdisciplinary cooperation between materials research/testing, signal processing and mathematics, offers an ideal environment for this research. The results are used by the company partners to develop better, faster and more efficient testing methods, which benefits the competitiveness of the companies as well as Upper Austria as a centre of business and science.
The Start Up
Another tangible success of the JR Centre is the newly founded start-up voidsy, which was founded in September 2022 under the leadership of two recent PhD graduates from the JR Centre. The aim of the company, which is located in the immediate vicinity of the UAS, is to develop a smart sensor head for thermographic tests that will replace the complex test set-up previously required for the tests.
Successes for the company partners
"With the help of digitalisation, production systems will contribute more and more to the optimisation of component quality in the future.To do this, we need information on product characteristics.The aim is to be able to inspect all parts fully automatically and within the cycle time of the system.With the outstanding research results achieved by the Josef Ressel Centre for thermographic non-destructive testing of composite materials, we have taken a significant step forward here."
Dr Norbert Müller, Head of Global Application Technology, ENGEL AUSTRIA GmbH
"Through the collaboration with Dr Mayr and especially through the JR Centre, FACC became the first aerospace supplier to BOEING and AIRBUS to use infrared thermography as a primary inspection method in production; an achievement that is still unmatched by many large companies in the industry and of which we are very proud.Thanks to Dr Mayr and his team!
We are actively using this highly efficient technology in our production for several parts.It offers several key advantages in terms of inspection time (up to 20 times faster), purchase costs (approx. 80% less) and maintenance (approx. 10% cheaper), as well as increasing safety, resource and energy efficiency.This has significantly strengthened our position on the European and international markets."
Helmuth Höller, Head of Quality, FACC Operations GmbH
"We are a manufacturer of an industrialised thermographic measuring cell for the non-destructive testing of components, which is used in the industrial environment for e.g. moulded parts / fibre composites etc., as well as for electronics testing.
The cooperation with the Josef Ressel Centre (JRZ) under the direction of Dr Mayr enables Ottronic to keep industrialised customer solutions and in-house quality assurance processes at the cutting edge of technology, to continuously improve them and to adapt them to market requirements.By incorporating the methods and algorithms developed at the JRZ, we are able to expand the field of application and continuously improve the informative value of the test results in order to make hidden component defects such as blowholes or inclusions visible practically in the machine cycle and thus optimise production processes more efficiently in terms of their quality."
Josef Ott, Managing Director of Ottronic Regeltechnik Gesellschaft m.
