ExpertTalk - Optical Measurement Technology: Where Dirt Doesn't Stand a Chance!

In our new interview series “ExpertTalk”, a colleague of the Fraunhofer Business Unit Cleaning presents an innovative technology in the field of cleaning. He discusses the competencies, possibilities, and limitations of the technology and where it is applied. Of course, a humorous anecdote or two from daily life in developing these technologies should not be missed. This time, Dr. Alexander Blättermann from Fraunhofer IPM was up next. He talks about unique systems for testing cleanliness worldwide and why he sometimes has to crawl in the dirt with them.

1.    What specific cleaning technology does your institute offer?

At Fraunhofer IPM, we specialize in optical measurement technology. In fact, we do not offer cleaning technology, but techniques and systems for testing the cleanliness of components and other surfaces. Our focus here is on seamless testing with maximum sensitivity and process suitability. To this end, we develop various systems such as the ‘F-Scanner’ or the ‘F-Camera’ and customize them to the respective task.

2.    What competencies does your institute offer in relation to this technology?

Our systems combine a whole range of expertise from different areas. Fluorescence measurement technology is fundamental here: Fraunhofer IPM has been carrying out research and development in various contexts in this area for many years. It is the basis for our technology. Then there are technical aspects such as laser scanning and camera technology, which allow us to develop imaging systems. Particularly important for success in practice is the step towards a real system, i.e. a measuring device that can run 24/7 at the user's premises and be fully integrated. This is an intensive collaboration between mechanical engineers, electrical engineers, software developers, the mechanical workshop at Fraunhofer IPM and the scientists, which has been established over many years.

3.    Why should one choose your service rather than opting for a solution available on the market? What advantages does it offer to the costumer?

Our systems are unique worldwide and we adapt them flexibly and in every respect to customer requirements. We operate, so to speak, special machine construction for newly developed measurement technology for cleanliness testing: Larger field of view - no problem! Higher resolution - no problem! Housing in RAL 7048 pearl mouse gray - no problem!

4.    In which industry and for what cleaning tasks is the technology primarily applied?

The topic of e-mobility is currently the one that concerns us the most. This future technology comes with many modern joining processes and sometimes very high-quality requirements. Quality assurance is often indispensable here - especially when it comes to safety-relevant components. Two specific applications are, for example, the cleanliness of copper welds on power electronics (direct copper bonding) and the cleanliness of various housing parts (motor, battery, control units, driver assistance systems, brakes) before bonding or sealing. In addition to electromobility, we also have applications in other high-tech sectors such as the hydrogen economy, medical technology and aerospace.

5.    Were there any amusing or interesting incidents during the development or application of the technology?

Our technology can also be used to measure intentional coatings. These are, for example, lubricant films on metal sheets before they are pressed into automotive parts such as doors, roofs or hoods. This means that we are sometimes out and about with our highly sensitive measuring devices in extreme environments such as a press line, where we are crawling in the dirt and lying in puddles of oil screwing on the devices.

6.    What does the future hold for this technology? What direction is it heading, and what developments can we expect?

We are constantly trying to push technology and systems further - both in terms of basic measurement technology and the design and implementation of customer-specific systems. Our aim is to constantly redefine the limits of what is technically feasible in terms of detection limits, resolution, speed, etc. and to realize systems with maximum reliability. However, it is important to keep a close eye on costs so as not to restrict the user group too much.

7.    What specific services do you offer in the field of cleaning technology? (e.g., seminars, services, development of customized process technology, etc.)

With regard to cleanliness testing, Fraunhofer IPM offers the development and production of customer-specific systems. We develop turnkey systems with software, operating instructions, warranty, CE and everything else that is required. We also offer studies and test measurements and are happy to make our reference systems available for customer trials.

8.    What has been the most interesting project you have worked on in this field?

I find it particularly exciting when several projects intertwine. Last year, we implemented a system for testing engine components for a German car manufacturer. The identical sister system was delivered to the supplier abroad. Both systems are currently being used for small-scale testing. We are now working on two further developed systems that will be integrated into the series production of these engines in the future in order to implement 100% testing in 24/7 operation.