Multimaterial 3D Nanoprinter Enables Breakthrough in Parallel Synthesis

Dr. Felix Löffler’s research has garnered two highly prestigious recognitions. The non-profit German Society for Chemical Engineering and Biotechnology has awarded him the DECHEMA Prize (€20,000). In addition, he was accepted into the German Research Foundation’s Heisenberg Program to launch his career as an academic professor. Since joining the Max Planck Institute of Colloids and Interfaces in 2017, Löffler, a physicist by training, has brought his creative vision to chemical engineering, biotechnology, and materials science. His scientific portfolio includes more than 60 articles and over 3.5 million euros in research funding. We spoke with him to find out how he's making waves in different disciplines from his office and lab in Golm, Brandenburg, Germany, and where his passion for crossing disciplinary boundaries will take him next.

Congratulations, Dr. Löffler! Your most acclaimed breakthrough is the 3D multimaterial nanoprinter. What is it?

Based on an innovative technology, the 3D multimaterial nanoprinter allows us to assemble complex chemical compounds in three dimensions at the nanoscale – billions of times smaller than a human hair. It works similarly to an old typewriter. Instead of using a metal pin to transfer ink from a ribbon to paper, a laser transfers polymer ink spots from a donor layer to an acceptor surface. These tiny solid ink spots can contain different chemical building blocks. This method eliminates the need for liquid solvents typically used in chemical synthesis; and because the solid polymer protects fragile chemicals from the environment, we can avoid issues like evaporation or spillage. A laser beam then transfers the polymer in a desired pattern onto a target surface from different donors, each containing a different building block. Afterwards, the polymer pattern is briefly melted so that the building blocks can react with each other on the surface to form new molecules - just like Lego bricks that combine into complex pieces.

What makes synthesis with the nanoprinter so groundbreaking?

Without chemical reactions, nothing would happen in and around us. Our bodies and all living creatures function thanks to these reactions, as does the production of materials. With the nanoprinter, we can trigger chemical reactions with fewer starting molecules, very quickly, and at a much lower cost. What is more exciting, we can use laser heat to synthesize as we print, providing a precise, fast, and scalable alternative to the traditional synthesis done in flasks and beakers. Scientists will be able to run hundreds of thousands of reactions at the same time.

Can you give us some examples of how your nanoprinter can become a valuable tool in every lab?

Just as we flip through books to find answers to many questions, natural scientists browse chemical libraries made up of many samples. Whether a scientist is investigating cellular functions, searching for new materials, or developing components for future medicines and vaccines, the nanoprinter can provide rapid and reliable chemical synthesis. And what’s more, it does it in miniature, on a very small surface. Imagine scientists from different fields, like chefs searching for the perfect combination of texture, taste, and smell for their reactions. With the nanoprinter, they have access to thousands of shelves of pre-mixed ingredients, all on a glass slide that fits under a microscope. Combining these ingredients and testing their properties until they find the perfect recipe becomes faster and more cost-effective. And once a suitable molecule prototype is obtained, it can be efficiently reproduced. To give you an idea, the traditional synthesis of just one compound or material in a lab can take several weeks. With Iour technology, we could generate millions within the same time frame.

You work in Peter Seeberger's Department of Biomolecular Systems, which specializes in finding leads for new vaccines and drugs. How does your nanoprinter contribute to these specific goals?

In our department, chemists synthesize complex sugars as building blocks for potential future vaccines and medicines. But this is a cumbersome process, especially because these sugars are incredibly versatile in their structure. The nanoprinter can perform 100,000 syntheses on a single tiny glass slide and thus make the path from the lab to clinical trials shorter. In fact, we have already transferred our technology to the company PEPperPRINT which is using it to produce protein fragment arrays.

Is there any other specific application you have worked on and you’d like to share with us?

So far, we’ve talked about applications in materials science and research into potential vaccines. But the nanoprinter also offers a solution to the widespread problem of product counterfeiting. We applied our ‘synthesize as we print’ to simple glucose sugar and generated fluorescent patterns that are virtually impossible to replicate. As the sugar caramelized, we fine-tuned the laser heat to control the fluorescent color of the printed pattern and even induce chaotic random micro and nanopatterns. Using caramel against forgery makes this technology not only inexpensive but also environmentally friendly. So random, in fact, that they were unique and impossible to reproduce. Imagine colorful 3D QR codes that can be read with special techniques but cannot be faked, so you can trust that your medicine has passed all relevant safety checks before it gets to the counter at your local pharmacy.

And what are your plans for the future?

I think that there is still a lot to be explored with the nanonprinter. With a pinch of creativity, its mechanism can be used to arrange the chemical building blocks in endless ways to address needs in both fundamental research and more applied areas. One idea, for example, is to print in the fourth dimension - time - to create what we call responsive soft materials. These materials can adapt their shape, color, and stiffness in response to external stimuli and can be used in many fields, from biomedicine to robotics. Another application that I want to look into is printing inorganic nanomaterials. For example, by incorporating magnetic particles into printed structures, we could design nanorobots that work in changing environments. In the coming years, I will strive to construct life-like artificial or biohybrid systems.

What do the DECHEMA Award and the Heisenberg Grant mean for your career?

These awards are a great honor and a fantastic recognition of my work. The DFG Heisenberg Grant funds a 5-year tenure-track position. Receiving validation from both academics and industry professionals through DECHEMA further motivates me to continue my research.

Now that we know more about your research, tell us how you came to study physics

This is a story I always enjoy retelling. I was torn between studying physics and medicine, even after thoroughly checking the curricula and visiting potential faculties. I decided to flip a coin, and I still vividly remember the scene, surrounded by friends. In the end, I am happy with my choice and have never shied away from learning from other disciplines. I was, for example, a visiting scholar at the Department of Infectious Diseases and Vaccinology at the University of California Berkeley, and a principal investigator in departments ranging from engineering to chemistry.

Fundamental research has the word “fun” in. What do you enjoy most about your work?

Undoubtedly, working with so many young, brilliant minds coming from diverse backgrounds, both in terms of discipline and academic culture. I love the team spirit, working together to solve a common problem, knowing that our day-to-day efforts can, in perspective, help solve problems that impact society at large. Without the strong dedication of my outstanding team, the fun times, and the support from my mentor Prof. Peter H. Seeberger, as well as my colleagues in the department and the institute, none of my achievements would have been possible. I am extremely grateful to have worked with them all.

How do you find inspiration? Are you as eclectic in your daily life as you are in the lab?

Composing and playing music has always been my break from work. It helps me return to my research with a fresh mind. When I'm not in the lab, I tend to stick to a routine and often spend time with my family and friends. Music and science are my creative happy places to let my imagination wander!

If you could change your job for a day, which one would you choose and why?

While I have always wanted to pursue an academic career, I have often wondered what a professional career in sports or music would be like. Thanks to DECHEMA and the DFG Heisenberg Program, I think I can postpone this alternative career scenario until after retirement!