A young research team is developing an open-source optical toolbox for research and ­education. The system is 3D printed and delivers images with resolutions as high as ­commercial microscopes that cost a hundred times as much

Modern microscopes that make biological processes visible cost a lot of money, are located in specialized laboratories and require highly qualified personnel. Using them to explore new, creative approaches to urgent scientific issues – for example, in the fight against infectious diseases such as Covid-19 – is reserved primarily for scientists at well-equipped research institutions in rich countries.

Benedict Diederich, René Lachmann and Barbora Maršíková want to change that. The up-and-coming researchers have developed an optical toolbox that can be used to build microscopes for a few hundred euros that deliver high-­resolution images as commercial microscopes – but cost only a hundredth or thousandth as much. With open-source blueprints, components from the 3D printer and smartphone camera, the UC2 (You. See. Too.) modular system can be combined as the research question requires – from long-term observation of living organisms in the incubator to use in optics education.

The basic building block of the UC2 system is a 3D-printable cube into which components such as lenses, LEDs or cameras can be built. Several such cubes are plugged onto a magnetic grid base plate. Skillfully arranged, this creates a powerful optical instrument.

Observe pathogens – and then recycle the ­contaminated microscope

Helge Ewers is a professor of biochemistry at Freie Universität Berlin and Charité. He uses the UC2 kit to study pathogens. "The UC2 system allows us to produce a high-quality microscope at low cost, with which we can observe living cells in an incubator," he reports. As a result, UC2 opens up areas of application for biomedical research for which conventional microscopes are not suitable.

"You hardly smuggle costly microscopes into a contaminated lab," says Benedict Diederich. The post-doc at Leibniz IPHT developed the optical toolbox together with René Lachmann in Rainer Heintzmann's "Microscopy" research department – and did so precisely because of this dilemma: Their Ph.D. colleague Swen Carlstedt, a biologist at the University Hospital, wanted to observe in the incubator how monocytes develop into macrophages in order to learn more about the growth and nutritional behavior of these scavenger cells of the immune system. The only problem was that there was no suitable microscope. "Then we'll build one ourselves," the Ph.D. students thought, using plastic parts from the 3D printer. Like Diederich's homemade microscope made from a smartphone and Blu-ray player (p. 29), they can simply be incinerated or recycled after use in the safety lab.

Building according to the Lego principle

Building according to the Lego principle – this not only awakens the inner play instinct but also opens up new possibilities for tailoring a tool. "You can quickly put together the right device to map specific cells," says Benedict Diederich. "For example, if a red wavelength is needed as excitation, you simply build in the appropriate laser and swap the filter. If you need an inverted microscope, you stack the cubes accordingly." With the UC2 system, elements can be combined depending on the required resolution, stability, duration, or microscopy method, and tested directly in a "rapid prototyping" process.

The researchers archive construction plans and software on the freely accessible online repository GitHub, so that anyone can access them, rebuild, modify and extend the setups. "With the feedback of the users, we improve the system bit by bit and keep adding new creative solutions to it," reports René Lachmann. The goal behind this is to enable open science. Thanks to the documentation, researchers all over the world can reproduce and further develop experiments. Benedict Diederich calls this vision "Change in Paradigm: Science for a Dime": to herald a paradigm shift in which the scientific process is open and accessible and researchers share their knowledge with each other.

To get young people beyond the scientific community excited about optics, the research team has developed a kit specifically for education at schools and universities. "UC2: The Box" contains a sophisticated kit that allows users to learn about and try out optical concepts and microscopy methods. "The components can be combined to make a projector or a telescope; you can build a spectrometer or a smartphone microscope," explains Barbora Maršíková, who developed the experiments and has already tested them with the UC2 team in workshops in Jena and the U.S., in Great Britain and Norway.

UC2 experiment box brings science to schools

In Jena, they have already used the kit at several schools, helping students, for example, to build a fluorescence microscope to detect microplastics. "We combined UC2 with our smartphone," reports Emilia Walther from the Montessori School in Jena. "This allowed us to build our own microscope inexpensively without any major prior optical knowledge and work out a simple method to detect plastic particles in cosmetics." With success: at the regional competition of "Jugend forscht," Emilia and her classmates Robin and Elias took first place in the chemistry category in early 2021, and second place in the technology category.

To awaken the spirit of research and the joy of experimentation - that is also the mission of UC2. "We want to make modern techniques accessible to a broad audience," says Benedict Diederich, "and build an open and creative microscopy community." Especially in the home-schooling times of the Corona pandemic, students can thus easily build their own teaching materials at home.