Up to now, if scientists wanted to study blood cells, algae, or bacteria under the microscope, they had to mount these cells on a substrate such as a glass slide. Physicists at Bielefeld and Frankfurt Universities have developed a method that traps biological cells with a laser beam enabling them to study them at very high resolutions. In science fiction books and films, the principle is known as the ‘tractor beam’. Using this procedure, the physicists have obtained superresolution images of the DNA in single bacteria.
One of the problems facing researchers who want to examine biological cells microscopically is that any preparatory treatment will change the cells. Many bacteria prefer to be able to swim freely in solution. Blood cells are similar: They are continuously in rapid flow, and do not remain on surfaces. Indeed, if they adhere to a surface, this changes their structure and they die.
‘Our new method enables us to take cells that cannot be anchored on surfaces and then use an optical trap to study them at a very high resolution. The cells are held in place by a kind of optical tractor beam. The principle underlying this laser beam is similar to the concept to be found in the television series “Star Trek”,’ says Professor Dr. Thomas Huser. He is the head of the Biomolecular Photonics Research Group in the Faculty of Physics. ‘What’s special is that the samples are not only immobilized without a substrate but can also be turned and rotated. The laser beam functions as an extended hand for making microscopically small adjustments.’
The Bielefeld physicists have further developed the procedure for use in superresolution fluorescence microscopy. This is considered to be a key technology in biology and biomedicine because it delivers the first way to study biological processes in living cells at a high scale – something that was previously only possible with electron microscopy. To obtain images with such microscopes, researchers add fluorescent probes to the cells they wish to study, and these will then light up when a laser beam is directed towards them. A sensor can then be used to record this fluorescent radiation so that researchers can even gain three-dimensional images of the cells.
In their new method, the Bielefeld researchers use a second laser beam as an optical trap so that the cells float under the microscope and can be moved at will. ‘The laser beam is very intensive but invisible to the naked eye because it uses infrared light,’ says Robin Diekmann, a member of the Biomolecular Photonics Research Group. ‘When this laser beam is directed towards a cell, forces develop within the cell that hold it within the focus of the beam,’ says Diekmann. Using their new method, the Bielefeld physicists have succeeded in holding and rotating bacterial cells in such a way that they can obtain images of the cells from several sides. Thanks to the rotation, the researchers can study the three-dimensional structure of the DNA at a resolution of circa 0.0001 millimetres.
Professor Huser and his team want to further modify the method so that it will enable them to observe the interplay between living cells. They would then be able to study, for example, how germs penetrate cells.
Learn more: Optical tractor beam traps bacteria
Founded in 1969, it is one of the country’s newer universities, and considers itself a “reform” university, following a different style of organization and teaching than the established universities. In particular, the university aims to “re-establish the unity between research and teaching”, and so all its faculty teach courses in their area of research. The university also stresses a focus on interdisciplinary research, helped by the architecture, which encloses all faculties in one great structure. It is among the first of the German universities to switch some faculties (e.g. biology) to Bachelor/Master-degrees as part of the Bologna process.
Bielefeld University has started an extensive multi-phase modernisation project, which upon completion in 2025 would result in completely new university buildings to replace the 40-year old main building. A total investment of more than 1 billion euros has been planned for this undertaking.
Bielefeld University research articles from Innovation Toronto
- Carrying a Table Together with a Robot – June 20, 2015
- A robot prepared for self-awareness: Expanded software architecture for walking robot Hector – April 1, 2015
- Process devised for ultrathin carbon membranes
- Algae Breaks Down Cellulose: Big Implications for Biofuels
- Synthetic Biofilter Removes Estrogens and other Medicine Residues from Drinking Water
- A robot prepared for self-awareness: Expanded software architecture for walking robot Hector
- New production method broadens the perspectives for an improved use of the “magic material” – many different forms are possible
Students at Bielefeld University of Applied Sciences have developed “Ourobot”.
Their project was supervised by a professor at the Bielefeld University of Applied Sciences and a CITEC researcher.
It looks like a bicycle chain, but has just twelve segments about the size of a fist. In each segment there is a motor. This describes pretty much the robot developed by the four bachelor students in Computer Engineering, Johann Schröder, Adrian Gucze, Simon Beyer and Matthäus Wiltzok, at Bielefeld University of Applied Sciences. The project was supervised by Professor Dr. Axel Schneider of the Bielefeld University of Applied Sciences and Jan Paskarbeit from Bielefeld University. A new video introduces the robot.
What distinguishes “Ourobot” from other comparable robots are the pressure sensors found in its chain segments which enable it to detect and overcome obstacles. The name of the robot, by the way, was inspired by an ancient Egyptian symbol depicting a serpent eating its own tail, the Ouroboros. “At the moment Ourobot can only move straight ahead and cannot manage curves yet, but its sensors can detect obstacles, such as a book, and can traverse them”, explains Jan Paskarbeit. The control mechanism behind this, i.e. the way the individual chain links interact in order to roll over an obstacle, involves a complex mathematical task. “It is remarkable how the students have solved this”, says Axel Schneider. The professor is a co-opted member of CITEC and leads a large project at the Centre of Excellence developing “Hector”, a walking robot. “There is no concrete application for Ourobot at the moment. It is a feasibility study, meaning basic research”, explains Schneider. This also makes the project exceptional, as bachelor’s projects at the University of Applied Sciences are usually application-oriented. “However, this does not rule out fundamental research projects, quite the opposite, we integrate the students early into research projects“, adds Schneider.
The collaboration with the University continues with the master’s degree in BioMechatronics, jointly offered by Bielefeld University and the Bielefeld University of Applied Sciences. Matthäus Wiltzok, who worked on the project, is now enrolled in this course. He and his colleagues are infected by the “robot virus”, and all are keen to continue working in this area.
A highlight for the team was the visit of the international robot conference ICRA in Stockholm which took place in May this year. The research paper on Ourobot* was met with great interest there. There is a long way to go, however, before the project Ourobot is concluded, as it is continually in development. The supervisors’ vision is to take the present robot that works in two dimensions “into the third dimension”, as Schneider explains. “We would like to develop a robot that actively changes its form, which can adapt to its environment like an amoeba, capable of stretching and shrinking again”, describes the professor. In this way, Ourobot can move through narrow terrain and overcome obstacles by means of different movements. The team has designed different variations of the new 3D version of Ourobot, similar to a ball or a snake. In this area, however, there is still much research to do.
A video shows Ourobot in action:
Can a robot help Germany integrate its influx of migrants? A new research project thinks the answer might be yes.
More than 1 million refugees reached Germany last year. Children represent around 25 percent of the refugees and migrants arriving in Europe, according to the International Organization for Migration.
That’s where “Nao” comes in. Researchers at Germany’s Bielefeld University are testing whether the high-tech, wide-eyed robot can help teach migrant children language skills.
“Kids respond very positively to the small humanoid robot Nao that we are programming,” said Stefan Kopp, an artificial intelligence expert working on the project. “They are highly motivated and its fun for them to interact with the technology.”