Opportunities for cancer treatment and wound healing A group of researchers at the Technical University of Munich (TUM) has developed the world’s first microrobot ("microbot") capable of navigating within groups of cells and stimulating individual cells. Berna Ízkale Edelmann, a professor of Nanoand Microrobotics, sees potential for new treatments of human diseases.
Microrobots for the study of cells
They are round, half as thick as a human hair, contain gold nanorods and fluorescent dye, and are surrounded by a biomaterial obtained from algae. They can be driven by laser light to move between cells. These tiny robots were invented by Prof. Berna Ízkale Edelmann. To be exact, the bioengineer and director of the Microrobotic Bioengineering Lab has worked with her team of researchers to develop a technological platform for the large-scale production of these vehicles. They are currently being used in vitro, outside the human body.
Minirobots: a taxi ride to the cellThe TACSI microbots differ from classical humanoid robots or robotic arms as seen in factories. The entire system requires a microscope to enlarge the small-scale worlds, a computer and a laser to drive the 30-micrometer (Ám), human-controlled microbots. Another special aspect: not only can the robots be heated. They also continually indicate their temperature. This is important because, along with the ability to find their way to individual cells, they are also designed to heat the locations of individual cells or cell groups.
TACSI stands for Thermally Activated Cell-Signal Imaging. In simple terms, it is an image-based system that is capable of heating cells in order to activate them. TACSI is a "taxi" in every sense of the word: in the future, the tiny robot will "drive" directly to the location where researchers wish to study cellular processes. "In a worldwide first, we have developed a system that not only enables microbots to navigate through groups of cells. It can even stimulate individual cells through temperature changes," says Prof. Ízkale Edelmann.
How are microbots made?The production of microbots is based on ’microfluidic chips’ that model the manufacturing process. Biomaterial is injected through a channel on the left-hand side of the chip. An oil with specific components is then added from above and below through 15-60 Ám channels. The finished robots emerge on the right. In the case of the TACSI microbot, the following components are added:
- A fluorescent dye: in this case the orange rhodamine B dye is used that loses color intensity with increasing temperature. This makes the microbot an effective thermometer for the observer.
- Gold nanorods: the 25-90 nanometer (nm) precious metal rods have the property of heating rapidly (and cooling down again) when bombarded with laser light. It takes only a few microseconds to raise the temperature of the robot by 5░C. The nanorods can be heated to 60░C. Through the automatic temperature balancing process of the nanorods (known as convection), the robots are set in motion at a maximum speed of 65 Ám per second.
"This makes it possible to make up to 10,000 microbots in a single production run," explains Philipp Harder, a member of the research team.