Synthetic Mini Motor with Enormous Power

Motion Design INSIDER

Researchers at the Technical University of Munich (TUM) have developed an artificial motor at the supramolecular level that can develop impressive power. (Image: Astrid Eckert/TUM)

Researchers have developed an artificial motor at the supramolecular level that can develop impressive power. The wind-up motor is a tiny ribbon made of special molecules. When energy is applied, the ribbon aligns itself, moves like a small fin, and can thus push objects. For the first time, the energy for this comes from a chemical fuel.

Until now, the conversion of chemical energy into rotational energy on a supramolecular level — small objects consisting of more than one molecule — was only known from biology. Primitive bacteria, known as archaea, use the chemical fuel ATP to rotate their tiny fin-like locomotion organs, the flagella, and thus move around. Synthetic replicas of this process have not existed until now. In the future, this new development could be used in nanorobots that swim through blood vessels to detect tumor cells, for example.

The peptide ribbons, developed by a team led by Brigitte and Christine Kriebisch and Job Boekhoven, Professor of Supramolecular Chemistry at the Technical University of Munich (TUM), are a few micrometers long and just a few nanometers wide. When chemical fuel is added, they gain structure and the ribbons curl up into small tubes, causing them to begin to rotate. This process can be observed live under a microscope.

The researchers discovered that they could control the rotation speed of the ribbons by the amount of fuel added. In addition, the direction of rotation — clockwise or anti-clockwise — could be influenced by the structure of the molecular building blocks of the ribbons.

Together with Professor Matthias Rief, TUM Professor of Molecular Biophysics, the researchers found that the ribbons exert enough force on their surroundings to move micrometer-sized objects. Determining the force is one of the most important practical results.

If several rotating ribbons are brought together at a central point small “micro-walkers” are created that can crawl along surfaces. After further improvements, these micro-walkers could possibly be used for medical applications such as transporting drugs in the body. However, the fuel used is not yet suitable for this, as it would be harmful to the organism.

Source