Jul 03, 2026

Programmable molecular machines are getting closer

Researchers created a highly stable electrically controlled DNA origami switch that regulates molecular functions and keeps working through hundreds of thousands of cycles.

(Nanowerk News) The development of programmable molecular machines is moving closer. Researchers at the Technical University of Munich (TUM) have now developed an extremely reliable and stable DNA switch. It can be controlled electrically and used to regulate molecular functions. The nanoscale switch remained functional over several hundred thousand switching cycles.

The findings ahve been published in Science Robotics ("A high-endurance DNA origami snap-through switch for functional nanoscale control").

The switch is based on DNA origami, where DNA strands are folded into precisely defined, nanoscale components. Using this technique, the team created a DNA switch with two stable positions. A short electric pulse is sufficient to move the structure from one position to the other within milliseconds. After that, it remains in its new position without any further energy input.

This is an important step for the development of molecular machines. Such systems must not only be switched in a controlled manner, but also operate reliably over extended periods. This is exactly what the new switch demonstrates: In the experiments, individual devices remained stable for hours, withstanding more than 200,000 switching cycles and, in an additional setup, still showing robust switching behavior even after around one million actuations.

Two potential applications already demonstrated

“With our design, we were able to show that a DNA-based switch can not only be controlled quickly and precisely, but is also exceptionally long-lived,” says Prof. Friedrich Simmel, Professor of Physics of Synthetic Biological Systems at the TUM School of Natural Sciences. “This makes it more realistic to use DNA-based components as functional elements of future molecular machines.”

The research team has already tested two possible applications. In one experimental setup, the switch was coupled to gold nanorods. In this way, an optical signal could be turned on and off depending on the position of the switch. In a second experiment, the team used the switch to alternately expose or shield a binding site for other DNA strands. This made it possible to control the speed of this binding process.

The study thus does more than introduce a single new nanoscale component. It also provides a basis for systematically investigating durability, wear, and potential failure modes of molecular switches. First author Florian Rothscher says: “In the future, such electrically controllable DNA systems could be of interest for molecular information processing, for optical nanodevices, and for the targeted control of chemical reactions.”

The experiments were carried out under controlled laboratory conditions and in specialized measurement setups. The results show that the concept works reliably under these conditions. However, further development steps will be necessary before potential technical applications outside such laboratory environments become feasible.

Source: TU Munich (Note: Content may be edited for style and length)