Plate Nº 42 · recorded November 1, 2026
Chemistry & MaterialsReported finding
Single-Molecule Motor Spins on Electricity, Boosts Conductivity 100-Fold
An Archimedes-screw molecule wired between gold tips spins on electric current and raises conductivity up to 100-fold, researchers report in Nature.
By Nathan Brooks4 min read768 words
In brief
- A single spiral molecule reverses rotation when voltage polarity flips, published in Nature on November 1, 2026.
- Rotation boosts the molecule's electrical conductivity by up to 100 times.
- It is the first current-driven molecular motor wired to two metal electrodes with controllable rotation direction.
- Design borrows from the Archimedes screw, a machine over 2,000 years old.
- Quantum simulations ran on the University of Augsburg's LiCCA supercomputer.
A molecular motor modeled on the 2,000-year-old Archimedes screw can spin in either direction on command, and its rotation can boost electrical conductivity by up to 100 times. Researchers from Germany, Denmark, Israel and China published the result in Nature on November 1, 2026.
The machine is a single spiral-shaped molecule, just a few millionths of a millimeter across, suspended between two gold tips sharpened to atomic dimensions. Flip the voltage's polarity and the molecule reverses its spin. The team says it's the first molecular motor driven by electrical current, firmly wired to two metal electrodes, whose direction of rotation can be controlled.
How does an ancient screw become a nanomotor?
The Archimedes screw has moved water uphill for over two millennia using a rotating spiral. The researchers borrowed that geometry, replacing water with electrons.
As current flows through the spiral molecule, the electrons hand off angular momentum to the structure, spinning it — much the way moving air turns a wind turbine. The spiral's handedness, right- or left-threaded like an ordinary screw, sets how it responds to the flow. Above a certain voltage threshold, the motion becomes continuous rotation.
Who built it, and how?
The spiral molecule came from the lab of Prof. Michael Pittelkow at the University of Copenhagen. It anchors to gold through sulfur atoms built into its structure.
Profs. Oren Tal and Anil Kumar Singh at the Weizmann Institute of Science in Israel then trapped individual molecules between the atomically sharp gold electrodes. Adjusting the gap between the tips let them stretch or compress the molecular screw before switching on the voltage.
Earlier electric molecular motors, first built in 2011, needed the tip of a scanning tunneling microscope to drive them along a surface. The new design runs entirely on current through a wired junction.
Why did conductivity jump 100-fold?
The measurements turned up a surprise: the rotating molecule conducted electricity far better than the same molecule at rest. Prof. Fabian Pauly's group at the University of Augsburg, with PhD students Léon Martin and Yuta Ito, chased the effect with quantum mechanical simulations on Augsburg's LiCCA supercomputer.
The answer was counterintuitive. Some of the molecule's most conductive positions are exactly the ones it avoids when stationary — rotation is what makes them reachable.
"The surprising thing is that it is precisely the positions that the molecule avoids when at rest that conduct electricity best. It is only the rotation that makes these positions accessible," Léon Martin explained.
Depending on the molecule's angle, conductivity shifted by as much as two orders of magnitude — a factor of 100.
What did theory add?
Experiments alone couldn't settle the mechanism, because the instrument only registers the current. The Augsburg team joined forces with Per Hedegård of the Niels Bohr Institute in Copenhagen and Jing-Tao Lü of Huazhong University of Science and Technology in Wuhan.
Together they built a simplified theoretical model that reproduced both the observed rotation and the current increase.
"In the experiment, you only see the current. Our calculations allow us to glimpse what is happening inside the nanocontact. It was only through close collaboration between experiment and theory across several countries that the mystery of the current increase could be solved," said Yuta Ito.
What could it be used for?
The work is early-stage, and the researchers hedge their language accordingly. Possible directions include molecular electronic components, spintronics — technology that exploits properties of electrons beyond their charge — and microfluidic systems handling minute fluid volumes.
The deeper payoff may be conceptual. The motor converts electricity into controlled rotation, and that rotation in turn controls the current flowing through it.
"We have shown that an electric current can be used to generate a directed rotation and that this rotation, in turn, controls the current. This is a new operating principle for machines at the very limits of miniaturization," Pauly said.
The field has form: artificial molecular machines earned the 2016 Nobel Prize in Chemistry, and nature's own versions — motor proteins inside living cells — have inspired decades of effort.
Who funded it?
The Augsburg work was funded by the German Research Foundation (DFG) through Collaborative Research Center SFB 1585 (project 492723217), with simulations on the LiCCA supercomputer (DFG project 499211671). Partner institutions received support from the European Research Council (Horizon 2020, Grant 864008), the Israel Science Foundation (2129/23), the Minerva Foundation, the Villum Foundation, the Novo Nordisk Foundation, the Independent Research Fund Denmark, and two Chinese programs — the National Key Research and Development Program and the National Natural Science Foundation of China.
via dx.doi.org (Original)
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