A team of researchers at the University of Illinois Urbana-Champaign has shown, through high-resolution molecular dynamics simulations, that a DNA double helix rotating inside a carbon nanotube can transport water and ions against a concentration gradient, a molecular-scale version of the Archimedes screw, one of humanity’s oldest pumping mechanisms.
The study, posted as a preprint on bioRxiv, demonstrates that the principle of a helical screw pump, invented more than 2,000 years ago to lift water for irrigation, can be translated to a scale where gravity and inertia are negligible forces.
How it works
The DNA duplex acts as the helical blade of an Archimedes screw at the nanoscale. When rotated inside a carbon nanotube, the DNA’s natural helical shape scoops up water and ions, transporting them through the tube. The mechanism differs for each cargo: water transport is driven primarily by the steric shape of the rotating duplex, the physical sweeping motion drags water molecules along. Ion transport, particularly for cations, is faster and driven by electrostatic interactions between the negatively charged DNA backbone and the positively charged ions.
Crucially, the torque-driven duplex can move ions against a concentration gradient, from low to high concentration, the defining characteristic of a pump and the feature that makes the Archimedes screw principle meaningful at the molecular scale.
The rotation-induced ion flux depends on the specific cation type, raising the possibility of ion separation at the nanoscale.
Simulation only, for now
The study, by Xavier Mleziva, Christopher Maffeo, and Aleksei Aksimentiev of UIUC’s Department of Physics, is entirely computational. As the Science news article by Julia Vaz notes, the engineering challenge of “fitting and securing a DNA double helix inside a carbon nanotube” in the real world remains unsolved. No experimental realization has been demonstrated.
Why it matters
This is the first demonstration that a macroscopic pump principle can work at the molecular scale using a naturally occurring biological helix. Macroscopic pumps rely on gravity and inertia, forces that are effectively zero at the nanometer scale, making the translation far from trivial.
Potential applications, if experimental realization can be achieved, include lab-on-a-chip technologies for moving molecules at tiny scales, separation and concentration of biological matter, and molecular-scale fluid handling.
The research was funded by the National Science Foundation (ID-2411133).
Disclosure: Based on a bioRxiv preprint that has not undergone peer review. The study is entirely computational (molecular dynamics simulations) with no experimental realization.
Sources:
1. Mleziva X, Maffeo C, Aksimentiev A. “DNA: A Nanoscale Archimedes’ Screw.” bioRxiv. 2026. DOI: 10.64898/2026.06.25.734429
2. Reported in Science AAAS. https://www.science.org/content/article/dna-could-act-famed-gravity-defying-pump