Tiny artificial motors actually speed up the more crowded they get, which is the opposite of how traffic works.
March 24, 2026
Original Paper
Regulation of propulsion in assemblies of thermophoretic nanomotors
arXiv · 2603.20753
The Takeaway
Unlike human traffic which slows down in a crowd, these heat-driven particles use a feedback loop where their own density boosts the temperature around them. This creates a synergy that propels them at 'ultrafast' speeds—thousands of times their own body length per second.
From the abstract
Active particles locally transduce energy into motion, leading to unusual and emergent behaviors. However, current synthetic particles lack sensing and adaptation mechanisms. Here, we demonstrate a novel regulation pathway, through the combined use of thermophoretic propulsion and nanometric building blocks. We build an active fluid composed of artificial nanomotors and study its three-dimensional (3D) dynamics. We use laser-induced photo-thermal effect to actuate nanoparticles, and probe their