Scientists found a bizarre material where getting crowded actually makes the particles move faster.
April 14, 2026
Original Paper
Unifying hydrodynamic theory for motility-regulated active matter: from single particles to interacting polymers
arXiv · 2604.09447
The Takeaway
Unlike almost everything else in nature that slows down when packed together, these "active polymers" hit a phase where density boosts activity. This counterintuitive discovery could lead to self-assembling materials that get more powerful as they get smaller.
From the abstract
Understanding how microscopic motility shapes emergent collective behaviors is a challenging task in active matter, especially when self-propulsion is regulated by external cues or via quorum-sensing interactions. To address this problem, we derive a closed hydrodynamics for scalar active matter with spatially-regulated motility, under general hypotheses for the microscopic dynamics of the particles' orientations. We show that, at large scales, the contribution of the latter is entirely captured