Title: How Motion, Force, and Collective Behavior Organize Living Matter

Speaker: Dr. Pranay Mandal, Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany

Abstract: Living systems are multicomponent, heterogeneous, and far from equilibrium, making them fundamentally different from materials traditionally studied in physics. Their structures and functions emerge not from static building blocks, but from forces, motion, and collective responses spanning molecular to cellular scales. In the first part of my talk, I address this question using active matter systems built from magnetically actuated nanobots. These precisely controlled units provide direct experimental access to non-equilibrium phenomena such as brownian ratchets, torque driven dynamics, and the consequences of temporal reciprocity when it is preserved. As simplified yet powerful soft matter platforms, they expose the physical principles governing motion and organization far from equilibrium. But the principles revealed in controlled systems must ultimately confront biological complexity. In the second part of my talk, I therefore move into this regime, focusing on reconstituted DNA and chromatin assemblies studied in vitro. Using optical tweezers, complemented by AFM and fluorescence microscopy, I quantify how DNA protein assemblies undergo phase transitions, bear tension, reorganize under load, and generate emergent mechanical properties. By connecting molecular scale force measurements to nuclear scale organization and morphology, this work demonstrates how soft matter physics and force spectroscopy can uncover the physical principles underlying genome organization, advancing a quantitative "physics of life".