Quantifying intracellular mechanics by a mechanical fingerprint and a new observable to detected broken detailed balance

Date

Jun 19, 2025

Time

11:00 AM - 12:00 PM

Speaker

Timo Betz

Affiliation

Faculty of Physics, Georg-August-Universität, Göttingen

Series

MPI-CBG Thursday Seminar

Language

en

Main Topic

Biologie

Host

Ricard Alert

Description

Many biological systems rely on fundamental physical principles for their proper function. Mechanical processes such as force generation, and the adaptation of stiffness and viscosity, have been successfully applied to address complex biomedical questions using physical concepts. These advances have been driven largely by innovative methods that enable the quantification of biological processes and the development of theoretical models with high predictive power. In this presentation, I will discuss our recent approaches for studying active force generation and mobility across various biological systems and length scales. Beginning with an overview of the challenges in mechanical measurements at the micro- and nanoscale within living systems, I will highlight examples where these methods have successfully explained the motion of particles inside living cells, the physical fluidization of the cytosol during cell division, and the development of mechanical fingerprints to classify different cell types. To extend this framework, we introduce a novel observable called the mean-back relaxation. This measure, related to the well-known mean squared displacement, offers the unique ability to detect non-equilibrium processes and broken detailed balance even in scenarios where traditional trajectory-based analyses fail to capture non-equilibrium components. We demonstrate that this quantity provides a robust measure of activity, both in controlled experimental setups and in complex materials such as living cells.

Last modified: Jun 19, 2025, 7:37:08 AM