The Physics Behind Active Matter Systems

Active matter systems, composed of individual units that can move autonomously, have attracted attention in various scientific fields due to their unique properties and potential applications. Understanding how the microscopic units interact and affect the collective behavior of active matter on a macroscopic scale is crucial for harnessing their potential. Researchers at the Georgia Institute of Technology have made progress in this area by developing a new model of active matter and investigating its physics in a study published in Science Advances.

The research team focused on a suspension of self-propelled particles, such as bacteria or synthetic microswimmers, in a liquid medium. By using data from an experimental system involving suspensions of microtubules, which provide structural support to cells, they were able to study the motion and interaction of these rod-like objects. The motion of microtubules is driven by molecular motors powered by a protein called kinesin. The researchers controlled the motion of microtubules by changing the kinesin or ATP concentrations in the system.

One of the key discoveries of the study was understanding the relationship between the flow of the system and the topological defects, which describe the local orientation of microtubules. The researchers found that the dynamics of active nematics in two dimensions are controlled by the stiffness of the microtubules and the rate at which bundles of microtubules are stretched by kinesin, rather than the stress generated by the motors. These findings have important implications for understanding the emergent behaviors of active nematics and help explain previously unexplained experimental results.

This study also highlights the importance of data-driven approaches in scientific research and the dangers of traditional assumptions. The researchers emphasize that established research communities should be open to new insights and overcome confirmation bias by considering alternative models and approaches.

– Science Advances article: “Physically informed data-driven modeling of active nematics”
– Georgia Institute of Technology news release