The junction is the key

Researchers decrypt transport dynamics of porous media. (Image: Pixabay CC0) - What laws govern how chemicals pass through filters? How do droplets of oil move through layers of stone? How do blood cells travel through a living organism? A team of researchers led by the Technical University of Munich (TUM) and the Max Planck Institute for Dynamics and Self-Organization (MPI-DS) has discovered how pore space geometry impacts transport of substances through fluids. Concentration takes energy. As you read this article, the blood vessels in your brain expand and the speed of the blood stream slows so that your 'reading neurons' receive more glucose and oxygen molecules from the blood stream. "This all happens without any action on our part. Through evolution, nature has developed the ability to adapt the blood flow exactly to suit the changing requirements of organisms," explains Karen Alim, TUM Professor for Theory of Biological Networks and Max Planck Research Group Leader at the MPI-DS. "Our objective is to understand the physics underlying this adaptive network." The research team, which included scientists from Nottingham Trent University, is now a large step closer to this goal: For the first time, their new model describes how the transport of substances through complex porous media is controlled by the microscopic structures of the media.