Studying Biological Flows Using Beads and Liquid Beams: Dr. Mathijssen and Ernest Park

The passion for kitchen physics has not gone away since Dr. Mathijssen returned to the lab. The coffee study was partly inspired by a scientist in his group who kept detailed notes about pour-over brews prepared in the lab each day. The notes included information about where the beans had come from, the extraction time and the brew’s flavor profile.

Dr. Mathijssen primarily studies the physics of biological flows, such as the way bacteria swim upstream in blood vessels. He started playing with his food when he lost his lab access during the Covid-19 shutdown. He slid coins down the slopes made from whipped cream and honey, shook up bottles of whiskey and tested the consistency of pasta. The review was structured like a menu of the physics involved in making a meal.

Ernest Park, a graduate student in the lab, designed a formal experiment. The scientists filmed the act of water being poured over coffee grounds from various heights using a high-speed camera because they were able to imitate it in real life using silica gel beads.