Day: December 11, 2023

The original version of this story appeared in Quanta Magazine.

Luca Giomi still remembers the time when, as a young graduate student, he watched two videos of droplets streaming from an inkjet printer. The videos were practically identical—except one wasn’t a video at all. It was a simulation.

“I was absolutely mind-blown,” said Giomi, a biophysicist at Leiden University. “You could predict everything about the ink droplets.”

The simulation was powered by the mathematical laws of fluid dynamics, which describe how gases and liquids behave. And now, years after admiring those ink droplets, Giomi still wonders how he might achieve that level of precision for systems that are a bit more complicated than ink droplets.

“My dream is really to use this much predictive power in the service of biophysics,” he said.

Giomi and his colleagues just took an important step toward that goal. In a study published in Nature Physics, they conclude that sheets of epithelial tissue, which make up skin and sheathe internal organs, act like liquid crystals—materials that are ordered like solids but flow like liquids. To make that connection, the team demonstrated that two distinct symmetries coexist in epithelial tissue. These different symmetries, which determine how liquid crystals respond to physical forces, simply appear at different scales.

The team’s insight could make it easier to apply the precision of fluid dynamical simulations to living tissues. If so, Giomi hopes to predict how human tissues move and deform during processes ranging from wound healing to cancer metastasis.

Luca Giomi suspects that some living tissues act like liquid crystals.

Courtesy of Luca Giomi