Understanding the complexity of some natural phenomena – such as dynamics of cells, swarming of bacteria, or motion of animal groups – long has been hindered by the lack of simple and pertinent experimental models. Now, researchers at the University of Central Florida have demonstrated an “all-optical’ model of living matter. 

The research, published recently in Nature Photonics, shows that suspensions of tiny objects are affected by both thermal fluctuations and additional energy that can be controlled by light, thereby creating an artificial “active medium” that allows scientists to better understand its mechanical properties.

“Living systems are typical examples of ‘active matter’ as opposed to passive matter, like common solids or liquids,” said Aristide Dogariu, a professor of optics. “Active media have unique properties that can be traced back to their constituents’ ability to convert additional energy, stored or imparted from the environment, into cooperative motion.”

Dogariu was joined in the research by Kyle Douglass, a graduate student, and by Sergey Sukhov, a research scientist at UCF’s College of Optics and Photonics. Their work demonstrates a colloidal model for active media, where varying the amount of light controls the macroscopic properties and provides means for exploring the intricate manifestations of active matter.

Dogariu said there has been significant theoretical work during the past decade but understanding the complicated mechanics of active matter in biological systems is still unsatisfactory because of the lack of controlled experiments.

Eventually, such research “may also open avenues for creating synthetic materials that could mimic properties of living matter,” he said.

The next step of the research, funded in part by the National Science Foundation, will be for the UCF team to use their model to understand some of the statistical properties of this new kind of light-matter interaction and apply them for controlling mechanical aspects of cellular processes.