Droplet scientists push the boundary between living and non-living matter

In recent years, the boundary between living and non-living matter has become increasingly blurred as scientists explore systems governed by chemistry and physics that exhibit lifelike behaviors. This intriguing field is being explored by a trio of researchers: Joe Forth, Rob Malinowski, and Giorgio Volpe, who share a fascination with "animate" droplets. These droplets are capable of responding to their surroundings in ways that resemble the behavior of living organisms.

To qualify as animate, a system must meet three criteria. First, it must be active, utilizing energy from its environment to perform tasks and do work. Second, it must be adaptive, capable of transitioning between different dynamic states in response to changes in its environment or internal states. Finally, it must be autonomous, processing multiple inputs and deciding how to respond without external intervention.

Incorporating these behaviors into droplets or systems of droplets presents significant challenges. The line between autonomous and non-autonomous systems is particularly difficult to navigate, and Volpe, Malinowski, and Forth engage in a friendly debate over whether any droplet-based system has successfully crossed this threshold.

One of the challenges in this field is its interdisciplinary nature. Volpe acknowledges that the droplet research community is working to develop a common language for discussions, but Forth humorously notes that chemists are still wary of physics, physicists are wary of chemists, and everyone fears biology. Despite these disciplinary barriers, the potential rewards of overcoming these fears are substantial. Applications of animate droplets could range from everyday consumer products, such as deodorants, to more critical tasks like oil spill cleanup.

This exploration of animate droplets is based on a Perspective article co-authored by Volpe, Malinowski, and Forth. Volpe is a professor of soft matter in the chemistry department at University College London, UK. Malinowski is a research fellow in soft matter physics in the same department, while Forth is a colloid scientist.

Their work highlights the potential for non-living systems to exhibit complex, life-like behaviors, challenging traditional distinctions between living and non-living matter. As the researchers continue to push the boundaries of droplet science, they may unlock new innovations and solutions to real-world problems, demonstrating the power of interdisciplinary collaboration.