- J. Čejková, T. Banno, F. Štěpánek, M.M.Hanczyc (2017). "Droplets as Liquid Robots". Artificial Life, 23 (4), 528-549.
The word “robot” was first introduced in 1921 in a Czech play R.U.R. - Rossum’s Universal Robots, where robots are not clanking metal constructions, but human-like beings made of soft matter with no wheels, no electric power and no computer systems to control them. They are based only on chemical principles and consisting of colloidal substances. The author of the play, Karel Čapek, describes them as being made of a protoplasm - a substantive essence of living matter (…“a blob of some kind of colloidal jelly that even a dog wouldn’t eat”…). In this way we can consider a droplet based on chemical principles and activated through fluid dynamics to be an embodiment of robotics more sympathetic to Čapek’s original conception. We introduce droplets as animated soft matter. We argue that droplets can be considered as liquid robots possessing some characteristics of living systems. In particular, the life-like properties and behavior of liquid robots, such as autonomous movement, self-division, ability to change shape, group dynamics and collective swarm behavior are discussed.