title: Bütschli dynamic droplet system.
abstract: Dynamical oil-water systems such as droplets display lifelike properties and may lend themselves to chemical programming to perform useful work, specifically with respect to the built environment. We present Bütschli water-in-oil droplets as a model for further investigation into the development of a technology with living properties. Otto Bütschli first described the system in 1898, when he used alkaline water droplets in olive oil to initiate a saponification reaction. This simple recipe produced structures that moved and exhibited characteristics that resembled, at least superficially, the amoeba. We reconstructed the Bütschli system and observed its life span under a light microscope, observing chemical patterns and droplet behaviors in nearly three hundred replicate experiments. Self-organizing patterns were observed, and during this dynamic, embodied phase the droplets provided a means of introducing temporal and spatial order in the system with the potential for chemical programmability. The authors propose that the discrete formation of dynamic droplets, characterized by their lifelike behavior patterns, during a variable window of time (from 30 s to 30 min after the addition of alkaline water to the oil phase), qualify this system as an example of living technology. The analysis of the Bütschli droplets suggests that a set of conditions may precede the emergence of lifelike characteristics and exemplifies the richness of this rudimentary chemical system, not only for artificial life investigations but also for possible real-world applications in architectural practice.
authors.affiliation: University of Greenwich.
authors.forename: Rachel
authors.initials: R
authors.lastname: Armstrong
authors.forename: Martin
authors.initials: M
authors.lastname: Hanczyc
mesh_terms: D000468:Alkalies / Q000737:chemistry; D000656:Amoeba / Q000502:physiology; D008954:Models, Biological; D000069463:Olive Oil; D010938:Plant Oils / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000468:Alkalies; D000069463:Olive Oil; D010938:Plant Oils; D014867:Water