Toward Living Matter with Colloidal Particles
There are three basic properties of living systems that we aim to emulate with colloidal particle*
[Reprinted with permission from APS ©2017]
Understanding the differences between inanimate matter and living matter is one of the fundamental unsolved problems of science. Although this question might be framed as philosophical, there are many fundamental and practical reasons to pursue the development of synthetic materials with the properties of living ones. In the Colloquium published in the latest issue of Reviews of Modern Physics*, Dr. Zorana Zeravcic from ESPCI (Paris, France), Prof. Vinothan Manoharan, and Prof. Michael Brenner discussed how the properties of living systems might be duplicated in the laboratory, using synthetic, inanimate components.
There are three fundamental properties of living materials that sicentists seek to reproduce: The ability to spontaneously assemble complex structures, the ability to self-replicate, and the ability to perform complex and coordinated reactions that enable transformations impossible to realize if a single structure acted alone. The conditions that are required for a synthetic material to have these properties are currently unknown. This Colloquium examines whether these phenomena could emerge by programming interactions between colloidal particles, an approach that bootstraps off of recent advances in DNA nanotechnology and in the mathematics of sphere packings. The argument is made that the essential properties of living matter could emerge from colloidal interactions that are specific - so that each particle can be programmed to bind or not bind to any other particle - and also time dependent - so that the binding strength between two particles could increase or decrease in time at a controlled rate. There is a small regime of interaction parameters that gives rise to colloidal particles with lifelike properties, including self-assembly, self-replication, and metabolism. The parameter range for these phenomena can be identified using a combinatorial search over the set of known sphere packings.
*see Zorana Zeravcic, Vinothan N. Manoharan, and Michael P. Brenner, "Toward living matter with colloidal particles," Rev. Mod. Phys. 89 (13 Sep 2017) DOI: 10.1103/RevModPhys.89.031001.