Event

Structural color and transparency are common phenomena in life - these optical properties are found in many species of mammals, birds, insects, and even bacteria. This talk discusses our recent discovery that a broad class of two-dimensional optical materials found throughout the tree of life exhibits disordered stealthy hyperuniformity, and this property in turn generates the observed living optical phenomena. We first calculate the parameters characterizing the degree of hyperuniformity in each living system, and extract corresponding spectral densities and structure factors. We then construct molecular dynamics simulations of the living systems using pair potentials derived from the observed, living interactions. These MD simulations, unlike the raw image data from which they are derived, are sufficiently large to capture electromagnetic interactions across the visible spectrum. Finite-difference time domain calculations of the optical behavior of these systems near equilibrium generally recapitulate the experimentally observed optical properties of the tissues, while similar systems with slight size distortions or small modulations of the pair-potentials do not, demonstrating that hyperuniformity provides a useful and thermodynamically rationalized framework for the origins of the optical properties of these soft, evolved optical materials.