Fluctuations of active membranes with nonlinear curvature elasticity

Thermal fluctuations (eventually) unfold nanoscale origami

“…Molecules within the two membranes fluctuate about their mean positions at finite temperature-leading to deformations, or undulations, of the top and bottom membranes. To characterize the deformed microstates of the sheets, we draw inspiration from past work on the statistical mechanics of biological membranes and utilize the Monge gauge [36,40,49]. The Monge gauge, h : Ω ∪ Ω ′ → R, is a scalar displacement field where the displacement is assumed orthogonal to the plane of the folded, but otherwise flat, top and bottom membrane 2 .…”

“…The applications at the intersection of biophysics and biomedicine seem to be plentiful e.g. active matter [49], DNA origami, among others. γ → ∞.…”

Spontaneous crumpling of active spherical shells

“…Crucially, we show how a crumpled phase, develops systematically and reliably for sufficiently large active forces. While a significant amount of work has been done to understand the structural and dynamic properties of active linear and ring polymers, [39][40][41][42][43][44] and more recent work considered the behavior of fluid vesicles in the presence of active fluctuations or active agents, [45][46][47][48][49] apart from a few recent papers, [50][51][52] very little is known about how elastic surfaces respond to non-equilibrium fluctuations, and this is an important problem given their relevance to biological and synthetic materials. [53][54][55] 2 Numerical model…”

The crumpling transition of active tethered membranes

“…More recently a significant effort has been put forward to understand the behavior of active fluid vesicles, [54][55][56][57][58] and it was recently suggested that the well known phenomenon of flickering observed in red-blood cells -the tethered counterpart to fluid membranes -breaks down the fluctuation-dissipation relation and can only be explained by the presence active, nonequilibrium forces. 59 It is therefore important to understand the behavior of tethered membranes under the presence of active forces, not only for their biological relevance but also because of their possible applications in materials engineering.…”