Many forms of memory can be stored in the materials around us. Examples are hysteresis magnets, aging and rejuvenation glasses, shape alloys, echoes spin systems capillary waves. Once material is fully equilibrated, system's initial conditions or previous history completely lost. Memory thus intimately connected to out-of-equilibrium behavior. This paper reviews examples where specific inputs condensed-matter then retrieved by appropriate protocols. It describes some common principles...

Using an electrical method and high-speed imaging, we probe drop coalescence down to 10 ns after the drops touch. By varying liquid viscosity over two decades, conclude that, at a sufficiently low approach velocity where deformation is not present, coalesce with unexpectedly late crossover time between regime dominated by viscous one inertial effects. We argue that crossover, accounted for in theory, can be explained appropriate choice of length scales present flow geometry.

Drop coalescence is central to diverse processes involving dispersions of drops in industrial, engineering and scientific realms. During coalescence, two first touch then merge as the liquid neck connecting them grows from initially microscopic scales a size comparable drop diameters. The curvature interface infinite at point where make contact, flows that ensue coalesce are intimately coupled this singularity dynamics. Conventionally, process has been thought have just dynamical regimes:...

Wrinkle patterns in compressed thin sheets are ubiquitous nature and technology, from the furrows on our foreheads to crinkly plant leaves, ripples plastic-wrapped objects protein film milk. The current understanding of an elementary descriptor wrinkles--their wavelength--is restricted deformations that parallel, spatially uniform, nearly planar. However, most naturally occurring wrinkles do not satisfy these stipulations. Here we present a scheme quantitatively explains wrinkle wavelength...

A system with multiple transient memories can remember a set of inputs but subsequently forgets almost all them, even as they are continually applied. If noise is added, the store indefinitely. The phenomenon has recently been predicted for cyclically sheared non-Brownian suspensions. Here we present experiments on such suspensions, finding behavior consistent and showing how be stabilized by noise.

The coalescence of liquid drops has conventionally been thought to have just two regimes when the are brought together slowly in vacuum or air: a viscous regime corresponding Stokes-flow limit and later inertially dominated regime. Recent work [Proc. Natl. Acad. Sci. 109, 6857 (2012)] found that cannot be reached early moments coalescence, because inertia neglected then. Instead, described by an ``inertially limited viscous'' regime, where surface tension, inertia, forces all balance....

The Young's modulus of polymer thin films was measured from bulk that are micrometers in thickness down to having a ∼6 nm, which is less than the radius gyration, Rg. A simple, noninvasive technique same geometry, i.e., wrinkling free-floating film on water surface with droplet film, used determine over this very large range thicknesses. Unlike solid substrate, there no in-plane stresses exerted by underlying liquid substrate except at boundary film. Using recent theoretical developments...

Many complex fluids rely on surfactants to contain, protect, or isolate liquid drops in an immiscible continuous phase. Thin elastic sheets can wrap a spontaneous process driven by capillary forces. For encapsulation be practically viable, rapid, continuous, and scalable is essential. We exploit the fast dynamics of droplet impact achieve wrapping oil droplets ultrathin polymer films water Despite violence splashing events, robustly yields wrappings that are optimally shaped maximize...

Small groups of hysteretic elements can explain how a system returns to previous state only after multiple driving cycles.

Many objects in nature and industry are wrapped a thin sheet to enhance their chemical, mechanical, or optical properties. There similarly variety of methods for wrapping, from pressing film onto hard substrate, using capillary forces spontaneously wrap droplets, inflating closed membrane. Each these settings raises challenging nonlinear problems involving the geometry mechanics sheet, often context resolving geometric incompatibility between two surfaces. Here we review recent progress this...

Solids are rigid, which means that when left undisturbed, their structures nearly static. It follows these depend on history—but it is surprising they hold readable memories of past events. Here, we review the research has recently flourished around mechanical memory formation, beginning with amorphous solids’ various deformation and mesoscopic models based particle rearrangements. We describe how concepts apply to a much wider range solids glassy matter, bridge physical computing in...

Multiple transient memories, originally discovered in charge-density-wave conductors, are a remarkable and initially counterintuitive example of how system can store information about its driving. In this class learn multiple driving inputs, nearly all which eventually forgotten despite their continual input. If sufficient noise is present, the regains plasticity so that it continue to new memories indefinitely. Recently, Keim Nagel [Phys. Rev. Lett. 107, 010603 (2011)] showed could be...

Particle suspensions, present in many natural and industrial settings, typically contain aggregates or other microstructures that can complicate macroscopic flow behaviors damage processing equipment. Recent work found applying uniform periodic shear near a critical transition reduce fluctuations the particle concentration across all length scales, leading to hyperuniform state. However, this strategy for homogenization requires fine tuning of strain amplitude. Here we show model sedimenting...

Predicting the large-amplitude deformations of thin elastic sheets is difficult due to complications self contact, geometric nonlinearities, and a multitude low-lying energy states. We study simple two-dimensional setting where an annular polymer sheet floating on air-water interface subjected different tensions inner outer rims. The folds wrinkles into many distinct morphologies that break axisymmetry. These states can be understood within recent approach for determining gross shape...

Positronium (Ps)-He scattering presents one of the few opportunities for both theory and experiment to tackle fundamental interactions Ps with ordinary matter. Below dissociation energy $6.8\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$, experimental theoretical work has struggled find agreement on strength this interaction as measured by momentum-transfer cross section $({\ensuremath{\sigma}}_{m})$. Here, we present utilizing Doppler broadening technique an age-momentum correlation apparatus. This...

Significance Thin films readily buckle to relax compression, creating wrinkle patterns that may cover large portions of the solid. Predicting arrangement wrinkles in general settings is a major challenge affects our understanding stresses and deformations textiles, biological tissues, synthetic skins. We identify mesoscale structure arises from incompatibility uniformly spaced spatially varying director, unraveling an organizing principle with analogs liquid crystalline superconducting states matter.

Many materials that are out of equilibrium can ‘learn’ one or more inputs repeatedly applied. Yet, a common framework for understanding such memories is lacking. Here, we construct minimal representations cyclic memory behaviours as directed graphs, and simple physically motivated models produce the same graph structures. We show how model worn grass between park benches multiple transient memories—a behaviour previously observed in dilute suspensions particles charge-density-wave...

Thin elastic solids are easily deformed into a myriad of three-dimensional shapes, which may contain sharp localized structures as in crumpled candy wrapper, or have smooth and diffuse features like the undulating edge flower. Anticipating controlling these morphologies is crucial to variety applications involving textiles, synthetic skins, inflatable structures. Here we show that "wrinkle-to-crumple" transition, previously observed specific settings, ubiquitous response for confined sheets....

Thin elastic films can spontaneously attach to liquid interfaces, offering a platform for tailoring their physical, chemical, and optical properties. Current understanding of the elastocapillarity thin is based primarily on studies planar sheets. We show that curved shells be used manipulate interfaces in qualitatively different ways. elucidate regime where an ultrathin shell with vanishing bending rigidity imposes its own rest shape surface, using experiment theory. Conceptually, pressure...

Using experiments, simulations, and theory, we map out the remarkably rich mechanical response of a floating polymer film to indentation.

A buckled sheet offers a reservoir of material that can be unfurled at later time. For sufficiently thin yet stiff materials, this geometric process has striking mechanical feature: when the slack runs out, locks to further extension. Here, we establish simple route tunable locking material: system with an interval where it is freely deformable under given deformation mode, and endpoints changed continuously over wide range. We demonstrate type response in formed into cylindrical shell...