An alcohol (pentanol) droplet exhibits spontaneous motion on an aqueous solution, driven by a solutal Marangoni effect. We found that the droplets mode of is controlled its volume. A with volume less than 0.1 microl shows irregular translational motion, whereas intermediate-sized 0.1-200 show vectorial motion. When above 300 microl, splits into smaller drops. These experimental results regarding selection are interpreted in terms wave-number depending

We review nonliving systems that behave like living matter by focusing on nonlinearity to enhance autonomy and the response of system.

We theoretically derive the amplitude equations for a self-propelled droplet driven by Marangoni flow. As advective flow surface tension gradient is enhanced, stationary state becomes unstable and starts to move. The velocity of determined from cubic nonlinear term in equations. obtained critical point characteristic are well supported numerical simulations.

Quantitative information on the parameters associated with self-propelled objects would enhance potential of this research field; for example, finding a realistic way to develop functional object and quantitative understanding mechanism self-motion. We therefore estimated five main parameters, including driving force, camphor boat as simple that spontaneously moves water due difference in surface tension. The experimental results mathematical model indicated generated force 4.2 μN, which...

We propose a framework for the spontaneous motion of droplet coupled with internal dynamic patterns generated in reaction-diffusion system. The spatiotemporal order chemical reaction gives rise to inhomogeneous surface tension and results self-propulsion driven by surrounding flow due Marangoni effect. Numerical calculations together theoretical fields at low Reynolds number reproduce well experimental obtained using Belousov-Zhabotinsky medium.

Zonula occludens-1 (ZO-1) is a scaffolding protein of tight junctions, which seal adjacent epithelial cells, that also expressed in adherens junctions. The distribution pattern ZO-1 differs among stratified squamous epithelia, including between skin and oral buccal mucosa. However, the causes for this difference, mechanisms underlying spatial regulation, have yet to be elucidated. In study, we showed turnover proliferation are associated with epithelia. We tried verify regulation by...

The generation of convective flow by a chemical wave was studied experimentally on mm-sized droplet Belousov–Zhabotinsky (BZ) reaction medium. A propagating causes transient increase in interfacial tension, and this local change tension induces convection. observed profile reproduced with numerical simulation introducing the to modified Navier–Stokes equation coupled kinetic equation; Oregonator. We also periodic motion BZ floating an oil phase. Such is attributed rhythmic tension. discussed...

We investigate a simple experimental system using candles; stable combustion is seen when single candle burns, while oscillatory three candles burn together. If we consider set of as component oscillator, two oscillators, that is, sets candles, can couple with each other, resulting in both in-phase and antiphase synchronization depending on the distance between sets. The mathematical model indicates induced by lack oxygen around burning point. Furthermore, suggest thermal radiation may be an...

We demonstrated mode-switching of self-motion coupled with diffusion molecules at a solid/liquid interface. A camphor boat moved spontaneously on water and the mode depended setup boat. When disk was connected to center larger plastic plate, intermittent motion (alternating between rest rapid motion) observed. position changed from one its edges, period decreased, continuous motion. The features this were qualitatively reproduced by numerical calculation using mathematical model that...

Chemical control of the spontaneous motion a reactive oil droplet moving on glass substrate under an aqueous phase is reported. Experimental results show that self-motion confined acid-treated surface. The transient behavior oil-droplet also observed with high-speed video camera. A mathematical model incorporates effect surface charge built based experimental observation motion. numerical simulation this reproduced essential features concerning confinement within certain chemical territory...

The self-motion of a camphor disk on water was investigated both experimentally and theoretically. When the moved along one-dimensional chamber, convective flow observed around magnitude convection decreased with an increase in velocity motion. exhibited characteristic motion that depended shape base chamber. nature reproduced by numerical simulation included surface tension layer as driving force Marangoni induced difference disk.

The coupling between deformation and motion in a self-propelled system has attracted broader interest. In the present study, we consider an elliptic camphor particle for investigating effect of shape on spontaneous motion. It is concluded that symmetric spatial distribution molecules at water surface becomes unstable first direction short axis, which induces disk this direction. Experimental results also support theoretical analysis. From results, suggest when supplies surface-active to...

We consider a rotor made of two camphor disks glued below the ends plastic stripe. The are floating on water surface and stripe does not touch surface. system can rotate around vertical axis located at center dissipate molecules. driving momentum comes from nonuniformity tension resulting inhomogeneous concentration molecules disks. investigate stationary angular velocity as function radius $\ell$. For large $\ell$ decreases for increasing At specific value reaches its maximum and, short it...

Surface-active molecules supplied from a particle fixed at the water surface create spatial gradient of molecule concentration, resulting in Marangoni convection. Convective flow transports far particle, enhancing diffusion. We analytically derive effective diffusion coefficient associated with convection rolls. The estimated is consistent our numerical results and apparent measured experiments.

Epithelia consist of proliferating and differentiating cells that often display patterned arrangements. However, the mechanism regulating these spatial arrangements remains unclear. Here, we show cell–cell adhesion dictates multicellular patterning in stratified epithelia. When cultured keratinocytes, a type epithelial cell skin, are subjected to starvation, they spontaneously develop pattern characterized by areas high low density. Pharmacological knockout experiments adherens junctions...

We investigated the Marangoni flow around a camphor disk on water with addition of sodium dodecyl sulfate (SDS). The velocity decreased an increase in concentration SDS aqueous phase, and was hardly observed critical micelle (cmc), because reduced driving force flow. However, increased further SDS. Thus, is maximally inhibited cmc In this paper, we concluded that regeneration originates from dissolution rate into solution.

The motion of a self-propelled particle is affected by its surroundings, such as boundaries or external fields. In this paper, we investigated the bifurcation camphor grain, simple actual system, confined in one-dimensional finite region. A grain exhibits oscillatory remains at rest around center position water channel, depending on length channel and resistance coefficient. mathematical model including boundary effect analytically reduced to an ordinary differential equation. Linear...

Abstract The self-propelled motion with deformation of micrometer-sized soft matter in water has potential application not only for underwater carriers or probes very narrow spaces but also understanding cell locomotion terms non-equilibrium physics. As far as we know, there have been no reports about mimicking amoeboid underwater. Here, report an artificial molecular system oil droplets exhibiting initial experimental model. We describe the heterogeneity a deformable droplet aqueous and...

Abstract The design, construction and control of artificial self-organized systems modelled on dynamical behaviours living are important issues in biologically inspired engineering. Such usually based complex reaction dynamics far from equilibrium; therefore, the non-equilibrium conditions is required. Here we report a droplet open-reactor system, fusion fission, that achieves over chemical fluxes into/out reactor for reactions equilibrium. We mathematically reveal mechanism formulated as...

Collective motions are the spontaneous emergence of ordered movement in living systems. Various constructive approaches have been attempted toward understanding mechanism. However, few studies on motion induced by biomimetic artificial systems based molecular conversions. In this study, we report an system oil droplets surfactant solutions, wherein collective and pattern formation occur concurrently, using conversion photoresponsive surfactants. Assembly/dispersion multiple...