Diffusiophoresis-enhanced Turing patterns

Abstract

Turing patterns are fundamental in biophysics, emerging from short-range activation and long-range inhibition processes. However, their paradigm is based on diffusive transport processes that yield patterns with shallower gradients than those observed in nature. A complete physical description of this discrepancy remains unknown. We propose a solution to this phenomenon by investigating the role of diffusiophoresis, which is the propulsion of colloids by a chemical gradient, in Turing patterns. Diffusiophoresis enables robust patterning of colloidal particles with substantially finer length scales than the accompanying chemical Turing patterns. A scaling analysis and a comparison to recent experiments indicate that chromatophores, ubiquitous in biological pattern formation, are likely diffusiophoretic and the colloidal Péclet number controls the pattern enhancement. This discovery suggests that important features of biological pattern formation can be explained with a universal mechanism that is quantified straightforwardly from the fundamental physics of colloids.

Periodic pattern formation during embryonic development

“…Recent technical advancements such as fluorescence correlation spectroscopy for in vivo measurement of diffusion coefficients and ligand interactions/degradation of morphogens [ 90–92 ], as well as atomic force microscopy for assessing mechanical properties of tissues undergoing patterning [ 9 , 93 ], have enabled quantification of these parameters, and thus a more accurate dissection of the underlying patterning processes. Furthermore, mathematical models incorporating factors such as tissue growth [ 94 ], mechano-chemical feedback loops [ 95 ], and diffusiophoresis [ 96 ] into classical Turing RD systems, continue to be developed in an effort to more accurately reflect biological patterns.…”

4D printing for biomedical applications

“…228–230 Recent findings, however, suggest that the fingerprint patterning is better described by Turing reaction-diffusion mechanisms during developmental processes, 231 the same mechanism that determines hair follicle spacing, 232 lends cheetah its spots, 233 or an Ornate Boxfish its hexagon/stripe patterns. 234 Patterned surfaces governed by Turing reaction-diffusion mechanisms will represent a new direction in 4D surface morphing.…”

Diffusiophoresis: a novel transport mechanism - fundamentals, applications, and future opportunities

“…Similar to its role in laundry (Shin et al, 2018), diffusiophoresis can be used for cleaning membranes or removing particles from electrodes. Additionally, by triggering reaction-diffusion instabilities (Alessio and Gupta, 2023a), Turing patterns may allow one to sense external chemical concentration. Another possibility for sensing applications is to use passive and active diffusiophoresis simultaneously to create shape-shifting patterns in real-time for detection of harmful chemicals.…”

“…Recent research on diffusiophoresis has demonstrated that it is crucial for a broad range of phenomena, such as exclusion zone formation near membranes (Florea et al, 2014), removal of contaminants during laundry (Shin et al, 2018), formation of patterns on vertebrate skins (Alessio and Gupta, 2023a), and possibly even migration patterns in humans Alessio and Gupta (2023b). In fact chemotaxis, i.e., movement of microorganisms upon sensing gradients in chemoattractants, is essentially a subclass for diffusiophoresis, and is mathematically identical to diffusiophoresis (Alessio and Gupta, 2023a;Alessio and Gupta, 2023b;Chu et al, 2021). From an application standpoint, diffusiophoresis has been used for creating living crystals (Palacci et al, 2013), micromotor machines (Aubret et al, 2018), membrane-less water filters (Shin et al, 2017c) and low-cost zetasizers (Shin et al, 2017a).…”