Liquid Wells as Self‐Healing, Functional Analogues to Solid Vessels

Abstract

Liquids are traditionally handled and stored in solid vessels. Solid walls are not functional, adaptive, or self‐repairing, and are difficult to remove and re‐form. Liquid walls can overcome these limitations, but cannot form free‐standing 3D walls. Herein, a liquid analogue of a well, termed a “liquid well” is introduced. Water tethered to a surface with hydrophobic–hydrophilic core–shell patterns forms stable liquid walls capable of containing another immiscible fluid, similar to fluid confinement by solid walls. Liquid wells with different liquids, volumes, and shapes are prepared and investigated by confocal and Raman microscopy. The confinement of various low‐surface‐tension liquids (LSTLs) on surfaces by liquid wells can compete with or be complementary to existing confinement strategies using perfluorinated surfaces, for example, in terms of the shape and height of the confined LSTLs. Liquid wells show unique properties arising from their liquid aggregate state: they are self‐healing, dynamic, and functional, that is, not restricted to a passive confining role. Water walls can be easily removed and re‐formed, making them interesting as sacrificial templates. This is demonstrated in a process termed water‐templated polymerization (WTP). Numerical phase‐field model simulations are performed to scrutinize the conditions required for the formation of stable liquid wells.

Feedback-controlled topological reconfiguration of molecular assemblies for programming supramolecular structures

“…Common strategies to control liquids include patterning surfaces, embedding water into a matrix of viscous oil, manipulating water-oil emulsions in microfluidic devices, and holding aqueous channels by immiscible magnetic liquid barriers. [42][43][44][45][46] Our G-quartet-based transient supramolecular hydrogels with good adaptivity and dissipative properties are promising transient wells for gel-templated polymerization. Rheological studies (Fig.…”

Structured-Liquid Batteries

“…Initially, an interdigitated array with prototypical thin fingers connected to two large reservoirs was used (Figure S11). However, the Laplace pressure drove the liquids from the fingers to the reservoirs. , Consequently, an interdigitated array with thick fingers was designed and fabricated (Figure S9B). The two electrode designs shared a similar surface area (8.04 vs 7.97 cm 2 ), but the boundaries between the current collectors were different (12.7 vs 120 mm).…”

“…Here, we harness the interfacial assembly of polyelectrolytes to fabricate structured-liquid batteries on hydrophobic substrates with patterned hydrophilic electrodes (Figure ). By controlling the geometry and surface chemistry of current collectors, , we can prescribe an interface between aqueous biphasic anolytes and catholytes deposited onto the electrodes (Figure B). Once the interface is formed, polyanions, e.g., poly­(sodium 4-styrenesulfonate), PSS–Na, dissolved in the anolyte form an ionically conductive coacervate membrane with polycations, e.g., poly­(diallyldimethylammonium chloride), PDADMA–Cl, dissolved in the catholyte. , We also leverage ion pairing between polyelectrolytes and oppositely charged charged active materials to mitigate the rate of active-material crossover between phases, allowing the device to be cycled over hundreds of hours. − The power delivered by such devices is on the order of that found in biological circuits and sensors, demarking future usecases based on that complementarity.…”

“…Here, we harness the interfacial assembly of polyelectrolytes to fabricate structured-liquid batteries on hydrophobic substrates with patterned hydrophilic electrodes (Figure 1). 19 By controlling the geometry and surface chemistry of current collectors, 21,22 we can prescribe an interface between aqueous biphasic anolytes and catholytes deposited onto the electrodes (Figure 1B). Once the interface is formed, polyanions, e.g., poly(sodium 4-styrenesulfonate), PSS−Na, dissolved in the anolyte form an ionically conductive coacervate membrane with polycations, e.g., poly(diallyldimethylammonium chloride), PDADMA−Cl, dissolved in the catholyte.…”

Functional Blood–Brain Barrier Model with Tight Connected Minitissue by Liquid Substrates Culture

“…The shape of the liquid surface was governed by the Young–Laplace equation; that is, the potential energy was minimized under the constraint of the conservation of each liquid volume, resulting in stereoscopic spheroids of cells. [ 26 ] Due to the regularity and symmetry of their shape, the stereoscopic spherical cells spontaneously self‐assembled to form the hexagonal closest packing structure. Cells cultured by the LSC method had closer intercellular spacing, which contributes to more efficient intercellular communication.…”