Tailored Combinatorial Microcompartments through the Self‐Organization of Microobjects: Assembly, Characterization, and Cell Studies

Abstract

An ew concept enables the generation of cell microenvironments by microobject assembly at an water/air interface.Asthe orientation of 30 mmsized polymer cubes and their capillary force assembly are controlled by the surface wettability,w hich in turn can be modulated by coating the initially exposed surfaces with gold and self-assembled monolayers,u nique niches in closely packed arrays of cubes with vertex up orientation can be realized. The random assembly of distinctly different cubes,p refunctionalized or surface-structured exclusively on their top surface,f acilitates the parallel generation of different microenvironments in ac ombinatorial manner,w hichp aves the wayt of uture systematic structureproperty relationship studies with cells.

Chains of cubic colloids at fluid–fluid interfaces

“…The scenario experimentally found in Refs. [23,24] represents, at the same time, a confirmation and an extension of the theoretical predictions previously presented in Refs. [25,26].…”

“…While hydrophilic cubes with a small θ ∼ 0 give rise to square close-packed aggregates, by increasing θ first linear aggregates and finally hexagonal aggregates are observed. Cases of coexistence between linear and hexagonal aggregates have also been reported [23,24].…”

“…Among the several shapes studied so far, cubic particles have been proven to form 2D structures with striking features. In recent experiments [23,24] for example, polystyrene cubes with 30 µm edge length have been reported to self-assemble at a water-air interface into three distinct structures, namely square close-packed, linear, and hexagonal structures. Furthermore, the relative stability of these three phases has been shown to strongly depend on their wettability, which is specified by the so-called Young contact angle θ [13].…”

“…a "face up" configuration in the square closepacked structure, an "edge up" configuration in the linear structure, and a "vertex up" configuration in the hexagonal structure, the authors of Refs. [23,24] have argued that the formation of each 2D structure could be caused by a different kind of deformation field induced by the cubes at the interface. In particular these authors have proposed that cubes adsorbed in the "face up", "edge up", and "vertex up" configurations would induce monopolar, quadrupolar and hexapolar deformation fields, respectively.…”

Optocapillarity-driven assembly and reconfiguration of liquid crystal polymer actuators

“…rogrammable assembly of small objects on the liquid surface is of paramount significance for numerous perspectives, ranging from bottom-up fabrication of functional materials and devices [1][2][3][4][5][6] to a fundamental understanding of biological systems [6][7][8] . Capillarity, which induces interface distortion and generates capillary forces to attract or repel objects nearby 9 , provides a powerful means to assemble objects with a variety of geometries across a wide range of length scales 10,11 .…”