Harnessing liquid-in-liquid printing and micropatterned substrates to fabricate 3-dimensional all-liquid fluidic devices

Abstract

Systems comprised of immiscible liquids held in non-equilibrium shapes by the interfacial assembly and jamming of nanoparticle−polymer surfactants have significant potential to advance catalysis, chemical separations, energy storage and conversion. Spatially directing functionality within them and coupling processes in both phases remains a challenge. Here, we exploit nanoclay−polymer surfactant assemblies at an oil−water interface to produce a semi-permeable membrane between the liquids, and from them all-liquid fluidic devices with bespoke properties. Flow channels are fabricated using micropatterned 2D substrates and liquid-in-liquid 3D printing. The anionic walls of the device can be functionalized with cationic small molecules, enzymes, and colloidal nanocrystal catalysts. Multi-step chemical transformations can be conducted within the channels under flow, as can selective mass transport across the liquid−liquid interface for in-line separations. These all-liquid systems become automated using pumps, detectors, and control systems, revealing a latent ability for chemical logic and learning.

Perspective: Ferromagnetic Liquids

“…Low viscosity liquids enable the rapid fabrication of liquid constructs with complex interconnected structures. Molded channels have been employed for selective mass transportation based on modifying the walls with cationic or anionic molecules, enzymes and colloidal nanocrystal catalysts [11]. A multi-responsive structured liquid system can be used to dynamically control droplet reactors [10].…”

“…Consequently, the interface can be effectively functionalized by the segregation of molecular surfactants [2,3], polyelectrolytes [4,5], biomaterials [6], liquid crystals [7,8] and micro/nanoparticles [1,9], to the interface endowing the interface with the inherent characteristics and functionalities of these materials. Provided the binding energy of the particles to the interface is sufficiently high, immiscible liquid phases can be emulsified and stabilized against coalescence, affording compartmentalization that enables mass or ion transport for drug delivery, or fluidic reactors [10,11]. Depending on the inherent properties of the particles, the interfaces can be made responsive to magnetic [12,13], optical [14][15][16], electric or mechanical fields, or chemical and biological stimuli [17][18][19].…”

Self‐Assembly of Nanoparticles in 2D and 3D: Recent Advances and Future Trends

“…Multiple emulsions have great potential for application in food science as a means to reduce fat content or for controlled encapsulation and release of active ingredients . The structured liquid paradigm can be harnessed in liquid‐in‐liquid printing and micropatterned substrates to fabricate 3D all‐liquid fluidic devices that are infinitely reconfigurable and endowed with spatially programmable functions . These chemical systems of arbitrary complexity can be utilized in multi‐step chemical transformations, chemical separations, and chemical logic and learning.…”

Inner Surface Design of Functional Microchannels for Microscale Flow Control

“…Moreover, they also realized fluid pumping through changing the Laplace pressure and hydrostatic pressure. Most recently, Helms and co‐workers reported the fabrication of microchannels with liquid walls through liquid‐in‐liquid printing and micropatterning techniques . After adding appropriate volume of the nanoclay dispersion on patterned superhydrophilic area, a solution with surfactants, silicone oil, or hexadecane was overlaid on the surface, which resulted in the interfacial self‐assembly of nanoclay–polymer surfactants at the oil–water interface and formation of an elastic semipermeable membrane wall.…”