Open millifluidics based on powder-encased channels

Abstract

Millifluidics, the manipulation of liquid flow in millimeter-sized channels, has been a revolutionary concept in chemical processing and engineering. The solid channels that contain the liquids, though, are not flexible in their design and modification, and prevent contact with the external environment. All-liquid constructs, on the other hand, while flexible and open, are imbedded in a liquid environment. Here, we provide a route to circumvent these limitations by encasing the liquids in a hydrophobic powder in air that jams on the surface, containing and isolating flowing fluids, offering flexibility and adaptability in design, as manifest in the ability to reconfigure, graft, and segment the constructs. Along with the open nature of these powder-contained channels that allow arbitrary connections/disconnections and substance addition/extraction, numerous applications can be opened in the biological, chemical, and material arenas.

Rod‐Shaped Liquid Plasticine as Cuttable Minireactor for Photodynamic Therapy of Tumors

“…Because of interfacial jamming, an LP can be easily cut by a hydrophobic tool into pieces without leaking its inner liquid. [18,19,23,37,48] In the experiment here, we cut a group of identical rod-shaped LPs with each into pre-defined piece numbers, by running a plastic pipette across the LP body (Figure 5a). The surface NPs rearranged to cover the newly exposed surfaces, and the areal particle density decreased gradually with the number of segmentation times, relieving the surface jamming such that the daughter LPs from multiple segmentations tended to exhibit rounded profiles (Figure 5b).…”

“…Recently, increasing attention has been paid to miniature liquid reactors played by particle-encased liquid constructs, including spherical "liquid marbles (LMs)" [15][16][17] and complexly shaped "liquid plasticines" (LPs), [18] as they are able to circumvent the limitations of solid reactors based on their peculiar properties of openness, cuttability, reconfigurability, among others. [19,20] Attractive achievements have been made using these liquid reactors in many areas including 3D cell culture, [21,22] protein separation and analysis, [23] surface enhanced Raman spectroscopy, [24,25] chemical synthesis, [26] CO 2 capture, [27] and sensors. [28,29] The PDT area has been also accessed in which a LM minireactor was demonstrated to surpass the commonly used petri dish in the resultant efficacy of PDT, owing to the greater specific surface area that led to the use of more light.…”

Quantitative Analysis of a Pilot Transwell Barrier Model with Automated Sampling and Mathematical Modeling

“…Advances in millifluidics [32,33] allow the automatization of standard cell culture procedures, including periodic sample collection under sterile conditions [34][35][36]. This approach can obtain enough samples from regular transwell barrier cultures to determine their time-resolved transport kinetics comparable to the data obtainable from microfluidic Franz chambers.…”