Mosaic Patterned Surfaces toward Generating Hardly‐Volatile Capsular Droplet Arrays for High‐Precision Droplet‐Based Storage and Detection

Abstract

Precise detection involving droplets based on functional surfaces is promising for the parallelization and miniaturization of platforms and is significant in epidemic investigation, analyte recognition, environmental simulation, combinatorial chemistry, etc. However, a challenging and considerable task is obtaining mutually independent droplet arrays without cross‐contamination and simultaneously avoiding droplet evaporation‐caused quick reagent loss, inaccuracy, and failure. Herein, a strategy to generate mutually independent and hardly‐volatile capsular droplet arrays using innovative mosaic patterned surfaces is developed. The evaporation suppression of the capsular droplet arrays is 1712 times higher than the naked droplet. The high evaporation suppression of the capsular droplet arrays on the surfaces is attributed to synergistic blocking of the upper oil and bottom mosaic gasproof layer. The scale‐up of the capsular droplet arrays, the flexibility in shape, size, component (including aqueous, colloidal, acid, and alkali solutions), liquid volume, and the high‐precision hazardous substance testing proves the concept's high compatibility and practicability. The mutually independent capsular droplet arrays with amazingly high evaporation suppression are essential for the new generation of high‐performance open‐surface microfluidic chips used in COVID‐19 diagnosis and investigation, primary screening, in vitro enzyme reactions, environmental monitoring, nanomaterial synthesis, etc.

Droplet transportation on photosensitive lubricant-impregnated slippery surfaces in response to the light induced Marangoni effect and asymmetrical wetting ridges

“…Besides, excellent biocompatibility and avoidance of cross contamination are also required in the fields of PCR and bio-analysis. [17][18][19] In this regard, the optical strategy shows the most promising potential in non-contact remote control. The droplet transportation can be flexibly controlled by an as-designed photothermal substrate upon irradiation.…”

Light-Controlled Particle Enrichment Patterns in Droplets

“…Precise manipulation of fluids/particles has been considerably advanced and accompanied by but not limited to microfluidics development for clinical diagnosis and self-assembly of sensors. − Up to this date, several manipulation techniques have been developed based on various mechanisms, such as acoustics, , magnetism, , electric fields, , and optofluidics. , Although they are promising, acoustic and electrowetting methods require complex and costly chip fabrication. The application of magnetism methods is limited by magnetic particles.…”

Thermocapillary flow‐induced core release from double‐emulsion droplets in microchannels

“…Meanwhile, the direct manipulation of the droplets within single emulsions (SEs) can prevent cross‐contamination during reactions and facilitate high‐throughput microfluidics operations 7,8 . Furthermore, double emulsions (DEs) are made up of immiscible liquids composed of droplets within droplets, and therefore have a unique core–shell structure that dramatically expands the range of their applications in droplet‐based microfluidics 9,10 . For example, the outer droplet (i.e., shell) of a DE can prevent substances within the inner droplet (i.e., core) from contacting and reacting with the continuous phase during transport.…”