The mixing of confined liquids is a central yet challenging operation in miniaturized devices. Microfluidic mixing is usually achieved with passive mixers that are robust but poorly flexible, or active mixers that offer dynamic control but mainly rely on electrical or mechanical transducers, which increase the fragility, cost, and complexity of the device. Here, we describe the first remote and reversible control of microfluidic mixing triggered by a light illumination simply provided by an external LED illumination device. The approach is based on the light-induced generation of water microdroplets acting as reversible stirrers of two continuous oil phase flows containing samples to be mixed. We demonstrate many cycles of reversible photoinduced transitions between a nonmixing behavior and full homogenization of the two oil phases. The method is cheap, portable, and adaptable to many device configurations, thus constituting an essential brick for the generation of future all-optofluidic chip.
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http://dx.doi.org/10.1021/ja311837r | DOI Listing |
Nat Mater
January 2025
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
Cells use 'active' energy-consuming motor and filament protein networks to control micrometre-scale transport and fluid flows. Biological active materials could be used in dynamically programmable devices that achieve spatial and temporal resolution that exceeds current microfluidic technologies. However, reconstituted motor-microtubule systems generate chaotic flows and cannot be directly harnessed for engineering applications.
View Article and Find Full Text PDFAnal Chim Acta
March 2025
Holosensor Medical Technology Ltd, Room 12, No. 1798, Zhonghuayuan West Road, Yushan Town, Suzhou, 215000, China; Department of Veterinary Medicine, University of Cambridge, Cambridge, UK. Electronic address:
Rapid and sensitive protein detection methods are of benefit to clinical diagnosis, pathological mechanism research, and infection prevention. However, routine protein detection technologies, such as enzyme-linked immunosorbent assay and Western blot, suffer from low sensitivity, poor quantification and labourious operation. Herein, we developed a fully automated protein analysis system to conduct fast protein quantification at the single molecular level.
View Article and Find Full Text PDFLangmuir
January 2025
School of Chemistry, Key Centre for Polymers and Colloids, The University of Sydney, Sydney, New South Wales 2006, Australia.
Polymer Janus nanoparticles with one hard cross-linked polystyrene lobe and one soft film-forming poly(methyl methacrylate--butyl acrylate) lobe were synthesized by reversible addition-fragmentation chain transfer (RAFT)-mediated emulsion polymerization. The Janus nanoparticles adsorbed to oil/water and air/water interfaces, where the soft lobes coalesced, forming films of thickness between 25 and 250 nm; droplets of silicone oil could be stably encapsulated in polymer in this way. When prepared by mechanical mixing without additives, capsules of diameter 5-500 μm could be prepared, and with additives and application of heat, capsules of diameter around 5 μm were achieved, even with highly viscous silicone oil (20,000 cSt).
View Article and Find Full Text PDFJ Control Release
January 2025
Bioprocessing Technology Institute (BTI), Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #06-01 Centros, Singapore 138668, Republic of Singapore. Electronic address:
mRNA-loaded lipid nanoparticles (mRNA-LNPs) hold great potential for disease treatment and prevention. LNPs are normally made from four lipids including ionizable lipid, helper lipid, cholesterol, and PEGylated lipid (PEG-lipid). Although PEG-lipid has the lowest content, it plays a crucial role in the effective delivery of mRNA-LNPs.
View Article and Find Full Text PDFLab Chip
January 2025
Department of Biotechnology and Bioengineering, Izmir Institute of Technology, Izmir 35430, Turkiye.
Centrifugation is crucial for size and density-based sample separation, but low-volume or delicate samples suffer from loss and impurity issues during repeated spins. We introduce the "Spinochip", a novel microfluidic system utilizing centrifugal forces for efficient filling of dead-end microfluidic channels. The Spinochip enables versatile fluid manipulation with a single reservoir for both inlet and outlet functions.
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