Development and future of droplet microfluidics
This review introduces the development of droplet microfluidics by explaining the physical mechanisms of droplet generation, discussing various approaches in manipulating droplets, and summarizing key applications in material science and biological analyses.
Advances in droplet digital polymerase chain reaction on microfluidic chips
This graphic includes droplet generation methods, thermal cycle strategies, signal counting approaches, and the applications in the fields of single-cell analysis, disease diagnosis, bacteria detection, and virus detection.
Communication
Fluorescence crosstalk reduction by modulated excitation-synchronous acquisition for multispectral analysis in high-throughput droplet microfluidics
A method to mitigate crosstalk and resolve droplet populations that are indistinguishable with conventional methods in high-throughput droplet screening for fluorescence barcoding applications.
Paper
High-throughput, combinatorial droplet generation by sequential spraying
Sequential spraying can be used to generate random mixtures, enabling interrogation of multicomponent concentration spaces.
Paper
3D-printed microfluidic–microwave device for droplet network formation and characterisation
A 3D-printed microwave–microfluidic device using a liquid metal resonator for droplet network formation and characterisation.
Polar coordinate active-matrix digital microfluidics for high-resolution concentration gradient generation
Advancing active-matrix digital microfluidics through polar coordinates for precise concentration gradients. Demonstrated with chip photography, concentration gradient solution demo, and efficiency comparison.
Paper
SeParate: multiway fluorescence-activated droplet sorting based on integration of serial and parallel triaging concepts
A novel platform, called SeParate, enabling accurate multiplex droplet sorting by integrating serial and parallel sorting principles for three model systems with increasing complexity and intra-subpopulation variation in fluorescence intensities.
Artificial intelligence-accelerated high-throughput screening of antibiotic combinations on a microfluidic combinatorial droplet system
An artificial intelligence-accelerated high-throughput combinatorial drug evaluation system was developed for rapid screening of antibiotic combinations and their dosage regimens.
Paper
Large scale microfluidic CRISPR screening for increased amylase secretion in yeast
Large scale perturbation of gene expression in yeast using CRISPR libraries, coupled with high-throughput screening using fluorescence-based sorting of microfluidic droplets, to identify genes important for increased α-amylase secretion.
Paper
Efficient full-length IgG secretion and sorting from single yeast clones in droplet picoreactors
We present a novel antibody screening platform based on antibody-secreting yeast cells encapsulated in droplets. This platform provides an antibody discovery process capable of screening large antibody libraries in their final soluble IgG format.
Flow cytometric printing of double emulsions into open droplet arrays
We describe a microfluidic approach to print double emulsions on demand in air, allowing each double emulsion droplet to be printed with the desired inner cores.
About this collection
Handpicked by our Associate Editor, Jean-Christophe Baret (University of Bordeaux), we are pleased to highlight select works on droplet microfluidics published in recent years. Read what he had to say below:
“Droplet-based microfluidics is the branch of microfluidics dealing with the production, manipulation, and analysis of dispersed micron-sized droplets carried out in an immiscible liquid.
This Editor's Choice collection on droplet-based microfluidics is a perfect occasion to highlight the contribution of the Lab on a Chip community in this field.
Droplet-based microfluidics kicked off in the early 2000s, leading to innovative approaches that are now mature at the industrial level. One example is droplet-digital PCR for molecular diagnostics (as reviewed by Lin et al). Many more examples in materials science and biotechnology are highlighted in the review by Shum, Weitz et al.
Droplet-based microfluidics combines the key principles of miniaturization, automation, and systems integration central to Lab on a Chip, which has made our journal a reference place for the community to share exciting developments.
First, as PDMS-based microfabrication techniques became mature enough to allow for the assembly of chips of increasing complexity, rapid turnover in terms of design, production, and testing proved key. In an emerging field where hydrodynamic principles governing flow behaviours are combined with external actuation mechanisms such as electric and magnetic fields, optical forces, thermal fields, and acoustics, the capacity to rapidly test systems was instrumental for the optimisation of devices. Nowadays, microfabrication makes use of 3D printing developments to further push the boundaries of microfabrication (Barrow et al.).
Second, the physical chemistry of dispersions and emulsions provided a reliable framework to understand the formation of droplets, their stability conditions, and the fundamentals of their actuation principles. Optimised formulations using fluorocarbon systems have also had a massive impact on the speed at which the technology developed. Yet, the environmental impact of PFAS now poses new challenges for the field, which will most likely drive further research and developments. The field now evolves towards off-chip operations (Cira et al.), open systems (Ma et al.), and new soft matter formulations compatible with standard lab systems, e.g., flow cytometers (Abate et al.).
Third, the increasing biological need for high-throughput and miniaturization technologies created innovation pressure and stimulated technology developers to produce systems compatible with new methodologies for improved sensing capabilities, enhanced throughput, and higher levels of integration. The collection highlights how key applications already advanced to the industrial level for biochemical analysis and cell selection (Steinmetz et al.) or antibody selection (Mottet et al.) continuously evolve, and how sensing and analytical performance (Merten et al.) or selection capabilities (Lammertyn et al.) can be further enhanced. The throughput of measurements in droplet-based microfluidics makes it a perfect match to combine with artificial intelligence approaches to further accelerate discovery rates in biotechnology (Huang et al.)!
Beyond this somewhat subjective selection of highlights, the collection gathers here a set of top publications in the field published in Lab on a Chip over the past two years.
We hope that you will find new sources of inspiration from these reports and look forward to reading about your latest advances soon in a paper in Lab on a Chip!"