A multilayer lateral-flow microfluidic device for particle separation

Integration of acoustic, optical, and electrical methods in picoliter droplet microfluidics for rare particles enrichment

Rare particle enrichment plays a pivotal role in advancing numerous scientific research areas and industrial processes. Traditional enrichment methods encounter obstacles such as low efficiency, high cost, and complexity. Acoustic focusing, optical fiber detection, and electrical manipulation have shown potential in microfluidics for particle manipulation and analysis. This study pioneers the integration of the acoustic, optical, and electrical units to overcome the traditional limitations. The cooperative dynamics of acoustic and flow focusing are explored. The optical fibers with an enhanced detection algorithm greatly boost optical detection sensitivity. Furthermore, the droplet charging to enhance the tip charging phenomenon is complemented and validated. The detection and sorting accuracy of enriching large-size H22 cells reached 99.8% and 99.3%, respectively, with the target cell concentration increased by nearly 86-fold. Our work significantly enhances detection sensitivity and particle manipulation accuracy, ultimately offering a robust and reliable solution for generating droplets to enrich rare particles.

Recent progress, challenges, and prospects of fully integrated mobile and wearable point-of-care testing systems for self-testing

The rapid growth of research in the areas of chemical and biochemical sensors, lab-on-a-chip, mobile technology, and wearable electronics offers an unprecedented opportunity in the development of mobile and wearable point-of-care testing (POCT) systems for self-testing. Successful implementation of such POCT technologies leads to minimal user intervention during operation to reduce user errors; user-friendly, easy-to-use and simple detection platforms; high diagnostic sensitivity and specificity; immediate clinical assessment; and low manufacturing and consumables costs. In this review, we discuss recent developments in the field of highly integrated mobile and wearable POCT systems. In particular, aspects of sample handling platforms, recognition elements and sensing methods, and new materials for signal transducers and powering devices for integration into mobile or wearable POCT systems will be highlighted. We also summarize current challenges and future prospects for providing personal healthcare with sample-in result-out mobile and wearable POCT.

Mass-producible microporous silicon membranes for specific leukocyte subset isolation, immunophenotyping, and personalized immunomodulatory drug screening in vitro

Widespread commercial and clinical adaptation of biomedical microfluidic technology has been limited in large part due to the lack of mass producibility of polydimethylsiloxane (PDMS) and glass-based devices commonly as reported in the literature. Here, we present a batch-fabricated, robust, and mass-producible immunophenotyping microfluidic device using silicon micromachining processes. Our Si and glass-based microfluidic device, named the silicon microfluidic immunophenotyping assay (SiMIPA), consists of a highly porous (∼40%) silicon membrane that can selectively separate microparticles below a certain size threshold. The device is capable of isolating and stimulating specific leukocyte populations, and allows for measuring their secretion of cell signaling proteins by means of a no-wash homogeneous chemiluminescence-based immunoassay. The high manufacturing throughput (∼170 devices per wafer) makes a large quantity of SiMIPA chips readily available for clinically relevant applications, which normally require large dataset acquisitions for statistical accuracy. With 30 SiMIPA chips, we performed in vitro immunomodulatory drug screening on isolated leukocyte subsets, yielding 5 data points at 6 drug concentrations. Furthermore, the excellent structural integrity of the device allowed for samples and reagents to be loaded using a micropipette, greatly simplifying the experimental protocol.