Combining sensors and actuators with electrowetting-on-dielectric (EWOD): advanced digital microfluidic systems for biomedical applications

Abstract

The concept of digital microfluidics (DMF) enables highly flexible and precise droplet manipulation at a picoliter scale, making DMF a promising approach to realize integrated, miniaturized “lab-on-a-chip” (LOC) systems for...

Integrated Microfluidics for Single‐Cell Separation and On‐Chip Analysis: Novel Applications and Recent Advances

“…• Precise positioning and targeted manipulation of droplets leveraging microwells, magnetophoresis, DMF or microvalves [ 124,141–143,204 ]…”

“…• Label-free, contact-free separation • Controlled confinement of single cells in welldefined microenvironments [125,127,201] • No cross-talk between droplets [125,127,201] • Minimal sample and reagent usage, therefore cost reduction [125,127] • Suitable for a variety of assays, including genomic, transcriptomic, proteomic, and metabolic studies [125] • Fast reaction times and real-time detection [127,131] • High-throughput [126,127] • Cell encapsulation into droplets nonselective and based on Poisson statistics, which might lead to a high number of empty droplets [131,132,189] • Droplet size crucial in cell viability, nutrient replenishment and waste removal in droplets are limited [136,201] • Culturing of single adherent cells challenging [136,201,264] • Potential for droplet coalescence or instability, affecting assay results [265,266] • Application of image recognition techniques for selective droplet manipulation [131] • In-droplet solution exchange for nutrient supply and waste removal [133,134] • Gentle manipulation of large droplets without breakage for improved cell viability for longer periods [135] • Cell attachment on microgels prior to droplet encapsulation to establish adherent cell cultures in droplets [140] • Precise positioning and targeted manipulation of droplets leveraging microwells, magnetophoresis, DMF or microvalves [124,[141][142][143]204] NiFe-based magnetic microtweezer to trap and extract magnetic particles from a continuous stream of droplets (see Section 2.2.4 for droplet microfluidics). [57] The platform exhibited exceptional performance i...…”

“…The most common actuation principle is electrowetting on dielectric, which causes a reversible wettability shift induced by an electric charge on a dielectric surface. [124] Tong et al have recently reviewed system-level and chip-scale integration of DMF devices, as well as hybrid actuation strategies, including digital-to-channel and channel-to-digital interfaces. [124] Droplet-based microfluidic technologies and their application to single-cell workflows offer significant advantages such as high throughput, parallelization possibilities, controlled confinement of single cells, and significant reagent cost reduction.…”

“…[124] Tong et al have recently reviewed system-level and chip-scale integration of DMF devices, as well as hybrid actuation strategies, including digital-to-channel and channel-to-digital interfaces. [124] Droplet-based microfluidic technologies and their application to single-cell workflows offer significant advantages such as high throughput, parallelization possibilities, controlled confinement of single cells, and significant reagent cost reduction. [125][126][127] Furthermore, droplets provide an ideal microenvironment for conducting a variety of biological assays, offering precise spatial and temporal resolution.…”

Semi-analytical modeling of electro-strictive behavior in dielectric elastomer tube actuators

“…Soft actuators and sensors represent a groundbreaking field in modern engineering, with the ability to respond to various stimuli, including temperature [1,2], chemical triggers [3,4], and electric signals [5][6][7][8][9]. Dielectric actuators have emerged as a crucial player, driving many recent engineering marvels.…”