Aqueous two-phase systems (ATPSs) have been recognized for their applications in extraction, separation, purification, and enrichment of (bio)molecules and cells. Recently, their unique ability to ...create aqueous-aqueous interfaces through phase separation and the characteristics of these interfaces have created new opportunities in biomedical applications. In this review, we summarize recent progress in understanding the dynamics at aqueous-aqueous interfaces, and in developing interface-assisted design of artificial cells and cyto-mimetic materials, fabrication of cyto- and bio-compatible microparticles, cell micropatterning, 3D bioprinting, and microfluidic separation of cells and biomolecules. We also discuss the challenges and perspectives to leverage the unique characteristics of ATPSs and their interfaces in broader applications.
This review summarizes recent advances of aqueous two-phase systems (ATPSs), particularly their interfaces, with a focus on biomedical applications.
Digital loop‐mediated isothermal amplification (dLAMP) refers to compartmentalizing nucleic acids and LAMP reagents into a large number of individual partitions, such as microchambers and droplets. ...This compartmentalization enables dLAMP to be an excellent platform to quantify the absolute number of the target nucleic acids. Owing to its low requirement for instrumentation complexity, high specificity, and strong tolerance to inhibitors in the nucleic acid samples, dLAMP has been recognized as a simple and accurate technique to quantify pathogenic nucleic acid. Herein, the general process of dLAMP techniques is summarized, the current dLAMP techniques are categorized, and a comprehensive discussion on different types of dLAMP techniques is presented. Also, the challenges of the current dLAMP are illustrated together with the possible strategies to address these challenges. In the end, the future directions of the dLAMP developments, including multitarget detection, multisample detection, and processing nucleic acid extraction are outlined. With recently significant advances in dLAMP, this technology has the potential to see more widespread use beyond the laboratory in the future.
Herein, the concept of digital loop mediated isothermal amplification (dLAMP), which allows quantification of the absolute number of nucleic acids, is presented. The current dLAMP techniques, including their advantages and disadvantages are summarized. Furthermore, the challenges faced when applying dLAMP are discussed together with their potential solutions, followed by an outline of their future developments.
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Abstract
The synthetic pathways of life’s building blocks are envisaged to be through a series of complex prebiotic reactions and processes. However, the strategy to compartmentalize and concentrate ...biopolymers under prebiotic conditions remains elusive. Liquid-liquid phase separation is a mechanism by which membraneless organelles form inside cells, and has been hypothesized as a potential mechanism for prebiotic compartmentalization. Associative phase separation of oppositely charged species has been shown to partition RNA, but the strongly negative charge exhibited by RNA suggests that RNA-polycation interactions could inhibit RNA folding and its functioning inside the coacervates. Here, we present a prebiotically plausible pathway for non-associative phase separation within an evaporating all-aqueous sessile droplet. We quantitatively investigate the kinetic pathway of phase separation triggered by the non-uniform evaporation rate, together with the Marangoni flow-driven hydrodynamics inside the sessile droplet. With the ability to undergo liquid-liquid phase separation, the drying droplets provide a robust mechanism for formation of prebiotic membraneless compartments, as demonstrated by localization and storage of nucleic acids, in vitro transcription, as well as a three-fold enhancement of ribozyme activity. The compartmentalization mechanism illustrated in this model system is feasible on wet organophilic silica-rich surfaces during early molecular evolution.
Emerging wearable and implantable biodevices have been significantly revolutionizing the diagnosis and treatment of disease. However, the geometrical mismatch between tissues and biodevices remains a ...great challenge for achieving optimal performances and functionalities for biodevices. Shape-adaptable biodevices enabling active compliance with human body tissues offer promising opportunities for addressing the challenge through programming their geometries on demand. This article reviews the design principles and control strategies for shape-adaptable biodevices with programmable shapes and actively compliant capabilities, which have offered innovative diagnostic/therapeutic tools and facilitated a variety of wearable and implantable applications. The state-of-the-art progress in applications of shape-adaptable biodevices in the fields of smart textiles, wound care, healthcare monitoring, drug and cell delivery, tissue repair and regeneration, nerve stimulation and recording, and biopsy and surgery, is highlighted. Despite the remarkable advances already made, shape-adaptable biodevices still confront many challenges on the road toward the clinic, such as enhanced intelligence for actively sensing and operating in response to physiological environments. Next-generation paradigms will shed light on future directions for extending the breadth and performance of shape-adaptable biodevices for wearable and implantable applications.
Emerging wearable and implantable biodevices with shape-adaptable capabilities have been significantly revolutionizing the diagnosis and treatment of disease.
The Fourth Decade of Microfluidics Kong, Tiantian; Shum, Ho Cheung; Weitz, David A.
Small (Weinheim an der Bergstrasse, Germany),
03/2020, Volume:
16, Issue:
9
Journal Article
Peer reviewed
Open access
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•Achieve picoinjection free of any electricity inputs or the associated sophistication in device design.•Picoinjected volumes are stable and controlled.•Material (crystal and nanoparticle) syntheses ...are performed with distinct advantages using the proposed picoinjection.
Using droplet microfluidic picoinjection as a reactant dosing technique is of great importance in assembling artificial cells and performing multistep reactions. However, the utilization of electricity in the existing picoinjection complicates the device fabrication and operation, and compromises the bioactivity of the encapsulated bio-ingredients. In this work, we propose an electricity-free picoinjection technique as an alternative to address these issues. Specifically, by precisely controlling the pressures inside the microfluidic channel, we can inject one reactant into the flowing droplets that contain another reactant without applying the electric field. Furthermore, the dosed volumes can be tuned by controlling the value of external pressure or the ratio of flow rates between the continuous and droplet phases. To demonstrate the robustness of the proposed picoinjection, we apply it to synthesize crystals and nanoparticles. In the synthesis of crystals, the proposed picoinjection eliminates the problem of device fouling that occurs in the current reactant dosing devices. In the synthesis of nanoparticles, the proposed picoinjection generates nanoparticles that are highly monodispersed. As a result, this simplified picoinjection potentially extends the application of droplet microfluidics to investigate reaction dynamics or biochemical processes in cells. Besides, by eliminating the electricity, the proposed picoinjection avoids the usages of large equipment such as large power supplies or complicate devices, enhancing the accessibility of the proposed picoinjection.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Over the past two decades, advances in droplet-based microfluidics have facilitated new approaches to process and analyze samples with unprecedented levels of precision and throughput. A wide variety ...of applications has been inspired across multiple disciplines ranging from materials science to biology. Understanding the dynamics of droplets enables optimization of microfluidic operations and design of new techniques tailored to emerging demands. In this review, we discuss the underlying physics behind high-throughput generation and manipulation of droplets. We also summarize the applications in droplet-derived materials and droplet-based lab-on-a-chip biotechnology. In addition, we offer perspectives on future directions to realize wider use of droplet microfluidics in industrial production and biomedical analyses.
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.
We report a new method to display the minute fluctuations induced by syringe pumps on microfluidic flows by using a liquid-liquid system with an ultralow interfacial tension. We demonstrate that the ...stepper motor inside the pump is a source of fluctuations in microfluidic flows by comparing the frequencies of the ripples observed at the interface to that of the pulsation of the stepper motor. We also quantify the fluctuations induced at different flow rates, using syringes of different diameters, and using different syringe pumps with different advancing distances per step. Our work provides a way to predict the frequency of the fluctuation that the driving syringe pump induces on a microfluidic system and suggests that syringe pumps can be a source of fluctuations in microfluidic flows, thus contributing to the polydispersity of the resulting droplets.
Benefiting from the superior photophysical properties and low-cost crystalline substances, perovskites have emerged as a competitive photoactive semiconductor for optoelectronic devices such as solar ...cells (SCs), light-emitting diodes (LEDs), photodetectors (PDs), and lasers. These perovskite optoelectronics can realize the reciprocal conversion of light and electricity. The conversion efficiency, besides relying on the crystalline quality of perovskite materials, highly depends on the management of the incident and emitted photons throughout the utilization, extraction, emission, and modulation of light. Light management is even more crucial for perovskites given their direct band gap and high refractive index. Photonic structures with periodic features afford promising and efficient means to manage light through the interaction between media and photons. In this review, typical strategies of photon management
via
photonic structures are first discussed from the perspective of photo-physics, such as antireflection modes, scattering enhancement, resonance modes, and photonic crystals. Then the design and implementation progress of these photonic elements for high-index perovskite optoelectronics are systemically summarized. Finally, the proposals and guidelines for high-performance multifunctional perovskite optoelectronics are provided to expedite their practical applications.
Photonic structures afford robust means to manipulate photons through optical modes. The collective advantages of enhanced light trapping, light extraction, and colorful, semitransparent devices can be achieved by designing structured perovskite optoelectronics.
As one of the most widely distributed water resources, rainwater contains tremendous energy that cannot be effectively utilized by the conventional electromagnetic generators. Triboelectric ...nanogenerators (TENGs) represent a distributed method to convert trivial mechanical energy into electricity based on contact electrification. Benefiting from the large and replenishable contact interfaces in liquid–liquid systems, liquid–liquid TENG further promises efficient charge transfer. However, the limited understanding of liquid–liquid contact electrification has restricted its development. In this study, the mechanisms of contact electrification in various liquid–liquid systems is comprehensively investigated and thus a liquid–liquid TENG with optimized materials and structures to harvest energy from rainwater is demonstrated. The proposed liquid–liquid TENG generates a high charge density (3.63 µC L−1) with high output stability (crest factor ≈1.1) and long effective contact electrification time. Based on the direct current characteristics, energy harvested from rainwater can be fed directly to electronic devices and a self‐powered rainfall sensor can also be implemented. This study highlights the promise of all‐liquid systems in distributed green energy and passive sensors, offering a new perspective on self‐powered devices.
In this study, the mechanisms of contact electrification in various liquid–liquid systems is comprehensively investigated and thus a liquid–liquid triboelectric nanogenerator with optimized materials and structures to harvest energy from rainwater is demonstrated. It generates a high charge density (3.63 µC L−1) with high output stability (crest factor ≈1.1), highlighting the promise of all‐liquid systems in distributed green energy and passive sensors.
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