Droplet最新文献

Liquid biopsy, a noninvasive technique to obtain tumor information from body fluids, is an emerging technology for cancer diagnosis, prognosis, and monitoring, providing crucial support for the realization of precision medicine. The main biomarkers of liquid biopsy include circulating tumor cells, circulating tumor DNA, microRNA, and circulating tumor exosomes. Traditional liquid biopsy detection methods include flow cytometry, immunoassay, polymerase chain reaction (PCR)-based methods, and next-generation sequencing (NGS)-based methods, which are time-consuming, labor-intensive, and cannot reflect cell heterogeneity. Droplet-based microfluidics with high throughput, low contamination, high sensitivity, and single-cell/single-molecule/single-exosome analysis capabilities have shown great potential in the field of liquid biopsy. This review aims to summarize the recent development in droplet-based microfluidics in liquid biopsy for cancer diagnosis.

Inside Back Cover: The cover image is based on the Review Article Hydrodynamic metamaterials: Principles, experiments, and applications by Chen et al.

This cover highlights diverse hydrodynamic metamaterials with versatile applications. These materials show great potential in drag reduction, advanced drug delivery, microfluidic device design, and tissue engineering. The review explores various design principles and the wide-ranging possibilities offered by hydrodynamic metamaterials in these fields. (DOI: 10.1002/dro2.79)

Front Cover: The cover image is based on the Review Article New insights into the interactions between two-dimensional ice and two-dimensional materials by Thi et al.

Controlling water droplet to two-dimensional (2D) ice transition by temperature at interface with the 2D layer materials enable multiple processes including cleaning surface, achieving high-yield instant transfer, and reducing friction for tribological applications. (DOI:10.1002/dro2.88)

Inside Front Cover: The cover image is based on the Research Article Liquid encapsulation in a freezing sessile drop by Lyu et al.

This paper demonstrates that the environmental medium, particularly one with high thermal conductivity such as a liquid, has nonnegligible heat exchange with both the drop and the substrate, which changes the final outcome of a freezing drop. This study highlights the importance of considering the properties of the environmental medium and provides novel strategies to manipulate a freezing drop. (DOI: 10.1002/dro2.90)

Back Cover: The cover image is based on the Review Article Building block copolymer particles via self-assembly within a droplet by Zhang et al.

The self-assembly of block copolymers within emulsion droplets is a flexible strategy for the preparation of polymer particles. This review systematically delves into the multiple mechanisms that drive BCP self-assembly within emulsion droplets, discusses various applications of BCP particles across multiple disciplines, and presents an overview of the current challenges and future directions for BCP emulsion self-assembly. (DOI: 10.1002/dro2.81)

Frontispiece: The cover image is based on the Research Article Two modes of contact-time reduction in the impact of particle-coated droplets on superhydrophobic surfaces by Lathia et al.

Micro-nano hydrophobic particle-coated droplets, known as liquid marbles (LM), can reduce impact contact time. This paper identifies two distinct modes of contact time reduction, namely, adhesion mode and fragmentation mode which are responsible for up to 65% reduction as compared to a bare droplet impact. (DOI: 10.1002/dro2.89)

Hydrodynamic metamaterials, a nascent research field, possess immense potential for fluid flow manipulation. With engineered structure design, they offer unparalleled control over fluid behavior beyond the capabilities of conventional methods. In this review, we focus on hydrodynamic metamaterials and provide a comprehensive overview of the current state of this research field. We start by introducing basic theories and principles of hydrodynamic metamaterials and then illustrate the different functions of hydrodynamic metamaterials that have been realized in porous medium flow and Hele-Shaw flow. Moreover, we also demonstrate the multifunctional metamaterials that have been developed in hydrodynamics. Some research progresses are highlighted due to their promising applications, including drag reduction, microfluidic manipulation, and biological tissue coculture. The review concludes by identifying major challenges and proposing research directions for the future.

The self-assembly of block copolymers (BCPs) within emulsion droplets is a flexible strategy for the preparation of polymer particles. This strategy permits the fine-tuning of shapes, internal structures, and surface nanostructures of the polymer particles, thus allowing many applications. Although some literature has reviewed the BCP preparation via self-assembly within a droplet, a comprehensive summary including in-depth understanding, controllable preparation, and application is lacked. In this review, we systematically delve into the multiple mechanisms that drive BCP self-assembly within emulsion droplets, such as commensurability effects for minimizing total free energy, interfacial instability, organized spontaneous emulsification, phase separation of multiple components, and entropy effects between BCPs and nanoparticles. Additionally, a strategy combining selective cross-linking and disassembly can further generate Janus particles featuring unique structures. Next, various applications across multiple disciplines are discussed, including drug delivery, display, biomedical imaging, macromolecular separation, and fuel cells. Finally, we present an overview of the current challenges and future directions for BCP emulsion self-assembly, covering mechanism investigation, molecular design, stability control, and application exploration. We anticipate deeper understanding, more varieties, enhanced performance, and broader applications can be achieved with BCP emulsion self-assembly after addressing the challenge.

During the solidification of a sessile drop, the effect of heat exchange from the gaseous environmental medium is generally ignored. However, by combining experimental observations, direct numerical simulations, and a theoretical model, we have demonstrated that the environmental medium, particularly one with high thermal conductivity such as a liquid, has nonnegligible heat exchange with both the drop and the substrate, leading to accelerated cooling of the outer surface of the sessile drop. Consequently, it causes alterations in the geometry of the freezing front and ultimately results in the formation of a solidified shell that encloses the drop. Furthermore, the encapsulated liquid continues to solidify, which induces volume change and consequently changes the final outcome of the freezing process. This study highlights the importance of considering the properties of the environmental medium and provides novel strategies to manipulate the freezing rate and reshape the morphology of the solidified drop.

Water is one of the most essential substances for life on Earth and plays a vital role in both natural and technological processes. Recently, there has been growing interest in studying the behavior of water molecules in confined spaces, particularly in low-dimensional materials and structures. Regardless of whether it is in the form of gas, liquid, or solid, water can interact and form interfaces with many low-dimensional structures. Given the current controversial understanding of two-dimensional (2D) ice and the increasing interplay between water/ice and 2D materials such as graphene and transition-metal dichalcogenides, we provide a brief overview of recent progresses on the interfaces of 2D ice and 2D van der Waals layered materials. This review highlights their potential contributions to the breakthroughs in tribology, membrane technology, nanofluidic, and nanodevice applications. Of particular interest is the recent discovery of ultrahigh lubricity between 2D ice and 2D layered materials, as well as the ability to modulate the surface adhesion between layers. These findings have the potential to enable new technological advances in both electronics and various industries. Meanwhile, this rapidly evolving field presents its own challenges, and we also discuss future directions for exploiting the interactions between 2D ice and 2D layered materials.