Droplet最新文献_第6页

Solidification characteristics of two-dimensional water droplets 二维水滴的凝固特性

IF 9.1

Droplet Pub Date : 2025-09-12 DOI: 10.1002/dro2.70031

Mengjie Song, Runmiao Gao, Chaobin Dang, Keke Shao, Long Zhang

{"title":"Solidification characteristics of two-dimensional water droplets","authors":"Mengjie Song, Runmiao Gao, Chaobin Dang, Keke Shao, Long Zhang","doi":"10.1002/dro2.70031","DOIUrl":"https://doi.org/10.1002/dro2.70031","url":null,"abstract":"Frost and ice are ubiquitous in nature and industry, and sometimes cause problems. The solidification of water droplets is in the early stage of frosting and icing and has attracted extensive research interest. However, due to physical occlusion, solidification characteristics inside a droplet are always unclear. In this study, Hele‒Shaw cells were used to produce cross-sectional slices of water droplets deposited on hydrophilic and hydrophobic surfaces, referred to as two-dimensional droplets. The solidification characteristics of these droplets were investigated at micrometer spatial and millisecond temporal scales. Results show that the maximum dendrite growth velocity reached 0.45 m/s during the recalescence stage. Using the side‑view freezing front height from a three‑dimensional droplet as a proxy for the true front height introduces errors ranging from ‒35% to +45%. For a ‒30°C substrate, the maximum longitudinal temperature difference within the droplet reached 7.3°C. Additionally, micro-scale trapped air bubbles with equivalent diameters ranging from 18 to 78 µm switch their growth mode from spheroidal to longitudinal approximately 250 ms into the freezing stage, corresponding to about 17% of the total growing time. These findings provide new insight into frosting and icing physics and may inform enhanced defrosting and de‑icing strategies.","PeriodicalId":100381,"journal":{"name":"Droplet","volume":"4 4","pages":""},"PeriodicalIF":9.1,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dro2.70031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145385073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Understanding pathogen transmission on inanimate surfaces: Insights from respiratory fluid droplet composition and drying dynamics 了解病原体在无生命表面的传播：从呼吸道液滴组成和干燥动力学的见解

IF 9.1

Droplet Pub Date : 2025-09-11 DOI: 10.1002/dro2.70029

Abdur Rasheed, Kirti Parmar, Jason Joy Poopady, Siddhant Jain, Dipshikha Chakravortty, Saptarshi Basu

{"title":"Understanding pathogen transmission on inanimate surfaces: Insights from respiratory fluid droplet composition and drying dynamics","authors":"Abdur Rasheed, Kirti Parmar, Jason Joy Poopady, Siddhant Jain, Dipshikha Chakravortty, Saptarshi Basu","doi":"10.1002/dro2.70029","DOIUrl":"https://doi.org/10.1002/dro2.70029","url":null,"abstract":"This study investigates how pathogen-laden respiratory droplets transfer diseases via inanimate surfaces. Respiratory fluid ejections containing pathogens pose a significant health threat, especially in high-traffic areas such as hospitals, public transport, restaurants, and schools. When these droplets dry on surfaces, they form deposits that can transfer pathogens to healthy individuals through contact and can be ingested via the oral or nasal route. The study examined the effects of varying salt and mucin concentrations in respiratory fluid droplets containing Pseudomonas aeruginosa. Results showed that P. aeruginosa viability increased 10-fold at elevated mucin concentrations, while changes in salt concentration had minimal impact. Adhesive properties of the deposits were analyzed using atomic force spectroscopy and scotch tape test. Pathogen transfer from the deposit to a fingerprint patterned model thumb at different relative humidity (RH) levels was assessed using confocal microscopy, showing significant pathogen transfer at elevated RH. Out of 106 CFU/mL pathogens in deposits, 17%‒38% are potentially transferable, with most of the transfer occurring from the droplet's edge deposits. The study demonstrated that the combined variation in salt and mucin concentrations significantly influences the evaporation, flow, and precipitation dynamics of droplets. These changes, in turn, affect the solutal deposition and distribution of pathogens within the droplet, ultimately altering the survivability and transmissibility of the pathogen.","PeriodicalId":100381,"journal":{"name":"Droplet","volume":"4 4","pages":""},"PeriodicalIF":9.1,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dro2.70029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145385074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bioinspired superwetting SERS substrate based on femtosecond laser processing: Principles, methods, and applications 基于飞秒激光加工的生物启发超湿SERS衬底：原理、方法和应用

IF 9.1

Droplet Pub Date : 2025-09-11 DOI: 10.1002/dro2.70022

Jinglan Huo, Xubo Huang, Jiangfeng Zhu

{"title":"Bioinspired superwetting SERS substrate based on femtosecond laser processing: Principles, methods, and applications","authors":"Jinglan Huo, Xubo Huang, Jiangfeng Zhu","doi":"10.1002/dro2.70022","DOIUrl":"https://doi.org/10.1002/dro2.70022","url":null,"abstract":"The growing demand for surface-enhanced Raman scattering sensors in biochemical detection, environmental monitoring, microfluidics, and other fields has promoted the development of highly sensitive and stable substrates. Femtosecond laser-fabricated surfaces with controlled wettability, unique micro/nanostructure designs, and tunable extreme wetting properties can significantly enhance the signal amplification and reproducibility of surface-enhanced Raman scattering techniques. In this review, we offer a comprehensive overview of recent advancements in surface-enhanced Raman scattering techniques based on superwetting surfaces fabricated by femtosecond laser processing, including fully superhydrophobic surfaces, hybrid wettability surfaces, and visual localization surfaces. The main research areas, such as pattern optimization, dynamic measurements, hot spot enhancement, and stability improvement, are highlighted. We also summarize the practical applications of surface-enhanced Raman scattering in chemical detection, microfluidic control, medical diagnosis, and food safety evaluation. Finally, the current challenges and limitations in the development of femtosecond laser-processed superwetting substrates for surface-enhanced Raman scattering are described.","PeriodicalId":100381,"journal":{"name":"Droplet","volume":"4 4","pages":""},"PeriodicalIF":9.1,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dro2.70022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145385072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Rapid detection and quantification of ultralow-concentration nanoparticles based on nanopore array blockage 基于纳米孔阵列阻断的超低浓度纳米颗粒快速检测与定量

IF 9.1

Droplet Pub Date : 2025-08-04 DOI: 10.1002/dro2.70020

Rami Yazbeck, Jiayi Xu, Yiding Zhong, Yixin Xu, Liangwei Zheng, Bernie Xu, Chuanhua Duan

{"title":"Rapid detection and quantification of ultralow-concentration nanoparticles based on nanopore array blockage","authors":"Rami Yazbeck, Jiayi Xu, Yiding Zhong, Yixin Xu, Liangwei Zheng, Bernie Xu, Chuanhua Duan","doi":"10.1002/dro2.70020","DOIUrl":"https://doi.org/10.1002/dro2.70020","url":null,"abstract":"Rapid and accurate detection of ultralow-concentration nanoparticles is crucial for applications ranging from medical diagnosis to water quality monitoring, yet remains challenging for current laser-based and light-scattering methods. While nanoparticle-translocation-based nanopore sensing offers single-particle resolution, conventional single-nanopore resistive pulse sensing approaches suffer from low capture frequency, transient signals, and clogging issues, limiting their effectiveness at extremely low concentrations. Here, we present a novel nanopore array blockage-based sensing strategy for the rapid detection and quantification of ultralow-concentration nanoparticles. Using hydraulic force, nanoparticles are driven through an array of subnanoparticle-sized pores, and optical microscopy monitors blockage progression to obtain quantitative concentration data. Our results demonstrate a linear correlation between the initial blockage rate and nanoparticle concentration, enabling the detection of fluorescent nanoparticles down to 0.5 aM (300 particles/mL) within 5 min—a three-order-of-magnitude improvement in sensitivity over previous nanopore-based methods. Additionally, our approach can leverage fluorescent nanoparticles as probes to detect unlabeled nanoparticles and contaminants at similarly low concentrations. This strategy provides a robust, efficient, and rapid platform for ultrasensitive nanoparticle detection, with promising applications in biomedical research, environmental monitoring, and industrial quality control.","PeriodicalId":100381,"journal":{"name":"Droplet","volume":"4 4","pages":""},"PeriodicalIF":9.1,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dro2.70020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145385106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bubble pinch-off on biphilic and superhydrophobic surfaces 双疏和超疏水表面上的气泡夹断

IF 9.1

Droplet Pub Date : 2025-08-04 DOI: 10.1002/dro2.70021

Hangjian Ling, Isaac Rodriguez, Foram S. Fanasia, Paitynn Boutin

{"title":"Bubble pinch-off on biphilic and superhydrophobic surfaces","authors":"Hangjian Ling, Isaac Rodriguez, Foram S. Fanasia, Paitynn Boutin","doi":"10.1002/dro2.70021","DOIUrl":"https://doi.org/10.1002/dro2.70021","url":null,"abstract":"In this work, we experimentally measured the pinch-off of a gas bubble on a biphilic surface, which consisted of an inner circular superhydrophobic region and an outer hydrophilic region. The superhydrophobic region had a radius of RSH varying from 2.8 to 19.0 mm, where the large RSH modeled an infinitely large superhydrophobic surface. We found that during the pinch-off, the contact line had two different behaviors: for small RSH, the contact line was fixed at the boundary of superhydrophobic and hydrophilic regions, and the contact angle gradually increased; in contrast, for large RSH, the contact angle was fixed, and the contact line shrank toward the bubble center. Furthermore, we found that regardless of bubble size and contact line behavior, the minimum neck radius collapsed onto a single curve after proper normalizations and followed a power–law relation where the exponent was close to that for bubble pinch-off from a nozzle. The local surface shapes near the neck were self-similar. Our results suggest that the surface wettability has a negligible impact on the dynamics of pinch-off, which is primarily driven by liquid inertia. Our findings improve the fundamental understanding of bubble pinch-off on complex surfaces.","PeriodicalId":100381,"journal":{"name":"Droplet","volume":"4 4","pages":""},"PeriodicalIF":9.1,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dro2.70021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145385107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An electrocyte-inspired moisture-driven electricity generator for self-sustained water electrolysis 一种以电解电池为灵感的湿驱动发电机，用于自我持续的水电解

IF 9.1

Droplet Pub Date : 2025-07-24 DOI: 10.1002/dro2.70018

Quanmao Wei, Wenna Ge, Chenguang Lu, Zichao Yuan, Lei Yi, Yuhui Zhao, Shile Feng, Yu Sun, Lei Zhao, Yahua Liu

{"title":"An electrocyte-inspired moisture-driven electricity generator for self-sustained water electrolysis","authors":"Quanmao Wei, Wenna Ge, Chenguang Lu, Zichao Yuan, Lei Yi, Yuhui Zhao, Shile Feng, Yu Sun, Lei Zhao, Yahua Liu","doi":"10.1002/dro2.70018","DOIUrl":"https://doi.org/10.1002/dro2.70018","url":null,"abstract":"Harvesting electricity from ubiquitous moisture offers the promise of clean power for self-sustained systems. Despite extensive efforts, achieving high-power electricity generation remains challenging. Existing studies mimicking electric eels’ electrogenesis to enhance their electrical performance focused on the two-membrane structure that linearly adds up the voltage, but their current output was either transient or limited to microamperes, because of the large resistance for ion diffusing across material interfaces. Here, we report an electrocyte-inspired moisture-driven electricity generator (EMEG) made from an interphase-mediated Janus film. The continuous interphase significantly alleviates the ion migration resistance, boosting the current output to 150 µA and sustaining the voltage of 0.8 V continuously for more than 1000 h. We also show that integrated EMEGs were easily assembled to self-powered smart watch for emergency rescue. Furthermore, the integrated EMEGs achieved self-sustained and moisture-powered water splitting with a steady hydrogen production. Our results provide a rational for bio-inspired designs toward green and sustained power generation.","PeriodicalId":100381,"journal":{"name":"Droplet","volume":"4 4","pages":""},"PeriodicalIF":9.1,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dro2.70018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145385092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biomimetic chloroplasts: Two-phase microfluidic platforms with selective permeability for artificial photosynthesis 仿生叶绿体：用于人工光合作用的两相微流控平台

IF 9.1

Droplet Pub Date : 2025-07-24 DOI: 10.1002/dro2.70019

Guanxiong Wang, Meiying Hong, Chonghui Yang, Menghan Yang, Gaozhen Zhao, Haixia Liu, Rui Shen, Siping Wang, Xuming Zhang, Xiaowen Huang, Yaolei Wang

{"title":"Biomimetic chloroplasts: Two-phase microfluidic platforms with selective permeability for artificial photosynthesis","authors":"Guanxiong Wang, Meiying Hong, Chonghui Yang, Menghan Yang, Gaozhen Zhao, Haixia Liu, Rui Shen, Siping Wang, Xuming Zhang, Xiaowen Huang, Yaolei Wang","doi":"10.1002/dro2.70019","DOIUrl":"https://doi.org/10.1002/dro2.70019","url":null,"abstract":"The development of biomimetic chloroplasts offers significant potential in addressing global energy and environmental challenges. Traditional droplet-based models are limited by transmembrane transport inefficiencies, leading to the accumulation of aqueous products that severely hinder reaction performance. In this work, we present a biomimetic chloroplast system that integrates light-dependent and light-independent reactions, reaction compartments, and selectively permeable interfaces, fabricated using a biphasic microfluidic platform. The permeable interface facilitates continuous substrate–product exchange, mitigating product inhibition and side reactions, thus enhancing reaction efficiency. Furthermore, a quartz spiral tube was engineered to amplify Dean vortex effects, improving mass transfer. This system exhibited a nicotinamide adenine dinucleotide regeneration efficiency during light-dependent reactions that was 5.52 times higher than that of conventional slurry reactors. In the light-independent reaction, the energy conversion efficiency for the transformation of α-ketoglutaric acid to L-glutamic acid reached 1.45 times that of natural photosynthesis. As the first comprehensive integration of photosynthetic processes within artificial chloroplasts, this work combines biological mechanisms with engineered components to establish a transformative platform for efficient energy conversion and directional biosynthesis. This breakthrough advances the field of photocatalysis and bioinspired technologies, with wide-reaching implications for sustainable energy and synthetic biology applications.","PeriodicalId":100381,"journal":{"name":"Droplet","volume":"4 4","pages":""},"PeriodicalIF":9.1,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dro2.70019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145385093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inside Back Cover, Volume 4, Number 3, July 2025 封底内，第四卷，第三期，2025年7月

Droplet Pub Date : 2025-07-21 DOI: 10.1002/dro2.70026

Ying Zhou, Wenchang Zhao, Shiyu Wang, Yanhong Li, Shuxian Tang, Yutong Zheng, Pingan Zhu

引用次数: 0

Back Cover, Volume 4, Number 3, July 2025 封底，第四卷，第三期，2025年7月

Droplet Pub Date : 2025-07-21 DOI: 10.1002/dro2.70023

Yuxin Song, Zuohua Huang, Chenglong Tang

引用次数: 0

Inside Front Cover, Volume 4, Number 3, July 2025 2025年7月第4卷第3期封面内页

Droplet Pub Date : 2025-07-21 DOI: 10.1002/dro2.70027

Mengchen Cui, Hongyue Chen, Xiuxing Tang, Yutong Guo, Xianyu Nong, Changlin Ding, Zhijun Wang, Xin Gao, Duyang Zang

引用次数: 0