Droplet Pub Date : 2024-01-01 DOI: 10.1002/dro2.91

Yang Li, Xuezhi Qin, Yawei Feng, Yuxin Song, Zhiran Yi, Huanxi Zheng, Peiyang Zhou, Chenyang Wu, Siyan Yang, Lili Wang, Pingan Zhu, Wanghuai Xu, Zuankai Wang

{"title":"A droplet-based electricity generator incorporating Kelvin water dropper with ultrahigh instantaneous power density","authors":"Yang Li, Xuezhi Qin, Yawei Feng, Yuxin Song, Zhiran Yi, Huanxi Zheng, Peiyang Zhou, Chenyang Wu, Siyan Yang, Lili Wang, Pingan Zhu, Wanghuai Xu, Zuankai Wang","doi":"10.1002/dro2.91","DOIUrl":"10.1002/dro2.91","url":null,"abstract":"Harvesting renewable water energy in various formats such as raindrops, waves, and evaporation is one of the key strategies for achieving global carbon neutrality. The recent decade has witnessed rapid advancement of the droplet-based electricity generator (DEG) with a continuous leap in the instantaneous output power density from 50 W/m2 to several kW/m2. Despite this, further pushing the upper limit of the output performance of DEG is still constrained by low surface charge density and long precharging time. Here, we report a DEG incorporating the Kelvin water dropper (K-DEG) that can generate an ultrahigh instantaneous power density of 105 W/m2 upon one droplet impinging. In this design, the Kelvin water dropper continuously replenishes the high density of surface charges on DEG, while DEG fully releases these surface charges into electric output. K-DEG with such a high output can directly light five 6-W commercial lamps and even charge a cellphone by using falling droplets.","PeriodicalId":100381,"journal":{"name":"Droplet","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dro2.91","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139392676","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

Acoustic micro-beam vortex generator for flow actuation inside droplets 用于液滴内部流动驱动的声学微束涡流发生器

Droplet Pub Date : 2024-01-01 DOI: 10.1002/dro2.96

Diego Sánchez-Saldaña, Maria Fernandino, Carlos A. Dorao

{"title":"Acoustic micro-beam vortex generator for flow actuation inside droplets","authors":"Diego Sánchez-Saldaña, Maria Fernandino, Carlos A. Dorao","doi":"10.1002/dro2.96","DOIUrl":"10.1002/dro2.96","url":null,"abstract":"Controlling acoustic streaming inside a droplet has excellent potential for enabling fluid and particle operations such as mixing, separation, and aggregation in various applications. Most concepts for generating surface acoustic waves are based on the placement of an interdigitated transducer at the side of a droplet, thus externally acting on the droplet. In this case, the flow structure inside the droplet is controlled by the relatively large scale of the interdigitated transducer compared to the droplet, thus limiting the local control of the flow. One possibility to overcome this drawback is to reduce the size of the actuator such that a highly focused ultrasound transducer can induce localized acoustic streaming in space. Here, we introduce a micro-spiral interdigitated transducer smaller than a droplet size that can generate micro-size vortices inside the droplet. This step enables a new way of controlling the flow inside the droplet, facilitating mixing, separation, aggregation, and patterning of particles. We study the characteristics of the acoustic streaming and the potential application of the flow for the separation and patterning of particles. The simplicity of the concept provides in-droplet particle manipulation toolsets for many applications such as biosensing, microbiology, and point-of-care devices.","PeriodicalId":100381,"journal":{"name":"Droplet","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dro2.96","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139457213","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

Digital twin of a droplet microarray platform: Evaporation behavior for multiple droplets on patterned chips for cell culture 液滴微阵列平台的数字双胞胎：用于细胞培养的图案化芯片上多个液滴的蒸发行为

Droplet Pub Date : 2024-01-01 DOI: 10.1002/dro2.94

Yanchen Wu, Joaquin E. Urrutia Gomez, Hongmin Zhang, Fei Wang, Pavel A. Levkin, Anna A. Popova, Britta Nestler

{"title":"Digital twin of a droplet microarray platform: Evaporation behavior for multiple droplets on patterned chips for cell culture","authors":"Yanchen Wu, Joaquin E. Urrutia Gomez, Hongmin Zhang, Fei Wang, Pavel A. Levkin, Anna A. Popova, Britta Nestler","doi":"10.1002/dro2.94","DOIUrl":"10.1002/dro2.94","url":null,"abstract":"Precise control of the evaporation of multiple droplets on patterned surfaces is crucial in many technological applications, such as anti-icing, coating, and high-throughput assays. Yet, the complex evaporation process of multiple droplets on well-defined patterned surfaces is still poorly understood. Herein, we develop a digital twin system for real-time monitoring of key processes on a droplet microarray (DMA), which is essential for parallelization and automation of the operations for cell culture. Specifically, we investigate the evaporation of multiple nanoliter droplets under different conditions via experiments and numerical simulations. We demonstrate that the evaporation rate is not only affected by the environmental humidity and temperature but is also strongly linked to the droplet distribution on the patterned surfaces, being significantly reduced when the droplets are densely distributed. Furthermore, we propose a theoretical method to aid in the experimental detection of volumes and pH variation of evaporating droplets on patterned substrates. This versatile and practical strategy allows us to achieve active maneuvering of the collective evaporation of droplets on a DMA, which provides essential implications for a wide range of applications including cell culture, heat management, microreactors, biochips, and so on.","PeriodicalId":100381,"journal":{"name":"Droplet","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dro2.94","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139458165","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

Chemical reaction in a liquid–liquid phase-separated multiple droplet: Synchronization of color change dynamics with droplet movement 液-液相分离的多液滴中的化学反应：颜色变化动态与液滴运动的同步性

Droplet Pub Date : 2024-01-01 DOI: 10.1002/dro2.93

Kenta Goto, Kyoka Nakanishi, Fumito Tani, Satoru Tokuda

引用次数: 0

Recent advances in droplet-based microfluidics in liquid biopsy for cancer diagnosis 基于液滴的微流控技术在用于癌症诊断的液体活检中的最新进展

Droplet Pub Date : 2024-01-01 DOI: 10.1002/dro2.92

Jingyu Shi, Yu Zhang, Yadi Fan, Yi Liu, Mo Yang

引用次数: 0

Inside Back Cover, Volume 2, Number 4, October 2023 内封底，第2卷，第4期，2023年10月

Droplet Pub Date : 2023-10-18 DOI: 10.1002/dro2.99

Mengyao Chen, Xiangying Shen, Lei Xu