Lab on a Chip Blog

The front cover of Issue 23 shows work from Meng Sun et al. who have produced a static droplet array with the capability for tunable concentration gradients.   Their technique involves the controlled exchange of materials between moving plugs and stationary drops, and the concentration of soluble reagents can be varied from drop to drop  at well-defined time points.

Microfluidic static droplet arrays with tuneable gradients in material composition
Meng Sun, Swastika S. Bithi and Siva A. Vanapalli
DOI: 10.1039/C1LC20709A

On the inside front cover we have an image from Kwang Oh and coworkers describing their method for droplet combination in microfluidic devices that allows passive parallel synchronisation.  They describe the layout as being analogous to a train track, as the network consists of a top channel, a bottom channel, and ladder-like connections between the two main channels.

Parallel synchronization of two trains of droplets using a railroad-like channel network
Byungwook Ahn, Kangsun Lee, Hun Lee, Rajagopal Panchapakesan and Kwang W. Oh
DOI: 10.1039/C1LC20690G

The back cover highlights work from Nan-Nan Deng et al on the economical production of microfluidic devices for monodisperse droplet formation.  The simple device fabrication, using inexpensive tools and supplies, is flexible, offering easy spatial patterning of surface wettability, and good chemical compatibility and optical properties.

Simple and cheap microfluidic devices for the preparation of monodisperse emulsions
Nan-Nan Deng, Zhi-Jun Meng, Rui Xie, Xiao-Jie Ju, Chuan-Lin Mou, Wei Wang and Liang-Ying Chu
DOI: 10.1039/C1LC20629J

View the rest of the issue online here, which including all our latest hot articles on a micro-hydrocyclone for particle separation, sustainable microinjection moulding, broadband for droplets, clinical-scale bubble production and streaming potential for energy

On the back cover of Issue 22 we’re featuring research from the Micro and Nano-Scale Transport Laboratory, Department of Mechanical Engineering, University of Alberta.

The Reservoir-on-a-Chip, or ROC for short, by Sushanta K. Mitra et al. is a novel miniaturization approach to study oil recovery in a microfluidic device, mimicking the pore structure of a naturally occurring oil-bearing reservoir rock in an etched silicon substrate.  The device will enable researchers to better understand pore-scale transport relevant to reservoir engineering.

Download the article for the details:

Reservoir-on-a-Chip (ROC): A new paradigm in reservoir engineering
Naga Siva Kumar Gunda, Bijoyendra Bera, Nikolaos K. Karadimitriou, Sushanta K. Mitra and S. Majid Hassanizadeh
Lab Chip, 2011, 11, 3785-3792
DOI: 10.1039/C1LC20556K

On the outside front cover of Issue 22 we have an image from Aleksei Aksimentiev (University of Illinois) et al. highlighting their work modelling the transport of solutes through nanochannels with sticky surfaces.  Their method allows Brownian dynamics simulations of nanofluidic systems with retention of atomic-scale precision in the description of solute interactions, without incurring the huge cost of molecular dynamics simulations.

Atoms-to-microns model for small solute transport through sticky nanochannels
Rogan Carr, Jeffrey Comer, Mark D. Ginsberg and Aleksei Aksimentiev

On the inside front cover a paper from Carolyn Ren and colleagues at the University of Waterloo is displayed.  They have sought to understand the chaos that can be created at junctions in microfluidic channels and have developed a model to describe droplet sorting in different geometries, droplet resistances and pressures.

Passive droplet trafficking at microfluidic junctions under geometric and flow asymmetries
Tomasz Glawdel, Caglar Elbuken and Carolyn Ren

View the rest of the issue online here

On the front cover of Issue 21 Hatice Altug et al. demonstrate the first example of a large-scale plasmonic microarray with over one million sensors on single microscope slide.

Large-scale plasmonic microarrays for label-free high-throughput screening
Tsung-Yao Chang, Min Huang, Ahmet Ali Yanik, Hsin-Yu Tsai, Peng Shi, Serap Aksu, Mehmet Fatih Yanik and Hatice Altug
Lab Chip, 2011, 11, 3596-3602
DOI: 10.1039/C1LC20475K

The inside front cover highlights the review from Jurgen Popp on droplet-based microfluidic systems in Raman and SERS.

Droplet formation via flow-through microdevices in Raman and surface enhanced Raman spectroscopy—concepts and applications
Anne März, Thomas Henkel, Dana Cialla, Michael Schmitt and Jürgen Popp
Lab Chip, 2011, 11, 3584-3592
DOI: 10.1039/C1LC20638A

And on the back cover is work from Piotr Garstecki et al.  showing their results on the speed of individual droplets in microfluidic channels – revealing quite a complex landscape of functional dependencies.

Speed of flow of individual droplets in microfluidic channels as a function of the capillary number, volume of droplets and contrast of viscosities
Slawomir Jakiela, Sylwia Makulska, Piotr M. Korczyk and Piotr Garstecki
Lab Chip, 2011, 11, 3603-3608
DOI: 10.1039/C1LC20534J

As with all our cover article, these are free to access for the next 6 weeks.

On the cover of Issue 20 we have hot articles from Ye and Demirci et al., Liu and Kokini et al. and Ren and Wu et al.

The outside front cover depicts Bin Ye and Utkan Demirci‘s paper where they have demonstrated that a mobile phone can be used to image and process the results of an ELISA (enzyme-linked immunosorbent assay) test on a microchip, reducing previously bulky equipment to a size where it could be used at the bedside.

Integration of cell phone imaging with microchip ELISA to detect ovarian cancer HE4 biomarker in urine at the point-of-care
ShuQi. Wang, Xiaohu Zhao, Imran Khimji, Ragip Akbas, Weiliang Qiu, Dale Edwards, Daniel W. Cramer, Bin Ye and Utkan Demirci
Lab Chip, 2011, 11, 3411-3418

The inside front cover highlights green microfluidic research from Gang Logan Liu and Jozef L. Kokini, where they have used a by-product from corn – zein – instead of the traditional plastics to produce a microfluidic device.  This article was also highlighted in Chemistry World.

Green microfluidic devices made of corn proteins
Jarupat Luecha, Austin Hsiao, Serena Brodsky, Gang Logan Liu and Jozef L. Kokini
Lab Chip, 2011, 11, 3419-3425

And on the back cover is work from Hongwen Ren and Shin-Tson Wu where they report a novel approach which can extensively spread a liquid crystal interface, which opens a route to new voltage controllable, polarization-insensitive, and broadband liquid photonic devices.

Voltage-expandable liquid crystal surface
Hongwen Ren, Su Xu and Shin-Tson Wu
Lab Chip, 2011, 11, 3426-3430

On the front cover of Issue 19 is an article from Aaron Wheeler et al. on their new method for the analysis of dried blood spot samples. The method has the potential to offer automation of dried blood samples, which are useful for a number of clinical and pharmaceutical applications due to the small sample sizes involved and ease of storage.  The team have developed a prototype microfluidic system to quantify amino acids in which analytes are extracted, mixed with internal standards, derivatized, and reconstituted for analysis by tandem mass spectrometry.

This hot article was also recently reported on in C&EN.

A digital microfluidic method for dried blood spot analysis
Mais J. Jebrail, Hao Yang, Jared M. Mudrik, Nelson M. Lafrenière, Christine McRoberts, Osama Y. Al-Dirbashi, Lawrence Fisher, Pranesh Chakraborty and Aaron R. Wheeler
Lab Chip, 2011, 11, 3218-3224
DOI: 10.1039/C1LC20524B

On the cover this month are two hot articles from Nicholas A. Melosh et al. and Malancha Gupta et al, and both articles are free to download for the next 6 weeks.

Nicholas Melosh’s article on the outside front cover depicts their method for controlled chemical delivery in microfluidic cell culture devices without fluid flow over the cells, thereby avoiding the problem of cell perturbation.

Rapid spatial and temporal controlled signal delivery over large cell culture areas
Jules J. VanDersarl, Alexander M. Xu and Nicholas A. Melosh
Lab Chip, 2011, 11, 3057-3063
DOI: 10.1039/C1LC20311H

On the inside front cover, the image from Malancha Gupta highlights a vapour deposition method to line the surfaces of PDMS microfluidic devices with a cross-linked fluoropolymer barrier coating, which significantly increases the chemical compatibility of the devices.

Vapor deposition of cross-linked fluoropolymer barrier coatings onto pre-assembled microfluidic devices
Carson T. Riche, Brandon C. Marin, Noah Malmstadt and Malancha Gupta
Lab Chip, 2011, 11, 3049-3052
DOI: 10.1039/C1LC20396G

For the rest of the issue, including hot articles see here