Archive for May, 2015

Free access to April’s HOT articles

These HOT articles published in April 2015 were recommended by our referees and are free* to access for 4 weeks


Active pneumatic control of centrifugal microfluidic flows for lab-on-a-chip applications
Liviu Clime, Daniel Brassard, Matthias Geissler and Teodor Veres
Lab Chip, 2015,15, 2400-2411
DOI: 10.1039/C4LC01490A

Graphical Abstract


Exosome isolation: A microfluidic road-map
A. Liga, A. D. B. Vliegenthart, W. Oosthuyzen, J. W. Dear and M. Kersaudy-Kerhoas
Lab Chip, 2015,15, 2388-2394
DOI: 10.1039/C5LC00240K

Graphical Abstract


Micromilling: A method for ultra-rapid prototyping of plastic microfluidic devices
David J. Guckenberger, Theodorus E. de Groot, Alwin M. D. Wan, David J. Beebe and Edmond W. K. Young
Lab Chip, 2015,15, 2364-2378
DOI: 10.1039/C5LC00234F

Graphical Abtrsct

Take a look at our Lab on a Chip 2015 HOT Articles Collection!

*Access is free until 29.06.15 through a publishing personal account. It’s quick, easy and free to register

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Direct measurement of the tensile strength of water using an optofluidic chip

As children, you may remember being fascinated by pond skaters and their ability to walk on water. This is due to water’s high surface tension and there are numerous other ways in which this property is vital to many biological functions. It is also an important factor to take into account when it comes to engineering, and therefore it is essential that there is an accurate and straight forward method for measuring surface tension.

To measure this property, the pressure has to be reduced to such an extent that it causes the water to rupture and form vapour cavities. These vapour cavities must be a result of homogeneous nucleation alone and not heterogeneous nucleation (so should occur spontaneously and randomly, rather than due to nucleation sites). The pressure at which cavitation occurs in termed the tensile strength.

Previous methods have shown a large discrepancy in results, due to the requirement of large volumes of water leading to heterogeneous nucleation. More recently, the mineral inclusion method has overcome this, however has other limitations, such as the requirement of an autoclave. Alternatively, microfluidics allows the use small volumes of water to ensure homogenous nucleation, but this method is limited to low-viscosity liquids.

Graphical Abstract

Dr. Liu Ai Lin and co-workers, at NTU, Singapore, have reported the direct measurement of water’s tensile strength using an optofluidic chip. Their method relies on an infrared laser that is focussed into a microchannel partially filled with water. The laser pulse results in the formation and recombination of plasma, which in turn produces a bubble, causing a spherical shock wave. The reflection of the shock wave on the air-water interface generates a negative pressure and, if this is larger than the tensile strength, the water ruptures, causing nucleation of vapour bubbles near the interface. The pressure value can be attained by both measuring the spreading of the shock wave over time and the displacement of the water-air interface.

By imaging the microchannel at increasing standoff distances (defined in the diagram above), the distance and pressure at which water no longer ruptures can be found. This can be directly converted to a value for the tensile strength.

Graphical Abstract

This work provides a simple, low-cost method for calculating tensile strength that can easily allow rapid testing of a wide range of samples. In order to demonstrate this, the authors also measured the tensile strength of glycerol, a highly viscous fluid.

To download the full article for free* click the link below:

Water’s tensile strength measured using an optofluidic chip
Z. G. Li,  S. Xiong,  L. K. Chin,  K. Ando,  J. B. Zhang and  A. Q. Liu
DOI: 10.1039/ C5LC00048C

*Access is free through a registered RSC personal publishing account

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Gecko-inspired adhesives for microfluidics

Scientists from Canada report an affordable manufacturing advance in microfluidics with a dry adhesive system that demonstrates strong, self-healing and reversible bonding.

This new adhesive technology will make complex microfluidic patterns much simpler to assemble,’ says Ali Dhinojwala, from the University of Akron, US, who is also interested in mimicking the sticking power of geckos. ‘By incorporating mushroom-shape tips in the fabrication of the device, they demonstrate reversible seals with larger burst pressures than PDMS-based devices.’

Please visit Chemistry World to read the full article.


Gecko gaskets for self-sealing and high-strength reversible bonding of microfluidics
A. Wasay and D. Sameoto
Lab Chip
, 2015, Advance Article
DOI: 10.1039/C5LC00342C

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New You Tube Videos

Centrifugal step emulsification applied for absolute quantification of nucleic acids by digital droplet RPA 


 
 
  
Highly efficient microfluidic sorting device for synchronizing developmental stages of C. elegans based on deflecting electrotaxis 
 


 
  
A high-throughput microfluidic single-cell screening platform capable of selective cell extraction 

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New YouTube videos

Optofluidic holographic microscopy with custom Field of View by a linear array detector


Active pneumatic control of centrifugal microfluidic flows for lab-on-a-chip applications

Moving droplets between closed and open microfluidic systems

Optofluidic Guiding, Valving, Switching and Mixing based on Plasmonic Heating in Random Gold Nanoisland Substrate

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Pioneers of Miniaturisation Lecture 2015

Lab on a Chip will again join forces with Corning Incorporated to award the ninth ‘Pioneers of Miniaturisation’ Lectureship at µTAS, including a certificate of recognition and a prize of $5000.

Miniaturisation plays a significant role in our daily lives; devices are becoming smaller and smaller, and this trend is set to continue. Current micro and nano fluidic research encompasses many scientific developments and technologies that will increase our understanding of phenomena at the micro and nano scale and potentially have a huge positive impact on our lives in the future. The use of micro and nano fluidic technologies will impact on a diverse range of industries ranging from their use in motor cars, through health improvement applications and to their use in protecting national and environmental security needs.

Nomination Deadline: 10th July 2015

At Lab on a Chip, we strongly believe in this technology and have been willing to show the necessary commitment and financial support to back the development of this research community. It is in this vein we present this award to honour and support the up and coming, next generation pioneers in this field of endeavour. This years lectureship will be presented at the µTAS 2015 Conference in Gyeongju, Korea.

Who should you nominate?

  • Early to mid-career scientists.
  • Scientists who have demonstrated extraordinary or outstanding contributions to the understanding or development of miniaturised systems. This will be judged mainly through their top 1-3 papers and/or an invention documented by patents/or a commercial product. Awards and honorary memberships may also be considered. The awardee is required to give a short lecture at the µTAS Conference in the same year.

Who has won the Pioneers of Miniaturisation Lectureship in the past?

  • The 2014 Pioneers of Miniaturisation Lectureship was awarded to Sangeeta Bhatia, MIT.
  • Further information  on past winners can be found on our webpage.

How do I nominate?

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