Lab on a Chip Blog

Written for Chemistry World 

Scientists in the US have discovered that Lego bricks can be an effective way of constructing modular microfluidic systems.

A remotely controlled micro-robot uses air bubbles to grip on to and assemble sub-millimetre sized components.

The microgripper lifts a poly(ethylene glycol) diacrylate hydrogel disc (pink) and stacks it on top of a another hydrogel disc (blue).

Source: Royal Society of Chemistry

Gripping and manipulating sub-millimetre objects is a tricky problem in microrobotics. Mechanical grasping is difficult at micro level, and techniques such as micro-machined grippers, although very accurate, need to be tethered to a control system and so are unsuitable for work in confined spaces.

To overcome these problems, Metin Sitti and his team from the Max Planck Institute in Germany have developed an untethered microgripper, which uses surface tension, rather than mechanical means, to grab small parts, such as a hair, a cloth fibre or a piece of muscle tissue. The gripper works in an aqueous environment, can grab both hydrophilic and hydrophobic items and, unlike other systems, does not need to be customised to fit to the item.

Read the full article in Chemistry World.

Introducing graphene into microfluidic devices can make it easier to study proteins at an atomic level, scientists in the US have shown. Devices that are thinner and interfere less with the measurements allow larger and more intricate protein structures to be resolved using techniques that rely on probing thousands of microcrystals.

Not only does this reduce the device’s thickness, improving the signal-to-noise ratio, the graphene also acts as a barrier to prevent the sample evaporating. John Helliwell, an expert in crystallography at the University of Manchester in the UK, explains that preventing water loss from the crystal is ‘vital…because the sample hydration state needs to be preserved for its molecular integrity’.

Perry’s group are now focusing on shrinking down the dimensions and increasing the complexity of the device, as well as studying the structure of proteins involved in programmed cell death.

To read the full article visit Chemistry World.

Click the link below to read the original research paper published in Lab on a Chip for free*:

*Article is free to access until 26/07/2016 through a RSC registered account – click here to register

In the US, over 30 million people wear contact lenses and each year around 60,000 contract serious eye infections that put them at risk of going blind. Thorough cleaning is vital to prevent bacterial build-up on the lens but research has also shown that an individual’s tear chemistry affects the effectiveness of cleaning solutions.

Personalised care products can prevent serious eye infections caused by ineffective contact lens cleaning solutions

The team use their device to demonstrate how tears impacts lens selection and care, and say it could be adapted for point-of-care testing in eye clinics.

Please visit Chemistry World to read the full article.

Contact lens-on-a-chip companion diagnostic for personalized medicine
Allan Guan, Yi Wang, Kenneth Scott Phillips and Zhenyu Li
Lab Chip, 2016, Accepted Manuscript
DOI: 10.1039/C6LC00034G

*Access is free through a registered RSC account until 8th April 2016 – click here to register

Scientists in Switzerland have incorporated pulsing human heart tissue into a microfluidic device to make a miniscule model of a living system that could be used to test new drugs.

The hanging drops are connected through 200μm-wide channels

‘This is one of the most interesting recent developments in the field of microfluidic systems,’ comments Wouter van der Wijngaart, who heads up the research into micro- and nanofluidic systems at the KTH Royal Institute of Technology in Sweden. ‘This type of system has the potential to become the de facto workhorse in the field of 3D microtissue culturing.’

Please visit Chemistry World to read the full article.

Adding the ‘heart’ to hanging drop networks for microphysiological multi-tissue experiments*
Saeed Rismani Yazdi, Amir Shadmani, Sebastian C. Bürgel, Patrick M. Misun, Andreas Hierlemann and Olivier Frey
Lab Chip, 2015, Advance Article
DOI: 10.1039/C5LC01000D

*Access is free through a registered RSC account until 19 November 2015 – click here to register

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

We’ve had microfluidics. We’ve even had nanofluidics. But now, scientists have gone a step smaller by pushing femtofluidics into the realms of possibility.

Droplet microfluidics enables assays and reactions to be performed in droplets of reagent that are just a few nanolitres or picolitres in volume. The main advantages of this are that reactions can be performed in a massively parallel manner using hardly any reagent, and further miniaturisation to give femtolitre droplets promises to enable even higher-throughput with even lower reagent use.

Please visit ChemistryWorld to read the full article .

Droplet-based microfluidics at the femtolitre scale*
Marie Leman, Faris Abouakil, Andrew D. Griffiths and Patrick Tabeling
Lab Chip, 2015, Advance Article
DOI: 10.1039/C4LC01122H

*Access is free through a registered RSC account until 13 November 2014 – click here to register