Elbuken Research Group

Lab-on-a-chip Systems

lab-on-a-chip
The advancements in biochemical sciences had revolutionizing impact on all aspects of our social life. The insight that we have at micro and nanoscale opened a new research domain that requires fully equipped laboratories. Although there have been several analysis tools and techniques developed, there is still growing need for development of novel devices. Lab-on-a-chip devices are intended to fill this gap especially for scenarios that require handling of minute amounts of liquids.

Lab-on-a-chip systems have their roots in microfluidics which is a discipline that deals with physics of fluids at micrometer scale. With the reduction of size to micron scale, fluids start exhibiting non-intuitive behaviours. By exploiting these properties, it is possible to perform complicated biological and chemical operations on miniaturized devices. These lab-on-a-chip devices require very little amount of sample and can also be designed to combine several operations in a single device.

Our efforts are focused on development of “sample-in, result-out” type of lab-on-a-chip systems. Although there are several interesting examples of lab-on-a-chip systems, there is still need for well integrated, robust and all-in-one systems. We are interested in developing true lab-on-a-chip systems that can operate with minimal user intervention. We are developing these systems for biomanipulation and biocharacterization applications.

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Microdroplets

Imagine pipetting femtoliters of liquids in a precise manner! Imagine performing this pipetting at the rate of 1000 operations in a second. You would probably be called a Super Researcher from Krypton!!! Well, don’t get to pessimistic, microdroplet based fluidic systems allows you just to do that.

Instead of using a single liquid, two immiscible liquids in a microchannel leads to formation of microdroplets. Using specific designs, it is possible to form these droplets with different shapes, speeds and contents. The rate of the droplet formation can be adjusted according to the given application. These microdroplets can be though of as individual beakers for your experiment. Due to inherent inherently formed vortices, it is very easy to mix different fluids in microdroplets. One can use these droplets to capture individual cells or finite amounts of biological material for statistical studies.

We have been working on several aspects of microdroplet formation. We have expertise in microdroplet formation using different microchannel designs as well as detection of microdroplets using low-cost, very small footprint sensors. We have also studies on monitoring of biological activities in microdroplets. The sensors that have been developed by our group can be used for not only counting microdroplets but also to meausure their dielectric content. Please see our publications for more details.

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Point-of-care Systems

 One of the biggest applications of microfluidic systems is in the field of point-of-care systems. Arguably the most influential microfluidic products in the market are handheld glucosemeters and strip tests (e.g. pregnancy strip test). These products have been utilizing microfluidic principle way before the term “micro-total-analysis system” was coined in 1990.

Currently, it is the microfluidic scientist’s ultimate goal to have their techniques prototyped into point-of-care products. These systems work with minute amounts of liquid and can deliver diagnostic results at the comfort of your home or next to the patient at even physician’s office. Therefore, the long and costly sample analysis cycle is cut down to a simple fingerprick sampling.

We are also working on development of point-of-care microfluidic systems for rapid and diagnosis from bodily fluids. We have been developing systems for low cost plasma separation and detection of blood proteins, as well as disorders related with inflammation and coagulopathy.  The development of such systems requires combination of new scientific methods together with engineering approaches from mechanical and electrical engineering. Our group has expertise in development of handheld prototypes as well as disposable cartridges. The ideal point-of-care product works with single use cartridges, so that contamination between different runs is avoided. This requirement has opened a new research direction on rapid prototyping in our group.

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Rapid Prototyping

 In today’s technology driven world, it is an important requirement to turn ideas into reality. Although it has not been the core research direction for most laboratories, development of rapid prototyping techniques enables scientists on improve their ideas by testing them rapidly. We learn more from our failures than our achievements. Therefore, we value the ability to put our ideas into test very much. Towards this goal, we are actively working on rapid prototyping of microfluidic and lab-on-a-chip systems.

This research direction has emerged from our own necessities in our laboratory. We enjoy very much on working our quick and dirty methods and to turn them into internationally accepted methods. Currently, we are working on two novel methods that we believe will have a significant potential in the field of microfluidics. We are working on fabrication of conventional PDMS molds in less than 2 hours without any clean room process. Our initial results have shown that we can fabricate very well controlled microchannels with straight channel walls using standard laboratory tools. Another interesting project, we are working on is the development of 3D microelectrodes integrated with microchannels. Both of these techniques are currently being perfected with our group and will be shared with the scientific community shortly.