LAB-ON-A-CHIP

BY YAROSLAV GERMANOV

MARCH 24, 2017

Outline

What is this technique about.

Short history

What is it made from

Applications

Case study 1

Conclusion

What is it?

A lab-on-a-chip (LOC) is a device that integrates one or several laboratory functions on a single chip.

History The history of lab-on-a-chip is intrinsically linked to

microfluidics.

Closely related to creation of photolithography and semiconductors development.

First real lab-on-a-chip was created in 1979 at Stanford University for gas chromatography. However, major lab-on-a-chip research only began in the late 80s with the development of microfluidics and the adaptation of micro fabrication processes for the production of polymer chips.

First made By Angell, A silicon wafer GC chip with column length 1.5 m, valve and detector

A few applications have been developed on micro GC systems, but research is still morededicated to reliable miniaturized system development rather than method development

What is it used for?

Biomedicine

Synthesis of small amounts of desired compound

Proteomics

Diagnostic devices for use at sites without access to full laboratory facilities.

Cell biology

Military

A second, different motivation for the development of microfluidic systems came with the realization-after the end of cold war- that chemical and biological weapons posed major military and terrorist threats. US department of Defense supported a series of programmes in 1990s aimed at developing field-deployable microfluidic systems designed to serve as detectors for chemical and biological threats. These programmes were the main stimulus for the rapid growth of academic microfluidic technology.

What is it made from?Thermoformed plasticheating a thermoplastic to make it soft so it can be put in a particular form.(very similar to polymer casting)

Glass designed for particular needsTransparent, compatible with micrometer sized machining, chemically inert.Largely been displaced nowadays*

Polymer casting(PDMS polydimethylsiloxane is used) optically transparent, soft elastomer, some very useful features as supporting a pneumatic valve

Paper based lab-on-a-chipLow cost technique, potentially may have strong outcomes for applications requiring ultra low-costs.(accessible to lower-income and limited-resource populations)

Silicon, SteelExpensive, hard to fabricate, opaque to UV light.Not common these days.*

*used in specific cases where stability to chemicals and temperature is required+ nanoscale microfluidics

Lab-on-a-chip architecture overview and key components

Injector

Transporter

Preparator

Mixer

Reactor

Separator

Detector

Controller

Power Supply

InjectorInjectors ensure precise micro/nanoliter volume delivery of sample or reagent into a lab on-a-chip for analytical process.Syringepumps and robotic pipettesare the most common injectors used

TransporterFluidic transporters control fluids flow sequence, flowduration, flow direction, and flow rate for fluid manipulation in LOC

PreparatorPreparators treat and isolate analyte of interest from crude biological sample for downstream analysis.

MixerMixer mixes multiple streams of fluids in microchannels of a lab-on-a-chip. Due to the low Reynolds numbers in a lab-on-a-chip, mixing of multiple liquids in mixers is performed based on laminar diffusion under normal conditions.

ReactorReactor maintains and controls a chemical or biological reaction in a controlled environment. The reactor is usually equipped with heaters, sensors, or actuators to control and monitor the reaction process.

SeparatorSeparators isolate sample and reagents after mixing orreaction processes. The separator module can be used toperform selection of a pre-determined cell for analysis, orisolation of a large number of single cells where usercannot identify and manipulate a pre-determined cell

DetectorDetectors identify and quantify analyte via predominantly optical methods due to the integration simplicity. Detectors consist of transducers that acquire physical signals from analyte and transform them into electrical signals for analysis.

Types of detectors. OpticalElectro chemicalMass spectroscopy detection Capacitive detection

ControllerControllers manage all on-chip control, data acquisition, and signal processing operations. They are responsible for issuing control signals to on-chip components such as actuators, heaters, and so on. They also gather data from on-chip sensors

Power SupplyPower supplies energize on-chip components includingtransducers, actuators, and electronic circuits. Portable lab-on-a-chip devices usually utilize batteriesas their power source.

Photograph of microfluidic biosensor(syringe pump,

optical detection, off-chip controller and off chip

power supply)

Statistical representation of disability adjusted life years main contributor infections.

Statistical data revealing the number of people leaving with HIV around the world with emphasis to developing countries.

An example of poorly equipped laboratory in Rwanda.

HIV detection by lab on a chip

An example of possible mChipwith a reader device designed to detect HIV antibodies in human whole blood.

HIV detection by LOC continued

Laboratory tested Tested in Rwanda

Video showing the time lapse for the analysis of the 2 samples.

Video showing that whole blood can be analyzed without clogging the micro channels.

Advantages of using the LOC for human health which ensure mass production of micro devices

Main advantages.

Low cost: Micro technologies will decrease the cost of analysis much in the way they decreased the cost of computed calculation. Integration will enable numerous tests to be performed on the same chip, reducing to a negligible price the cost of each individual analysis.

Potential increasing number of applications including “multi application platforms

Development of assays for home testing

Healthcare delivery and monitoring in developing economies.

Decrease of potential hazard by chemical contamination due to extremely low volumes of analytes used.

Limitations of lab-on-a-chip compared to classic technologies

Industrialization: Most lab-on-a-chip technologies are not yet ready for industrialization.

Lab-on-a-chip needs an external system to work: Even if lab-on-a-chip devices can be small and powerful, some of require specific machinery such as electronics or flow control systems to be able to work properly. Without a precise system to inject, split and control the positioning of samples, labs-on-a-chip usage is limited.

Absence of standardization which leads to occurrence of numerous chips with it’s own design and architecture.

Conclusion

The field of microfluidics is in early adolescence and lacks of essential requirements. As a field, it is a combination of unlimited promise and incomplete commitment. This is a very exciting time for the field , but we still don’t know exactly what it will be when it grows up.