HALDIA INSTITUTE OF TECHNOLOGY

Presentation on Lab on a Chip technology

Submitted by SANJIB PASHI (Department OF AEIE)

Contents• Introduction• What is LOC• Chip materials & fabrication technology• Electronic circuitry on lab-on-chips• Role of Nanotechnology• Advantages • Disadvantages• Application• Conclusion

Introduction• Lab-on-a-chip refers to technologies which allow operations which normally require a laboratory synthesis and analysis of chemicals on a very miniaturized scale, within a portable or handheld device. • A typical lab-on-chip device contains micro channels, which allow liquid samples to flow inside the chip, but also integrates measuring, sensing and actuating components.

What is LOC ?• A lab-on-a-chip (LOC) is a device that integrates one or several laboratory functions on a single chip of only millimeters to a few square centimeters in size.• Lab-on-chip technology focuses on the development of hybrid devices, which integrate fluidic and electronic components onto the same chip.• Basically lab-on-chip integrate nonmaterial, micro fluidics, nanosensors, micro electrics, biochemistry, fluidic and electronic components onto the same chip.

Chip materials & fabrication technology Chip materials

•lab-on-chip devices are hybrids that combine glass, silicon and various polymers like acrylic, polyester, polycarbonate, resists, thermoplastics or molds like the polydimethylsiloxane (PDMS).

• Silicon, glass or polymers are suitable for making the microfluidic components of the chips; metals like gold, platinum or titanium are used for the conductive parts; silicon dioxide, silicon nitride and titanium nitride are for insulation and passivation.

FABRICATION PROCESSLab-on-chip fabrication techniques are analogous to those of microelectronics, since closely related micro fabrication and integration methodologies are shared by both.

There are 3 way of fabrication process:-

Deposition method

Etching process

Bonding

Deposition method•Here we can use any vapour deposition process that produces thin metal, ceramic, or compound films, through thermal oxidation in a gas chamber at an elevated temperature.

(a) Metallization of the substrate by sputtering a metal film of Au, Pt, or ITO.

(b) Spin coating of photosensitive resist film onto the metal film.

Etching process

In lab-on-chip fabrication technology, patterning is the transfer of outlines of features (which define micro channels, microelectrodes, or other components) on the top of a substrate by means of ultraviolet illumination via a photo mask.

(c) exposure of the photosensitive film via a photo mask that results in the transfer of the desired electrode patterns onto the photosensitive film.(d) after photo-development, chemical etching removes the bare metalized areas, which results in the formation of the electrodes.

Bonding After patterning all features on substrates (micro channels, elements, inlets, etc), the base plate and the cover plate must be bonded in order to seal the chip. It is possible to bond silicon, glass, or rigid polymer plates, by bonding

Bond the PDMS channel to a glass substrate

Electronic circuitry on lab-on-chips

• The sensor is followed by an analogue front-end, which conditions the measuring signal, analogue-to digital converters (ADC), and a digital signal processor that analyses the signal.

analogue front-end

• The signals can be electrical, optical, etc.

The analyzed data further sent via a bus to external computer for post-processing, or even visualized on integrated displays or external screen.

Role of Nanotechnology• Nanosensors are also a key element of many lab-on-a-chip systems. Sensors have been developed using nano materials like carbon nano tubes, capable of detecting very low concentrations, even down to single molecules in some cases. These are extremely useful in allowing a high degree of analytical flexibility in a lab-on-a-chip system without increasing the overall size of the device.

Advantages• Faster analysis and response times due to short diffusion distances, fast heating, high surface to volume ratios, small heat capacities.• Better process control because of a faster response of the system (e.g. thermal control for exothermic chemical reactions)• Compactness of the systems due to integration of much functionality and small volumes• Massive parallelization due to compactness, which allows high-throughput analysis• Lower fabrication costs, allowing cost-effective disposable chips, fabricated in mass production

Disadvantages• Novel technology and therefore not yet fully developed.• LOCs more complex than in conventional lab equipment.• Detection principles may not always scale down in a positive way, leading to low signal-to-noise ratios.

APPLICATION•Personalised medicine

•Point-of-care diagnostics

•Marine sensors

•Monitor pollution

•Monitor pandemics / diseases

•Link to medical and patient databases

•Usage as terminal testers

•Military medicine

Conclusions•Future advancements in lab-on-a-chip technology will always depend on at least two major scientific disciplines - microfluidics, and molecular biology. Nanotechnology will play a key role in tying these two fields together as the technology progresses.•Despite the hurdles always associated with commercialization of a new technology, viable examples of these devices are beginning to appear on the market. It seems that lab-on-a-chip technology will become increasingly important in the coming years, both in the medical world and in the chemical industry

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