DESIGN AND APPLICATION OF DIGITAL MICRO FLUIDIC BIOCHIP Presented by : BENGAL INSTITUTE OF TECHNOLOGY
• What is biochip?• Types of Biochip• Introduction• Motivation for Biochip• Digital Microfluidic Biochip• Actuation Principle• Advantages• Application• Conclusion
Biosensor or bioprocessor that utilizestechnologies of modern Biology andElectronics in a micro scale.
DNA chip Protein chip Enzyme chip Lab-on-a-chip
Lab-on-chip: Systems for performing biomedical analyses of very small quantities of liquids Advantages: Fast reaction times Low-cost, portable and disposable Compactness massive parallelization high-throughput Types: Continuous-flow: enclosed, interconnecting, micron-dimension channels Digital: discrete droplets of fluid across the surface of an array of electrodes.
Transfer conventional biochemical laboratory methods to lab-on-a-chip (LoC), or microfluidic biochips Potential to revolutionize biosensing, clinical diagnostics, drug discovery -Small size and sample volumes -Lower cost -Higher sensitivity
Based on precise control of very small volumes of liquids Integrate various fluid-handling functions such as sample preparation, analysis, separation, and detection Most commercially available microfluidic devices are continuous-flow -Permanently etched microchannels, pumps, and valves (Duke University) 2002
Digital microfluidic biochips (DMBs) -Manipulate discrete droplets (smaller volumes) -Electrical actuation -No need for cumbersome micropumps and microvalves -Dynamic reconfigurability (virtual routes) -Architectural scalability and greater automation Fig. 2. (a) Basic cell used in an EWOD-based digital micro fluidic biochip; (b) a two-dimensional array for digital micro fluidics [Pollack 2001].
Droplets containing samples travel inside filler medium (e.g., silicone oil), sandwiched in between glass plates Bottom plate – patterned array of control electrodes Top plate – continuous ground electrode Surfaces are insulated (Parylene) and hydrophobic (Teflon AF) Droplet transport occurs by removing potential on current electrode, applying potential on an adjacent electrode Interfacial tension gradient created
Fig. 4. Side-view of digital micro fluidic platform with a conductiveglass top plate (left). Materials and construction of the actuator(right). By adding a conductive top plate and adding individuallyaddressed buried electrodes in the bottom plate, the droplet can beactuated from one electrode position to the next by the application ofvoltage.
It has no moving parts. It requires no channels. It controls many droplets independently because the electro wetting force is localized at the surface. It works with a wide variety of liquids ----- that is, most electrolytic solution. It is compatible with microscopy. Glass substrate and transparent indium-tin-oxide (ITO) electrodes makes the chip compatible with observation from a microscope. It is extremely energy efficient ---- using nanowatts to microwatts of power per transfer.
In most diagnostic and chemical detection applications, a key challenge is the preparation of the analyzed for the presentation to the on-chip detection system. In tissue-engineering application, the challenge is to high-resolution (less than 10 micron) 3D tissue constructs with embedded cells and growth factors by manipulating and maintaining live cells on the chip platform. A new application can be introduced, including detection of airborne sulfates obtained by air sampling, DNA pyro sequencing, and a biomimetic manufacturing process for soft-tissue engineering. On-chip assays for determining the concentration of target analysts is a natural application for digital micro fluidics.
o This technique is faster for analyzing various components present in blood, urine, split as well as air born sample.o Small amount of sample is enough to test various parameters.o Small size instrument is also advantages upon conventional analyzer, which can easily carry and also goes in spacecraft for diagnosis.o Cost effectiveness is also an important advantage over the conventional instrument.o In a very short time various parameters can be tested simultaneously from a sample.