An impressive approach for incorporating parallelism in designing DMFB with cross contamination avoidance
26 Jun 2015-pp 1-6
TL;DR: This paper effectively does the task in parallel for five such sets of sub regions of a given restricted sized chip in Digital microfluidics using an array based partitioning pin assignment technique, where cross contamination problem has been considered, and efficiency of proper taxonomy of agiven sample has also been improved.
Abstract: These days, in emergency, multiple assay operations are required to be performed at parallel Area of a given chip as a constraint, how efficiently we can use the chip and how much parallelism can be built-in are the objectives of this paper A typical application of an assay may characterize a sample where, say only one type of reagent and multiple samples have been considered, or vice versa, and identify some factor(s) of the sample(s) under requirement in parallel A generalized application may also consider more samples and more reagents for respective findings at parallel In our experimentation, we effectively do this task in parallel for five such sets of sub regions of a given restricted sized chip in Digital microfluidics using an array based partitioning pin assignment technique, where cross contamination problem has also been considered, and efficiency of proper taxonomy of a given sample has also been improved
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TL;DR: This work essentially does this task in parallel for five such sets of subregions of a given restricted sized chip in digital microfluidics using an array based partitioning pin assignment technique, where cross contamination problem has been considered, and efficiency of proper taxonomy of agiven sample has also been improved.
Abstract: Digital microfluidic biochips are reforming many areas of biochemistry, biomedical sciences, as well as microelectronics. It is renowned as lab-on-a-chip for its appreciation as a substitute for laboratory experiments. Nowadays, for emergency purposes and to ensure cost efficacy, multiple assay operations are essential to be carried out simultaneously. In this context, parallelism is of utmost importance in designing biochip while the size of a chip is a constraint. Hence, the objective of this study is to enhance the performance of a chip in terms of its throughput, electrode utilisation, and pin count as well. Here, the authors have considered some of the most familiar assay requirements where a sample is to be analysed using different reagents, and identify some parameter(s) of the sample(s) under consideration. Moreover, sample preparation is a vital task in digital microfluidic biochip; thus, dilution of different samples up to different concentrations using buffer (neutral) fluid is a crucial issue. In this design, the authors effectively perform this task in parallel in a number of sub-regions of a given restricted sized chip using an array based partitioning pin-assignment technique while taking care of the cross contamination problem. The design has been verified for some significant real life assay examples.
3 citations
01 Mar 2017
TL;DR: This project work attempts to propose a simultaneous wash out routing algorithm for dynamic parallel droplet testing with reduced timing overhead and attends to utilize both the modified version of the solution.
Abstract: Digital microfluidic biochip (DMFB) is a technology that has just came up with the aim to attenuate droplets activity on a chip. By manipulating droplets with negligible volumes, the DMFB provides susceptibility with comparatively less human errors than the former routing methods. When two droplets are sharing a same routing path, the second droplet may be contaminated due to the leftovers of the first droplet which affects the assay. To avoid cross contamination 1. A DMFB need to be periodically washed out. 2. Contamination aware routing path need to be calculated. This work attends to utilize both the modified version of the solution. This project work attempts to propose a simultaneous wash out routing algorithm for dynamic parallel droplet testing with reduced timing overhead. A reconfigurable DMFB (Digital Microfluidic Biochip) test bed architecture with N × N pin structure will be designed using HDL. Parallel droplets will be introduced using different input pin channels with addition to that a wash out droplet will also be introduced and kept idle initially. When the destination pins for the actual droplets is configured, shortest path routing prediction will take place in parallel with a multi-objective modified swarm intelligence algorithm which is initiated to predict the routing path of the wash droplet to avoid cross contamination possibilities for the testing droplets. The second routing algorithm is dedicated for wash droplet through which is analyzes the first (droplet) routing result to find possible cross contamination. The modified swarm routing will be gated in case of non-contaminated routing path is already predicted in the first routing which saves the circuit power dissipation.
1 citations
Cites background from "An impressive approach for incorpor..."
...[8] Debasis Dhal, Piyali Dutta, Arpan Chakrabarty, Sudipta Roy and Rajat Kumar Pal “An Impressive Approach for Incorporating Parallelism in Designing DMFB with Cross Contamination Avoidance”....
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...In parallel assay operation, the assay washing duration is reduced before starting another assay and cross contamination is eventually avoided [8]....
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23 Jul 2020
TL;DR: A proactive wash droplet routing that take wash capacity into account is proposed that shows improvement in washing time and total turn around time and a newwash droplet is moved in to replace the exhausted wash droplets.
Abstract: Contamination occurs when multiple droplets share few cells in their route. When the first droplet passes through a shared cell, it lefts a strain of residue on this cell. At later time cycle, when the second droplet traverses through this shared cell, the leftover residue contaminates it. This may leads to erroneous experimental outcome. To avoid this, wash droplets are used for cleaning the residue. The wash droplets are sandwiched in between two functional droplets. In this article, we propose a proactive wash droplet routing that take wash capacity into account. Here, every functional droplet is tailgated by a wash droplet. When wash droplet capacity is exhausted, a new wash droplet is moved in to replace the exhausted wash droplet. Experimental result shows improvement in washing time and total turn around time.
1 citations
Cites background from "An impressive approach for incorpor..."
...The residue left on a shared cell by the a functional droplet is called contamination spot [3], [8], [14]....
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TL;DR: In this paper , a cross-referencing digital microfluidic biochips (DMFBs) with an efficient module placement design can be declared as a multifunctional chip or not, and a chip design which incorporates parallelism for enhancing performance in terms of assay completion time while performing multiple types of bioassays.
1 citations
References
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01 Jan 1979
42,654 citations
01 Jan 1978
TL;DR: This is the second edition of a quarterly column the purpose of which is to provide a continuing update to the list of problems (NP-complete and harder) presented by M. R. Garey and myself in the authors' book ‘‘Computers and Intractability: A Guide to the Theory of NP-Completeness’’.
1,943 citations
"An impressive approach for incorpor..." refers background in this paper
...By the way, this problem is analogous to clique partitioning problem in graph theory, which is known to be NP-hard [10]....
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TL;DR: To understand the opportunities and limitations of EWD microfluidics, this paper looks at the development of lab-on-chip applications in a hierarchical approach.
Abstract: The suitability of electrowetting-on-dielectric (EWD) microfluidics for true lab-on-a-chip applications is discussed. The wide diversity in biomedical applications can be parsed into manageable components and assembled into architecture that requires the advantages of being programmable, reconfigurable, and reusable. This capability opens the possibility of handling all of the protocols that a given laboratory application or a class of applications would require. And, it provides a path toward realizing the true lab-on-a-chip. However, this capability can only be realized with a complete set of elemental fluidic components that support all of the required fluidic operations. Architectural choices are described along with the realization of various biomedical fluidic functions implemented in on-chip electrowetting operations. The current status of this EWD toolkit is discussed. However, the question remains: which applications can be performed on a digital microfluidic platform? And, are there other advantages offered by electrowetting technology, such as the programming of different fluidic functions on a common platform (reconfigurability)? To understand the opportunities and limitations of EWD microfluidics, this paper looks at the development of lab-on-chip applications in a hierarchical approach. Diverse applications in biotechnology, for example, will serve as the basis for the requirements for electrowetting devices. These applications drive a set of biomedical fluidic functions required to perform an application, such as cell lysing, molecular separation, or analysis. In turn, each fluidic function encompasses a set of elemental operations, such as transport, mixing, or dispensing. These elemental operations are performed on an elemental set of components, such as electrode arrays, separation columns, or reservoirs. Examples of the incorporation of these principles in complex biomedical applications are described.
1,094 citations
"An impressive approach for incorpor..." refers background or methods in this paper
...This device is usually known as DMFB (Digital Microfluidic Biochip) [1,2,5,6,9] (or DMFS (Digital Microfluidic System))....
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...This very small amount of liquid acts on the principle of modulating the interfacial tension between a liquid and an electrode coated with a dielectric layer of insulation [9]....
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...The name of the device DMFB is commonly known as ElectroWetting-on-Dielectric (EWOD) toolkit [9]....
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...Besides, the guard band is a row of cells that usually does not help to route droplets but used for secured movement of droplets [5,6,9] irrespective of whether the paths for movement of droplets are predefined....
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...Some of the characteristics of such a device are higher throughput, minimal human intervention, higher sensitivity, smaller sample / reagent consumption, and increased productivity [6,9,14]....
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TL;DR: This paper studies the effects of varying droplet aspect ratios on linear-array droplet mixers, and proposes mixing strategies applicable for both high and low aspect ratio systems, and presents a split-and-merge mixer that takes advantage of the ability to perform droplet splitting at these ratios.
Abstract: The mixing of analytes and reagents for a biological or chemical lab-on-a-chip is an important, yet difficult, microfluidic operation. As volumes approach the sub-nanoliter regime, the mixing of liquids is hindered by laminar flow conditions. An electrowetting-based linear-array droplet mixer has previously been reported. However, fixed geometric parameters and the presence of flow reversibility have prevented even faster droplet mixing times. In this paper, we study the effects of varying droplet aspect ratios (height ∶ diameter) on linear-array droplet mixers, and propose mixing strategies applicable for both high and low aspect ratio systems. An optimal aspect ratio for four electrode linear-array mixing was found to be 0.4, with a mixing time of 4.6 seconds. Mixing times were further reduced at this ratio to less than three seconds using a two-dimensional array mixer, which eliminates the effects of flow reversibility. For lower aspect ratio (≤0.2) systems, we present a split-and-merge mixer that takes advantage of the ability to perform droplet splitting at these ratios, resulting in a mixing time of less than two seconds.
491 citations
Additional excerpts
...Accordingly, mixer size also vary like 1×2, 1×3, 2×2, 2×3, 2×4 [12,13,15], etc....
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TL;DR: In this paper, an alternative mixing strategy is presented based on the discretization of liquids into droplets and further manipulation of those droplets by electrowetting, where interfacial tensions of the droplets are controlled with the application of voltage.
Abstract: Mixing of analytes and reagents is a critical step in realizing a lab-on-a-chip. However, mixing of liquids is very difficult in continuous flow microfluidics due to laminar flow conditions. An alternative mixing strategy is presented based on the discretization of liquids into droplets and further manipulation of those droplets by electrowetting. The interfacial tensions of the droplets are controlled with the application of voltage. The droplets act as virtual mixing chambers, and mixing occurs by transporting the droplet across an electrode array. We also present an improved method for visualization of mixing where the top and side views of mixing are simultaneously observed. Microliters of liquid droplets are mixed in less than five seconds, which is an order of magnitude improvement in reported mixing times of droplets. Flow reversibility hinders the process of mixing during linear droplet motion. This mixing process is not physically confined and can be dynamically reconfigured to any location on the chip to improve the throughput of the lab-on-a-chip.
380 citations