A Design of Digital Microfluidic Biochip along with Structural and Behavioural Features in Triangular Electrode Based Array

AbstractDigital microfluidic based biochip manoeuvres on the theory of microfluidic technology, having a broad variety of applications in chemistry, biology, environmental monitoring, military etc. Being concerned about the technological advancement in this domain, we have focused on equilateral triangular electrodes based DMFB systems. Accepting the associated design issues, here, we have addressed many facets of such electrodes regarding their structural and behavioural issues in comparison to the existing square electrodes. As the requisite voltage reduction is a key challenging design issues, to implement all the tasks using triangular electrodes that are possible in square electrode arrays as well, is a tedious job. Furthermore, to deal with this new design deploying triangular electrodes, we have analyzed all the necessary decisive factors including fluidic constraints to ensure safe droplet movements and other modular operations together with mixing and routing. Moreover, an algorithm has been developed to find a route for a given source and destination pair in this newly designed DMFB. Finally, we have included a comparative study between this new design and the existing one while encountering the above mentioned issues

Design practices used in the development of microfluidic devices: a services-based view

This paper presents the current state of microfluidic design from a practitioner’s perspective. The capture of microfluidic design practice was facilitated through a combination of industry survey and expert interviews, allowing the authors to draw out models for microfluidic design. Exploration of the current practice of microfluidic design showed that formal design methodologies were not in use. This research has also found that sub-section interactions have been addressed in an inadequate fashion by current design practices. The work presented in this paper outlines the scope for further research in the development of a formal design methodology for microfluidics

Three-dimensional digital microfluidic manipulation of droplets in oil medium

We here develop a three-dimensional DMF (3D DMF) platform with patterned electrodes submerged in an oil medium to provide fundamental solutions to the technical limitations of 2D DMF platforms and water-air systems. 3D droplet manipulation on patterned electrodes is demonstrated by programmably controlling electrical signals. We also demonstrate the formation of precipitates on the 3D DMF platform through the reaction of different chemical samples. A droplet containing precipitates, hanging on the top electrode, can be manipulated without adhesion of precipitates to the solid surface. This method could be a good alternative strategy to alleviate the existing problems of 2D DMF systems such as cross-contamination and solute adsorption. In addition, we ascertain the feasibility of temperature-controlled chemical reaction on the 3D DMF platform by introducing a simple heating process. To demonstrate applicability of the 3D DMF system to 3D biological process, we examine the 3D manipulation of droplets containing mouse fibroblasts in the 3D DMF platform. Finally, we show detachment of droplets wrapped by a flexible thin film by adopting the electro-elasto-capillarity ( EEC). The employment of the EEC may offer a strong potential in the development of 3D DMF platforms for drug encapsulation and actuation of microelectromechanical devices.open111416sciescopu

Coplanar Electrowetting-Induced Droplet Ejection for 3D Digital Microfluidic Devices

Digital microfluidics is a promising fluid processing technology used in lab-on-achip applications to perform chemical synthesis, particle filtration, immunoassays, and other biological protocols. Traditional digital microfluidic (DMF) devices consist of a 2D grid of coated electrodes over which droplets are manipulated. Selective activation of the electrodes results in an electrowetting effect that deforms the droplets and can move them around the electrode grid. More recently, electrowetting on dielectric has also been used to eject droplets and transfer them between opposing surfaces. This has given rise to new 3D DMF devices capable of more sophisticated routing patterns that can minimize crosscontamination between different biological reagents used during operation. A better understanding of electrowetting-induced droplet ejection is critical for the future development of efficient 3D DMF devices. The focus of this work was to better predict electrowetting-induced droplet ejection and to determine how droplet selection and electrode design influence the process. An improved model of droplet gravitational potential and interfacial energy throughout ejection was developed that predicts a critical electrowetting number necessary for successful detachment. Predictions using the new model agreed more closely with experimentally observed thresholds than previous models, especially for larger droplet volumes. Droplet ejection experiments were also performed with a variety of coplanar electrode designs featuring different numbers of electrode pieces and different spacings between features. The critical voltage for ejection was observed to be approximately the same for all designs, despite the poor predicted performance for the case with the widest spacing (200 ) where nearly 25% of the area beneath the droplet was dead space. Findings indicated that a critical electrowetting for ejection must be achieved at the contact line of a droplet rather than over the entire droplet region. Droplets were also ejected for the first time from devices with inkjet-printed electrodes, demonstrating the feasibility of future low-cost 3D DMF systems

Service-oriented design of microfludic devices

Microfluidics is a relatively new and, with an estimation of the market for these devices exceeding $3 billion in 2014, it is considered a profitable domain. Constant development of new technologies and growing demand for more versatile products cause increasing complexity in this area. To address this, the current trends for the domain include automation, standardisation and customisation. At the same time, the society is moving from product types offering to services. Due to the customisation trend this transition appears beneficial for microfluidics. Taking advantage of these opportunities, an investigation of microfluidic design has been undertaken to address the issues at their origins. The literature review showed a lack of a general design methodology applicable for all microfluidic devices, identified existing approaches as technology driven and the domain as unique in terms of design. Also, it highlighted a number of automation and standardisation attempts in the area. In addition, microfluidics shows limited customer and service-orientation. Meanwhile, an investigation of complexity and its implications in microfluidics narrowed the study to sub-section interactions, which allowed standardisation and automation without compromising customisation. In response to these gaps, an aim of the research is to develop a guideline for service- oriented design of microfluidic devices that can deal with sub-section interactions. This research reviews: existing methodologies for design in micro-scale, their applicability to the domain, microfluidic practitioners’ approach to design, state of service-thinking and services in the area and how sub-section interactions are dealt with for these devices. The developed guideline and design enablers present a proposal for a general process for the design of microfluidics. The solution attempts to tackle the issue of sub- section interactions and brings the domain one step towards an ‘experience economy’ by incorporating service-considerations into the design process. The usefulness of this contribution has been confirmed by a variety of methods and numerous sources including experts in the field.EThOS - Electronic Theses Online ServiceGBUnited Kingdo