scispace - formally typeset
Search or ask a question
Author

Jun Zeng

Bio: Jun Zeng is an academic researcher from Hewlett-Packard. The author has contributed to research in topics: Service provider & Service (business). The author has an hindex of 12, co-authored 88 publications receiving 1011 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: This study shows that both electrowetting on dielectric and dielectrophoresis are effective for droplet generation and manipulation, and demonstrates: (1) the presence of a wetting contribution to dielectophoresis; and (2) contact angle reduction is merely an observable consequence of, not a condition for, the occurrence of electrowsetting onDielectric.
Abstract: Electrically controlled droplet-based labs-on-a-chip operate under the principles of electro-capillarity and dielectrophoresis. The microfluidic mechanics of manipulating electrified droplets are complex and not entirely understood. In this article, we analyse these operating principles, especially electrowetting on dielectric (a form of electro-capillarity) and dielectrophoresis, under a unified framework of droplet electrohydrodynamics. We differentiate them by their electric origins and their energy transduction mechanisms. Our study shows that both electrowetting on dielectric and dielectrophoresis are effective for droplet generation and manipulation. In addition, our study demonstrates: (1) the presence of a wetting contribution to dielectrophoresis; and (2) contact angle reduction is merely an observable consequence of, not a condition for, the occurrence of electrowetting on dielectric. Simulations are used extensively in this article to illustrate device operation, to expose underlying physics, and to validate our conclusions. Simulations of electrically driven droplet generation, droplet translocation, droplet fusion, and droplet fission are presented.

310 citations

Journal ArticleDOI
TL;DR: Different actuation mechanisms for microfluidics-based biochips, as well as associated design automation trends and challenges are presented, and the underlying physical principles of eletrokinetics, electrohydrodynamics, and thermo-capillarity are discussed.
Abstract: Advances in microfluidics technology offer exciting possibilities in the realm of enzymatic analysis, DNA analysis, proteomic analysis involving proteins and peptides, immunoassays, implantable drug delivery devices, and environmental toxicity monitoring. Microfluidics-based biochips are therefore gaining popularity for clinical diagnostics and other laboratory procedures involving molecular biology. As more bioassays are executed concurrently on a biochip, system integration and design complexity are expected to increase dramatically. This paper presents different actuation mechanisms for microfluidics-based biochips, as well as associated design automation trends and challenges. The underlying physical principles of eletrokinetics, electrohydrodynamics, and thermo-capillarity are discussed. Next, the paper presents an overview of an integrated system-level design methodology that attempts to address key issues in the modeling, simulation, synthesis, testing and reconfiguration of digital microfluidics-based biochips. The top-down design automation will facilitate the integration of fluidic components with microelectronic component in next-generation system-on-chip designs.

101 citations

Journal ArticleDOI
TL;DR: The droplet-based “digital” microfluidic technology platform and emerging applications are described, and computer-aided design tools for simulation, synthesis and chip optimization are presented.
Abstract: Microfluidics-based biochips enable the precise control of nanoliter volumes of biochemical samples and reagents. They combine electronics with biology, and they integrate various bioassay operations, such as sample preparation, analysis, separation, and detection. Compared to conventional laboratory procedures, which are cumbersome and expensive, miniaturized biochips offer the advantages of higher sensitivity, lower cost due to smaller sample and reagent volumes, system integration, and less likelihood of human error. This paper first describes the droplet-based “digital” microfluidic technology platform and emerging applications. The physical principles underlying droplet actuation are next described. Finally, the paper presents computer-aided design tools for simulation, synthesis and chip optimization. These tools target modeling and simulation, scheduling, module placement, droplet routing, pin-constrained chip design, and testing.

84 citations

Patent
24 Oct 2011
TL;DR: In this paper, a cloud-based infrastructure provides a simulation service accessible by a plurality of different enterprises, where the operation simulation is of a business process of a particular enterprise and uses information provided by the particular enterprise.
Abstract: A cloud-based infrastructure provides a simulation service accessible by a plurality of different enterprises. The cloud-based infrastructure executes an operation simulation in response to access of the simulation service by a particular one of the plurality of enterprises, wherein the operation simulation is of a business process of the particular enterprise and uses information provided by the particular enterprise.

78 citations

Proceedings ArticleDOI
07 Nov 2010
TL;DR: In this paper, the authors provide an overview of microfluidic biochips and describe emerging computer-aided design tools for the automated synthesis and optimization of bio-chips, from physical modeling to fluidic-level synthesis and then to chip-level design.
Abstract: Advances in droplet-based digital microfluidics have led to the emergence of biochips for automating laboratory procedures in biochemistry and molecular biology. These devices enable the precise control of microliter of nanoliter volumes of biochemical samples and reagents. They combine electronics with biology, and integrate various bioassay operations, such as sample preparation, analysis, separation, and detection. Compared to conventional laboratory procedures, which are cumbersome and expensive, miniaturized digital microfluidic biochips (DMFBs) offer the advantages of higher sensitivity, lower cost, system integration, and less likelihood of human error. This tutorial paper provides an overview of DMFBs and describes emerging computer-aided design (CAD) tools for the automated synthesis and optimization of biochips, from physical modeling to fluidic-level synthesis and then to chip-level design. By efficiently utilizing the electronic design automation (EDA) technique on emerging CAD tools, users can concentrate on the development of nanoscale bioas-says, leaving chip optimization and implementation details to design-automation tools.

76 citations


Cited by
More filters
01 Jan 2002

9,314 citations

Journal ArticleDOI
TL;DR: In this paper, the authors compare the various approaches used to derive the basic electrowetting equation, which has been shown to be very reliable as long as the applied voltage is not too high.
Abstract: Electrowetting has become one of the most widely used tools for manipulating tiny amounts of liquids on surfaces. Applications range from 'lab-on-a-chip' devices to adjustable lenses and new kinds of electronic displays. In the present article, we review the recent progress in this rapidly growing field including both fundamental and applied aspects. We compare the various approaches used to derive the basic electrowetting equation, which has been shown to be very reliable as long as the applied voltage is not too high. We discuss in detail the origin of the electrostatic forces that induce both contact angle reduction and the motion of entire droplets. We examine the limitations of the electrowetting equation and present a variety of recent extensions to the theory that account for distortions of the liquid surface due to local electric fields, for the finite penetration depth of electric fields into the liquid, as well as for finite conductivity effects in the presence of AC voltage. The most prominent failure of the electrowetting equation, namely the saturation of the contact angle at high voltage, is discussed in a separate section. Recent work in this direction indicates that a variety of distinct physical effects?rather than a unique one?are responsible for the saturation phenomenon, depending on experimental details. In the presence of suitable electrode patterns or topographic structures on the substrate surface, variations of the contact angle can give rise not only to continuous changes of the droplet shape, but also to discontinuous morphological transitions between distinct liquid morphologies. The dynamics of electrowetting are discussed briefly. Finally, we give an overview of recent work aimed at commercial applications, in particular in the fields of adjustable lenses, display technology, fibre optics, and biotechnology-related microfluidic devices.

1,962 citations

Journal ArticleDOI
TL;DR: The analysis of time series: An Introduction, 4th edn. as discussed by the authors by C. Chatfield, C. Chapman and Hall, London, 1989. ISBN 0 412 31820 2.
Abstract: The Analysis of Time Series: An Introduction, 4th edn. By C. Chatfield. ISBN 0 412 31820 2. Chapman and Hall, London, 1989. 242 pp. £13.50.

1,583 citations

01 Jan 1994
TL;DR: Micromachining technology was used to prepare chemical analysis systems on glass chips that utilize electroosmotic pumping to drive fluid flow and electrophoretic separation to distinguish sample components with no moving parts.
Abstract: Micromachining technology was used to prepare chemical analysis systems on glass chips (1 centimeter by 2 centimeters or larger) that utilize electroosmotic pumping to drive fluid flow and electrophoretic separation to distinguish sample components. Capillaries 1 to 10 centimeters long etched in the glass (cross section, 10 micrometers by 30 micrometers) allow for capillary electrophoresis-based separations of amino acids with up to 75,000 theoretical plates in about 15 seconds, and separations of about 600 plates can be effected within 4 seconds. Sample treatment steps within a manifold of intersecting capillaries were demonstrated for a simple sample dilution process. Manipulation of the applied voltages controlled the directions of fluid flow within the manifold. The principles demonstrated in this study can be used to develop a miniaturized system for sample handling and separation with no moving parts.

1,412 citations

Journal ArticleDOI
Richard B. Fair1
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