A valveless diffuser/nozzle-based fluid pump
TL;DR: A new valveless fluid pump has been designed and tested that consists of two fluid diffuser/nozzle elements on each side of a chamber volume with an oscillating diaphragm that creates a one-way fluid flow.
Abstract: A new valveless fluid pump has been designed and tested. The pump consists of two fluid diffuser/nozzle elements on each side of a chamber volume with an oscillating diaphragm. The vibrating diaphragm produces an oscillating chamber volume, which together with the two fluid-flow-rectifying diffuser/nozzle elements, creates a one-way fluid flow. A micropump prototype with a chamber diameter of 19 mm with conical diffuser/nozzle elements has been built and tested. The maximum liquid flow rate is 16 ml/min and the maximum pump pressure is 2 m H 2 O. The pump frequency is of the order of 100 Hz.
Citations
More filters
TL;DR: A review of the physics of small volumes (nanoliters) of fluids is presented, as parametrized by a series of dimensionless numbers expressing the relative importance of various physical phenomena as mentioned in this paper.
Abstract: Microfabricated integrated circuits revolutionized computation by vastly reducing the space, labor, and time required for calculations. Microfluidic systems hold similar promise for the large-scale automation of chemistry and biology, suggesting the possibility of numerous experiments performed rapidly and in parallel, while consuming little reagent. While it is too early to tell whether such a vision will be realized, significant progress has been achieved, and various applications of significant scientific and practical interest have been developed. Here a review of the physics of small volumes (nanoliters) of fluids is presented, as parametrized by a series of dimensionless numbers expressing the relative importance of various physical phenomena. Specifically, this review explores the Reynolds number Re, addressing inertial effects; the Peclet number Pe, which concerns convective and diffusive transport; the capillary number Ca expressing the importance of interfacial tension; the Deborah, Weissenberg, and elasticity numbers De, Wi, and El, describing elastic effects due to deformable microstructural elements like polymers; the Grashof and Rayleigh numbers Gr and Ra, describing density-driven flows; and the Knudsen number, describing the importance of noncontinuum molecular effects. Furthermore, the long-range nature of viscous flows and the small device dimensions inherent in microfluidics mean that the influence of boundaries is typically significant. A variety of strategies have been developed to manipulate fluids by exploiting boundary effects; among these are electrokinetic effects, acoustic streaming, and fluid-structure interactions. The goal is to describe the physics behind the rich variety of fluid phenomena occurring on the nanoliter scale using simple scaling arguments, with the hopes of developing an intuitive sense for this occasionally counterintuitive world.
4,044 citations
Cites background from "A valveless diffuser/nozzle-based f..."
...An oscillatory flow through an asymmetric channel can drive a rectified, steady fluid motion which forms the basis for valveless diffuser pumps Stemme and Stemme, 1993; Olsson et al., 1999 ....
[...]
TL;DR: In this article, the authors survey progress over the past 25 years in the development of microscale devices for pumping fluids and attempt to provide both a reference for micropump researchers and a resource for those outside the field who wish to identify the best micropumps for a particular application.
Abstract: We survey progress over the past 25 years in the development of microscale devices for pumping fluids. We attempt to provide both a reference for micropump researchers and a resource for those outside the field who wish to identify the best micropump for a particular application. Reciprocating displacement micropumps have been the subject of extensive research in both academia and the private sector and have been produced with a wide range of actuators, valve configurations and materials. Aperiodic displacement micropumps based on mechanisms such as localized phase change have been shown to be suitable for specialized applications. Electroosmotic micropumps exhibit favorable scaling and are promising for a variety of applications requiring high flow rates and pressures. Dynamic micropumps based on electrohydrodynamic and magnetohydrodynamic effects have also been developed. Much progress has been made, but with micropumps suitable for important applications still not available, this remains a fertile area for future research.
1,913 citations
Cites methods from "A valveless diffuser/nozzle-based f..."
...1 (lateral) Stemme 1993 [91] Piezoelectric Fixed-geometry Brass 1 Brass 2500 0....
[...]
...The brass micropumps reported in 1993 by Stemme and Stemme have nozzle-diffuser inlet and outlet channel geometries that function as fixed-geometry valves [91]....
[...]
...Piezo-driven micropumps made by precision machining of brass were reported by Stemme and Stemme in 1993 [91]....
[...]
TL;DR: An overview of research activities in the field of fluid components or systems built with microfabrication technologies is given in this paper, focusing on the fluidic behaviour of the various devices, such as valves, pumps and flow sensors as well as the possibilities and pitfalls related to the modelling of these devices using simple flow theory.
Abstract: An overview is given of research activities in the field of fluid components or systems built with microfabrication technologies. This review focuses on the fluidic behaviour of the various devices, such as valves, pumps and flow sensors as well as the possibilities and pitfalls related to the modelling of these devices using simple flow theory. Finally, a number of microfluidic systems are described and comments on future trends are given.
1,153 citations
TL;DR: A brief overview of microvalves can be found in this paper, where the authors focus on the actuation mechanisms and their applications, including flow regulation, on/off switching and sealing of liquids, gases or vacuums.
Abstract: This review gives a brief overview of microvalves, and focuses on the actuation mechanisms and their applications. One of the stumbling blocks for successful miniaturization and commercialization of fully integrated microfluidic systems was the development of reliable microvalves. Applications of the microvalves include flow regulation, on/off switching and sealing of liquids, gases or vacuums. Microvalves have been developed in the form of active or passive microvalves employing mechanical, non-mechanical and external systems. Even though great progress has been made during the last 20 years, there is plenty of room for further improving the performance of existing microvalves.
908 citations
Cites background from "A valveless diffuser/nozzle-based f..."
...Converging wall direction is the positive flow direction and they are therefore denoted as nozzles, with a sharp entrance and a large tapered angle of around 70◦ [202, 204]....
[...]
TL;DR: Comparisons regarding pump size, flow rate, and backpressure will help readers to decide their proper design before starting a microfluidics project.
Abstract: Microfluidics has emerged from the MEMS-technology as an important research field and a promising market. We give an overview on one of the most important microfluidic components: the micropump. In the last decade, various micropumps have been developed. There are only a few review papers on microfluidic devices and none of them were dedicated only to micropumps. This review paper outlines systematically the pump principles and their realization with MEMS-technology. Comparisons regarding pump size, flow rate, and backpressure will help readers to decide their proper design before starting a microfluidics project. Different pump principles are compared graphically and discussed in terms of their advantages and disadvantages for particular applications
566 citations
References
More filters
TL;DR: In this article, the design and realization of two pumps based on micromachining of silicon are described, which are of the reciprocating displacement type, comprise one or two pump chambers, a thin glass pump membrane actuated by a piezoelectric disc and passive silicon check valves to direct the flow.
706 citations
TL;DR: In this article, a silicon micropump, provided with piezoelectric valves, which can be manufactured by established integrated circuit techniques is the subject of this report. And the body of the pump and the valves are made in silicon and contain piezelectric material which allows opening and closing of the valves electrically.
Abstract: A silicon micropump, provided with piezoelectric valves, which can be manufactured by established integrated circuit techniques is the subject of this report. The micropump can be used to pump liquids or gases to a higher pressure, which can be relieved through a check valve. The body of the pump and the valves are made in silicon and contain piezoelectric material which allows opening and closing of the valves electrically.
438 citations
TL;DR: In this paper, a micromachined electrohydrodynamic (EHD) injection pump is presented, which mainly consists of two facing grids, which are micro-machined from s
Abstract: A new micromachined electrohydrodynamic (EHD) injection pump is presented. The pump mainly consists of two facing grids, which are micromachined from s
214 citations
04 Feb 1992
TL;DR: A bulk micromachined membrane pump with outer dimensions of 7 mm*7 mm*2 mm and electrostatic actuation is presented and direct electrostatic forces are used for the deflection of the pump membrane.
Abstract: A bulk micromachined membrane pump with outer dimensions of 7 mm*7 mm*2 mm and electrostatic actuation is presented. The micropump consists of four silicon chips, which form two passive check valves, a pump membrane and a counterelectrode for electrostatic actuation. Direct electrostatic forces are used for the deflection of the pump membrane, which has an area of 4 mm*4 mm and a thickness of 25 mu m. The liquid to be pumped is not subjected to any electrical field. The separation between the movable membrane and the electrically isolated stator is 4 mu m. >
198 citations
TL;DR: A dual pump and a buffer pump have been integrated on a silicon wafer for chemical analyzing systems as mentioned in this paper, which realize constant and rippleless liquid flow of a small volume, with controllable flow rate of up to about 40 μl/min and maximum pumping pressure was about 1 mH2O.
Abstract: A dual pump and a buffer pump have been integrated on a silicon wafer for chemical analyzing systems These pumps realize constant and rippleless liquid flow of a small volume The controllable flow rate of the pumps was up to about 40 μl/min and the maximum pumping pressure was about 1 mH2O A sample injector made up of two three-way valves has also been fabricated with micromachining
151 citations