Fluidic diode

Microfluidic Control Sequential and combinatorial delivery of signals to cells or tissue in microfluidic devices can be accomplished by using built-in control systems. Several microfluidic tools including valves, pumps, mixers, fluidic oscillators, fluidic diodes, etc. have been developed to accomplish fluidic control in these devices. These components can either be passive or active. Examples of passive elements include one-way valves (flap, ball) and hydrophobic patohes which take advantage of the interactiOTi between the chemical surface properties of the substrate and Uquid. Active elements, on the other hand, typically require some type of actuation mechanism. Several mechanisms for force transduction in microfluidic devices include mechanical, thermal, electrical, magnetic, and chemical actuation systems as well as the use of biological transducers. There has been a significant amount of work in this area that has been presented in a review by Erickson and Li [5]. 

Valve-Less Rectification Pumps, Fig. 7 Schematic representation of the double-acting reciprocating pump driven by a full-bridge two-phase actuator. Two alternating flows, mutually phase-shifted by n radians, are rectified by four fluidic diodes coimected to form the Gratz... 

The performance criterion of fluidic diodes is diodity - the ratio of dissipances [18]. 

Valve-Less Rectification Pumps, Fig. 16 Tesla diode, the earliest no-moving-part device designed to exhibit a large difference between the properties in forward and return flow direction. While the forward flow left, top) is almost straight, the reverse flow right, bottom) enters the complex curved flowpath. Diodity, even in the typical multi-stage layout, is not high, much worse than obtainable with vortex-type fluidic diodes... 

Kordik J, Travnicek Z (2012) Novel Fluidic Diode for Hybrid Synthetic Jet Actuator. J Fluids Eng 135 101101-1... 

A version of a no-moving-part fluidic diode consisting of two series-connected components a flow contraction upstream and a diffuser immediately downstream. 

It is a successful type of fluidic diode particularly suited for operation at quite high operating frequencies. Its operation may be explained by considering the difference in the widths or diameters of the issuing jets in the two opposing flow directions. The difference is due to the flow separation from the walls of the contraction, which lacks the diffuser property of keeping the flow attached. 

A type of a no-moving-part fluidic diode, the essential part of which is an axisymmetric chamber with tangential inlet and axial outlet. 

A fluidic diode based on the difference in fluid flow between the situations with fluid entering the... 

Fluidic diodes and vortex valves are passive devices whose use in future nuclear power plants (NPPs) is currently under evaluation with reference to their potential use as check valves or actuation valves in safety-related systems. Fluidic diodes, used in reprocessing plants and chemical industries, are one-way valves with no moving parts. They are characterized by a very high flow resistance in one... 

Valve-Less Rectification Pumps, Rgure 1 Schematic representation of a single-action reciprocating pump. The alternating flow, shown symbolically as generated by a piston and crankshaft mechanism, is rectified by two fluidic diode valves. Their schematic symbol is derived from one of the oldest... 

In the valve-less pumps, the mechanofluidic one-way valves are replaced by fluidic diodes. A diode is a device exhibiting different hydrodynamic properties for different directions of the flow. The effect is characterized by diodity - the ratio of dissipances... 

A fluidic diode based on the difference in fluid flow between the situations with fluid entering the chamber tangentially a producing there a rotation and with the fluid entering axially, when the rotation is absent. This type of... 

The FIM analyzer is fully planar organized by packaging the four main modules on a Si-glass wafer stmcture with a network of microfluidic channels Fig 1 shows this configuration for a FIM prototype realized on a 4 inch Si wafer with 8 x ISFETs, 2x2 fluidic injectors and 2 x fluidic diodes The number of modules and their configuration are flexibly defined to meet different analysis tasks The modules microactuators,... 

Electrical interconnections are made both by conductive adhesives and wire bonding The fluid handling is accomplished by means of piezoelectric micro fluidic injectors and micro fluidic diodes The function principle is explained in section 3 The main electronic functions are implemented on a programmable ASIC... 

Flmd-injectOT acting as valve and fluidic diode... 

The fluid injector is made from <100>-silicon and consists of a pump chamber with several in- and outlets A micro sieve with defined mesh size is used as a fluidic diode The outlet of the injector is separated from the micro sieve by an air space (see Fig 3 - left) so that in the off-state of the actuator the fluid 1 is kept totally decoupled from the carrier fluid 2 As to be seen in Fig 3 by computer-animation liquid-drops are injected to the carrier fluid without the carrier passes the sieve upward If the flow of the carrier is suppressed at the same time the injected drops will form a liquid volume below the sieve In this way, the fluid dosing can be performed without any leakage, even in the nl range The volume of the drop shown m Fig 3 (left) is about 1 5 nl The piezo-actuator (PZT-ceramic, 100 pm thick) is supplied with 30 100 V rectangular pulses The upper limit of the frequency is approximately 2 kHz... 

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