The deflection of the elastic sheet may constrict the interior surface of the lumen and provide a sequential squeezing action to force fluid through the lumen. FIG. 3C illustrates the deflection of the lower surface 132 of the active area 130 toward the upper substrate surface 104. As illustrated in FIG. FIG. SA illustrates the device in exploded view. FIG. 3 illustrates an example of the inventive device as described above. FIG. 4B schematically illustrates in cross-sectional side view along dotted line A the device in an unactuated configuration. 1-5 illustrates a device, wherein the upper surface of the substrate is substantially planar. Depending on the construction of the device, actuation may result in the active area being deflected toward or away from the upper substrate surface. After actuation, the lower surface 132 of the active area 130 is deflected away from the upper surface 104 of the substrate 102. As illustrated in FIG.
1, illustrate a version of the inventive device, wherein an active area of elastic sheet, after actuation, is deflected away from a substrate surface to form a conduit extending along the length of the substrate. To ensure that the upper surface of the active area cannot be deflected away from the substrate, an optional rigid cover plate (not shown) may be provided over at least the upper surface of active area of the elastic sheet.
In more preferred instances, the active area may be deflected away from the substrate through a linear strain of at least about 50 percent. The elastic sheet has a plurality of active areas each at least partially contained between two immobilization points. In another embodiment, a device is provided that comprises a substrate and an elastic sheet immobilized with respect thereto at a minimum of two immobilization points, wherein the elastic sheet has an active area at least partially contained between the immobilization points and two electrodes in contact with the active area such that fluid may flow between the active area and an upper surface of the substrate. That is, at least one electrode is located at the upper surface of the elastic sheet, and at least one electrode is located at the lower surface of any of the active areas.
Dolores Musculares Generalizados
The term “active area” as used herein refers to a portion of an elastic sheet having at least a lower surface that is mobile with respect to the substrate. Preferably the entire elastic sheet, except for the active area, is immobilized with respect to the substrate. Dolor muscular espalda alta izquierda . For the above-described embodiments as well as various embodiments described below, it is important to ensure that the lower surface of the active layer does not adhere or “stick” to the upper surface of the substrate. In other instances, a non-stick coatings may be applied to contacting surfaces (e.g., upper surface 104 and/or lower surface 132 in FIGS. Microchambers, as another example, may have a volume of about 1 nl to about 100 μl, typically about 10 nl to 20 μl. Electrophoresis, another electrokinetic phenomenon, may also occur in the channels.
Dolor De Muelas
Because microfluidic devices may be constructed using simple manufacturing techniques, they are generally inexpensive to produce. All elastic sheet materials used may be chemically inert and physically stable with respect to any substance with which they come into contact during use (e.g., with respect to pH, ion concentration, etc.). Each of the methods involves providing a device comprising a substrate and an elastic sheet immobilized with respect thereto at a minimum of two immobilization points.
The term “conduit” as used herein refers to a three-dimensional enclosure formed by one or more walls and having an inlet opening and an outlet opening through which fluid may be transported. The device 110 also includes an elastic sheet 120 having lower and upper opposing surfaces indicated at 122 and 124, respectively, arranged over the substrate 102. Located on the lower surface 122 of the elastic sheet is a fluid-transporting feature in the form of a channel 125 extending along the length of the elastic sheet.
Dolor Espalda Al Respirar
However, elastic materials having a Young’s modulus outside of these ranges may also be employed when needed for a particular application. To allow actuation of all of the active areas through the application of an electric field, the total number of electrodes for the device may be equal to or greater than one plus the number of active areas on the elastic sheet. Thus, the invention provides a number of methods for controlling fluid flow.
When the elastic sheet is comprised of a polymer, the polymer is preferably comprised of one or more elastomers. While not wishing to be bound by theory, elastomers are typically said to be polymers that exist at a temperature between their glass transition temperature and their liquefaction temperature. 2000), “High-Speed Electrically Actuated Elastomers with Strain Greater than 100%,” Science 287:836-839, as well as in a number of PCT publications. Typically, microfluidic systems miniaturize and automate a number of laboratory processes that are then integrated on a chip. Dolor en el dedo corazon de la mano . A number of techniques may be employed to reduce or eliminate the potential for such adhesion. In addition, the upper surface of the device may represent an exterior surface of cylindrical substrate. For example, FIGS. 1 and 2 each illustrate a fluid flow control device wherein the upper surface of the elastic sheet represents an exterior surface of the device. 5B, the lower surface 122 of the elastic sheet 120, in combination with the channel 108, defines a conduit 126 and provides a fluid-tight seal against the upper surface opening 116 of the conduit 114. Thus, conduit 114 and 126 are fluidly isolated from each other, while termini 110 and 112 fluidly communicate with each other.
The medium may also comprise ionized gases, inert gases and liquids (supercritical or otherwise.
In addition, the lower surface 122 of the elastic sheet 120, when in an unactuated state, provides a fluid-tight seal against the upper surface opening of the substrate. In one method, for example, the lower surface of the active area of the elastic sheet, prior to actuation, is in fluid-tight contact with an upper surface of the substrate. FIGS. 2B and 2C schematically illustrate in cross-sectional side view along dotted line A the device before and after actuation, respectively. The medium may also comprise ionized gases, inert gases and liquids (supercritical or otherwise. Instead, the lower surface of the active area, in combination with the upper surface of the substrate, defines a fluid-transporting feature 136 that provides fluid communication between the conduits 114 and 126. In other words, fluid may now be conducted in a flow path that extends in order through conduit 126, fluid-transporting feature 136, opening 116, conduit 114, and opening 118. The fluid-transporting feature may be formed, for example, as a conduit or as a chamber.
Dolor Espalda Alta Causas
The elastic sheet may be comprised of an electroactive polymer attached to the upper surface of the substrate and arranged in such a manner as to cause the polymer in the active area to deflect in response to a change in electric field. For example, a nonmechanical means may be adapted to apply an electric field to the active area. An electric potential is then applied to the electrodes, which deflects the active area toward the upper surface of the substrate such that fluid-tight contact is achieved between the surfaces. In some instances, proper selection of substrate and elastic sheet material will prevent uncontrolled adhesion between the surfaces. Dolor de cadera y rodilla . An electric potential is applied to the electrodes to deflect the active area toward the upper surface of the substrate such that fluid-tight contact is achieved between the surfaces. In some instances, however, a fluid-transporting feature may be formed by the combination of the upper substrate surface and the lower surface of the active area before actuation.
Dolor De Cabeza
Fluid-transporting features include, but are not limited to, chambers, reservoirs, conduits, and channels. The features of the microdevices are adapted to the particular use of the microfluidic device. No. 6,117,396 to Demers describes a device for delivering defined volumes of a liquid. Thus, for example, reference to “an active area” includes a plurality of active areas, reference to “a immobilization point” includes a locus of immobilization points, reference to “a feature” includes a plurality of features, and the like. Further, as described above, the sample microchannel 108 can assume a wide variety of possible channel geometries, including semi-circular, rectangular, rhomboidal, trapezoidal, circular, ellipsoidal, parabolic, hyperbolic, and polygonal, as well as sections of the above shapes.
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- Mes de gestación
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- Intoxicación alimentaria
- The apparatus of claim 63, further comprising
A low modulus of elasticity, of no more than about 108 Pa, is preferred. In addition, the substrate typically should have a rigidity of about 10 times that of the elastic sheet. The channels can assume a wide range of aspect ratios. This process allows the development of highly precise channels with dimensions that can be varied in their width and depth. In cases wherein the substrate represents a component of a microfluidic device, the substrate must be fabricated from a material that enables formation of high definition (or high “resolution”) features of micrometer or submicrometer dimensions, e.g., microchannels, chambers, and the like. Generally, on the microfluidic scale, small amounts of pressure may produce predictable and reproducible fluid flow through microfluidic fluid-transporting features. Microfluidic technologies, in particular, have recently captured widespread attention in the fields of biological assays, clinical diagnostics, and synthetic and analytical chemistry. In such systems, a noncontact electrode communicates charge to or from a portion of the polymer.