Fluid pumping device

Abstract

A fluid pump for pumping fluid between a fluid inlet and a fluid outlet has a chamber with an inlet and an outlet. At least one flow restriction element is provided at a flow line portion and is configured to resonate along a continuum of states between a first end state and a second end state, thereby exerting an influence on the fluid flow profile through the inlet or the outlet. At resonance, the element transitions through a range of states, each of which allows a different flow. The transition is through a range of states with different allowed flows. A driver is configured to modulate conditions in the chamber or on the at least one flow restriction element with a characteristic frequency profile, thereby causing the at least one flow restriction element to resonate between the first state and the second state at about the characteristic frequency profile.

Description

Technical Field

[0001] This disclosure pertains to the field of micropumps, particularly resonant-based micropumps. Background Technology

[0002] The following is a list of references considered relevant to the current topic:

[0003] -US6,261,066

[0004] -E. Quandt, K. Seemann, Magnetostrictive Thin Film Microflow Devices, Micro System Technologies 96, pp. 451-456, VDE-35Verlag GmbH, 1996;

[0005] -B. Bustgens et al., Micromembrane Pump Manufactured by Molding, Proc. Actuator 94; Bremen 1994, pp. 86-90, EP-A-0134614 and HTG

[0006] -Van Lintel et al., A Piezoelectric Micropump Based on Micromachining of Silicon, Sensors & Actuators 15, 1988, pp. 153-167.

[0007] -A. Olsson et al.: The First Valve-less Diffuser Gas Pump, Proceedings MEMS 97, pp. 108-113, Nagoya, Japan, 1997.

[0008] The acknowledgment of the above references in this document should not be construed as implying that these references are related in any way to the patentability of the currently disclosed subject matter. Summary of the Invention

[0009] This disclosure provides a pump configured to pump fluid over a wide range of pressures and throughputs. The pump is defined along a flow path between an inlet and an outlet, and includes a chamber downstream of the inlet and upstream of the outlet. Each of one or more flow limiting / control elements is positioned along the flow path to influence the flow profile via the inlet or outlet. Typically, the pump includes two flow limiting elements: a first flow limiting element positioned at a first location along the fluid path to influence the flow profile via the inlet, and a second flow limiting element positioned at a second location along the fluid path to influence the flow profile via the outlet. The flow limiting elements cyclically switch between a flow-allowed state range where fluid flow through the inlet or outlet is permitted and a flow-restricted state range where fluid flow through the inlet or outlet is restricted, i.e., the flow rate is less in the flow-restricted state range than in the flow-allowed state range. The state of the flow limiting element changes in response to modulation of conditions within the chamber—typically volume or pressure—resulting in the application of harmonic forces to the element. The driver is configured to apply the modulation of each condition at a selected characteristic frequency distribution, for example, to modulate the volume of the chamber in a cyclic manner between a first volume and a second volume, which in turn affects the pressure in the chamber. Pressure changes within the chamber cause the state of the flow-limiting element to change continuously in a cyclic manner, and result in a flow distribution of fluid via the inlet and outlet that produces a pumping effect.

[0010] Therefore, one aspect of this disclosure provides a fluid pumping device for pumping fluid between a fluid inlet and a fluid outlet. The fluid pumping device can have two configurations.

[0011] In a first configuration, the fluid pumping device includes a chamber that can be defined as a volumetric portion between an inlet and an outlet. The chamber includes an inlet for allowing fluid to flow into the chamber and an outlet for allowing fluid to flow out of the chamber. The pumping device also includes at least one flow-limiting element disposed at a flow line portion, and the at least one flow-limiting element is configured to resonate along a continuous state between a first final state and a second final state, thereby influencing the fluid flow rate distribution via the inlet or outlet, wherein, in one or more first state ranges, the flow rate via the inlet or outlet is less than the flow rate via the inlet or outlet in one or more second state ranges.

[0012] It should be noted that the final state can vary between one operating mode and another of the fluid pumping device. For example, the final state may be affected by the pressure conditions in the chamber, the viscosity of the fluid, or other conditions. Therefore, the final state only defines the entire range of states of the flow-limiting element under the selected operating mode.

[0013] The range can be continuous, meaning all states of the first range are consecutive. Alternatively, one range of the first states can be discontinuous with another range of the first states, separated from another range of the first states by a second range. Similarly, the second range can be continuous, meaning all states of the second range are consecutive. Alternatively, one range of the second state can be discontinuous with another range of the second state, separated from another range of the second state by a first range. The flow rate within the first range is limited to a certain extent by a limiting element, the degree of limitation of which can vary between different states of one or more first ranges, and the flow rate within the second range is greater than the flow rate within the first range, i.e., substantially allowing fluid flow.

[0014] The term "substantially permissible fluid flow" should be understood as the ratio between the flow rate through the inlet / outlet or flow line section in the first flow-restricted range and the flow rate through the inlet / outlet or flow line section in the second flow-restricted range. Specifically, the flow rate in the first flow-restricted range is at least 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or sometimes 100% less than the flow rate in the second flow-restricted range.

[0015] The driver is configured to modulate the conditions in the chamber or on at least one flow-limiting element with a characteristic frequency distribution, such that the at least one flow-limiting element resonates in a matched manner between a first final state and a second final state at approximately the characteristic frequency distribution.

[0016] As used herein, the term “about” means ±10% or sometimes ±20% of the value it refers to. For example, the term about 100 Hz refers to a range between 80 Hz and 120 Hz.

[0017] In a second configuration, the fluid pumping device includes two flow-limiting / controlling elements in flow communication with a fluid chamber arranged along a flow path, such that the chamber is downstream of a first element and upstream of a second element. A driver is configured to cyclically modulate the volume or pressure in the chamber at a driver frequency selected based on the characteristics of the flow-limiting element. Each of the two elements is configured to continuously and cyclically change its state between one or more first flow-limiting state ranges and one or more second flow-allowing state ranges in response to the cyclic modulation of the volume or pressure. The cyclical change of the state of the first element is phase-shifted to the cyclical change of the state of the second element. In some embodiments, the cyclical change of the state of the first element is inversely related to the cyclical change of the state of the second element; that is, when the first flow-limiting element is in a first state within a first state range, the second flow-limiting element is in a second state within a second state range, and vice versa. The flow-limiting elements have the same resonant frequency for both elements, and both flow-limiting elements are capable of reciprocating at the resonant frequency. The driver is configured to have approximately the resonant frequency.

[0018] The following implementation methods can be applied to any of the above-described configurations of the first aspect.

[0019] In some embodiments of the fluid pumping apparatus, the at least one flow restricting element is located at the inlet, or the at least one flow restricting element is located at a portion of the flow line that affects the distribution of fluid flow through the inlet.

[0020] In some embodiments, the fluid pumping device includes two flow restricting elements: an inlet flow restricting element and an outlet flow restricting element. The inlet flow restricting element is located at the inlet or at a flow line section that affects the distribution of fluid flow through the inlet, and the outlet flow restricting element is located at the outlet or at a flow line section that affects the distribution of fluid flow through the outlet.

[0021] It should be noted that fluid pumping devices may include more than one flow restricting element at the inlet or outlet or at any other part along the flow line that affects the flow distribution through the flow line.

[0022] In some embodiments of the fluid pumping device, the state range or state of a first flow limiting element, such as an inlet flow limiting element, is phase-shifted relative to the state range or state of a second flow limiting element, such as an outlet flow limiting element. In other words, when the first flow limiting element is in a certain state, such as a first blocking or allowing state, the second flow limiting element is in a second blocking or allowing state, which is different from the first blocking or allowing state.

[0023] In some embodiments of the fluid pumping device, the inlet flow restricting element and the outlet flow restricting element are configured to switch in opposite phases between a first state range and a second state range, that is, when one element is in the first state range, the other element is in the second state range, and when one element is in the second state range, the other element is in the first state range.

[0024] In some embodiments, the fluid pumping device includes a single first state range with respect to a first state and a single second state range with respect to a second state. The first state range is defined between a first final state and a transitional state, and the second state range is defined between the transitional state and a second final state; that is, the first state range and the second state range are continuous with each other. It should be noted that the transitional state is the state in which the limiting element switches from the first state range to the second state range, and the state in which the limiting element switches from the second state range to the first state range. The transitional state may be defined as the final state of either the first state range or the second state range.

[0025] In some embodiments of the fluid pumping device, the driver is configured to modulate the volume or pressure of the chamber with the characteristic frequency distribution.

[0026] In some embodiments of the fluid pumping device, the actuator includes a diaphragm or membrane configured to alter the properties of the diaphragm or membrane to induce the modulation of the conditions.

[0027] In some embodiments of the fluid pumping device, the driver includes a piezoelectric element configured to receive a piezoelectric distribution at the characteristic frequency distribution.

[0028] In some embodiments of the fluid pumping device, the at least one flow-limiting element is a flap or leaf-like element.

[0029] In some embodiments of the fluid pumping device, the flap is fixed at one side of its side, and the opposite free side of the flap has an edge close to a wall portion of the flow line. During resonance, the distance between the edge and the wall portion changes, thereby defining whether the flow-limiting element is in the first state range or the second state range.

[0030] In some embodiments of the fluid pumping device, the free side of the flap is configured for contactless harmonic oscillation.

[0031] In some embodiments of the fluid pumping device, the fluid line portion is defined by a circumferential wall having a longitudinal cross-sectional profile, the at least one flow restricting element spanning at least a portion of the longitudinal cross-sectional profile and rotatable about an axis between a first rotational position and a second rotational position, a stationary and neutral position being defined between the first and second rotational positions, the first state being defined at a range of rotational positions between the stationary position and the first portion, and the second state being defined at a range of rotational positions between the stationary position and the second portion; or, the first state being defined at a range of rotational positions between the stationary position and the second portion, and the second state being defined at a range of rotational positions between the stationary position and the first portion.

[0032] In some embodiments of the fluid pumping apparatus, the fluid line portion has a varying longitudinal cross-sectional profile, and the at least one flow-limiting element spans at least a portion of the longitudinal cross-sectional profile and is deformable to define one or more first state ranges and one or more second state ranges.

[0033] In some embodiments of the fluid pumping device, the at least one flow-limiting element oscillates harmonicly between a first rotational position and a second rotational position, and a stationary and neutral position is defined between the first rotational position and the second rotational position. The first state is defined at a rotational position within a certain range between the stationary position and a first portion, and the second state is defined at a rotational position within a certain range between the stationary position and the second portion, or the first state is defined at a rotational position within a certain range between the stationary position and the second portion, and the second state is defined at a rotational position within a certain range between the stationary position and the first portion.

[0034] In some embodiments of the fluid pumping apparatus, the at least one flow-limiting element oscillates harmonicly between deformable states that define one or more first state ranges and one or more second state ranges.

[0035] In some embodiments of the fluid pumping device, the harmonic resonant oscillation of the at least one flow-limiting element is non-contact. That is, throughout the oscillation distribution, the at least one flow-limiting element oscillates around the axis without contacting other walls or elements.

[0036] In some embodiments of the fluid pumping device, the first state is defined by limiting the fluid flow rate by at least 50% relative to the second state, or by limiting the fluid flow rate by at least 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or sometimes 100% relative to the second state.

[0037] Another aspect of this disclosure provides a method for generating fluid pressure. The method includes modulating conditions in a chamber having a fluid inlet and a fluid outlet with a characteristic frequency distribution. The fluid flow rate via at least one of the fluid inlet and fluid outlet is controlled by at least one fluid limiting element, and the modulation causes the at least one flow limiting element to resonate continuously and in a matched manner between a first final state and a second final state. In one or more first state ranges, the flow rate via the inlet or outlet is less than the flow rate via the inlet or outlet in one or more second state ranges. That is, the first state range substantially restricts fluid flow through the inlet or outlet, while the second state range allows fluid flow through the inlet or outlet.

[0038] In some embodiments of the method, the fluid flow rate through the inlet is controlled by an inlet fluid limiting element, and the fluid flow rate through the outlet is controlled by an outlet fluid limiting element.

[0039] In some embodiments of this method, the state range or state of the first flow restricting element, such as the inlet flow restricting element, is phase-shifted relative to the state range or state of the second flow restricting element, such as the outlet flow restricting element. In other words, when the first flow restricting element is in a certain state, such as a first blocking or allowing state, the second flow restricting element is in a second blocking or allowing state, which is different from the first blocking or allowing state.

[0040] In some embodiments of the method, the inlet flow restricting element and the outlet flow restricting element are configured to switch in an inverse manner between a first state range and a second state range. That is, when one element is in the first state, the other element is in the second state, and vice versa.

[0041] In some embodiments of the method, modulation includes modulating the volume or pressure of the chamber.

[0042] In some embodiments of the method, the at least one flow-limiting element oscillates harmonicly between deformable states that define one or more first state ranges and one or more second state ranges.

[0043] In some embodiments of the method, the at least one flow-limiting element oscillates harmonic resonance between a first rotational position and a second rotational position, and a stationary and neutral position is defined between the first rotational position and the second rotational position. The first state is defined at a rotational position within a certain range between the stationary position and a first portion, and the second state is defined at a rotational position within a certain range between the stationary position and the second portion, or the first state is defined at a rotational position within a certain range between the stationary position and the second portion, and the second state is defined at a rotational position within a certain range between the stationary position and the first portion.

[0044] In some embodiments of the method, the harmonic resonant oscillation of the at least one flow-limiting element is non-contact. That is, throughout the oscillation distribution, the at least one flow-limiting element oscillates around the axis without contacting other walls or elements.

[0045] In some embodiments of the method, the first state range limits the fluid flow rate by at least 30% relative to the second state range, or limits the fluid flow rate by at least 40%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or sometimes 100% relative to the second state.

[0046] Another aspect of this disclosure provides a pressure-responsive valve including a valve chamber defined by a chamber wall having an opening that interconnects the chamber with an ambient fluid; and a valve disc configured to undergo continuous resonance, thereby alternately opening the opening and at least partially blocking the opening.

[0047] In some embodiments of the pressure-response valve, the flap has a distal portion configured to move partially parallel to the chamber wall; the distal portion has an orifice such that vibrations of the flap in response to pressure changes within the chamber alternately align the orifice with the opening to allow fluid communication between the valve chamber and the environment, and move the orifice away from the opening to block fluid communication between the valve chamber and the environment.

[0048] Another aspect of this disclosure provides a pressure-responsive valve comprising a valve chamber defined by a chamber wall having one or more openings that fluidly interconnect the chamber with an external environment; and a valve disc configured to resonate and vibrate resonantly to sequentially open each of the one or more openings and at least partially block each of the one or more openings.

[0049] In some embodiments of the pressure-response valve, the valve disc has a distal portion configured to move partially parallel to the chamber wall; the distal portion has an orifice such that vibrations of the disc in response to pressure changes within the chamber sequentially align the orifice with a first of a plurality of openings to allow fluid communication through the first opening, and move the orifice to be misaligned with the first opening to block fluid communication through the first opening, while simultaneously aligning the orifice with a second of the plurality of openings to allow fluid communication through the second opening.

[0050] Another aspect of this disclosure provides a valve disposed at a flow line section for controlling the flow distribution through said flow line section. The valve includes at least one flow restricting element configured to continuously switch between one or more first state ranges and one or more second state ranges, wherein in said one or more first state ranges, the flow rate via an inlet or outlet is less than the flow rate via an inlet or outlet in said one or more second state ranges.

[0051] In some embodiments of the valve, the at least one flow-limiting element is configured to resonate along a continuous state between a first final state and a second final state, defining one or more first state ranges and one or more second state ranges between the first final state and the second final state.

[0052] In some embodiments, the valve includes a single first state range with respect to a first state and a single second state range with respect to a second state, wherein the first state range is defined between a first final state and a transition state, and the second state range is defined between the transition state and a second final state.

[0053] In some embodiments of the valve, the at least one flow-limiting element is a flap or leaf-shaped element.

[0054] In some embodiments of the valve, the flap is fixed at one side and the opposite free side, with the edge of the free side close to the wall portion of the flow line; and at resonance, the distance between the edge and the wall portion changes, thereby defining whether the flow restricting element is in the first state range or the second state range.

[0055] In some implementations of the valve, the free side of the valve disc is configured for contactless harmonic oscillation.

[0056] In some embodiments of the valve, the fluid line portion has a varying longitudinal cross-sectional profile, and the at least one flow-limiting element spans at least a portion of the longitudinal cross-sectional profile and is deformable to define one or more first state ranges and one or more second state ranges.

[0057] In some embodiments of the valve, the at least one flow-limiting element oscillates harmonicly between deformable states that define one or more first state ranges and one or more second state ranges.

[0058] In some implementations of the valve, the first state is defined by limiting the fluid flow rate by at least 30% relative to the second state. Attached Figure Description

[0059] To better understand the subject matter disclosed herein and to illustrate how it can be implemented in practice, implementation methods will now be described by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0060] Figures 1A to 1C This is a schematic longitudinal cross-section of an example embodiment of a fluid pumping apparatus according to one aspect of this disclosure;

[0061] Figure 2 This is a schematic diagram illustrating different states of the flow-limiting element of this disclosure in a longitudinal cross-section;

[0062] Figure 3 This is a schematic diagram illustrating a longitudinal cross-section of the geometric profile of the flow-limiting element of this disclosure;

[0063] Figure 4 This is a cross-sectional view of a cylindrical valve with an oscillating piston according to one aspect of the present disclosure;

[0064] Figure 5 This is an isometric view of a cylindrical valve with an oscillating piston according to one aspect of the present disclosure;

[0065] Figure 6 This is a schematic diagram of a check valve according to one aspect of the present disclosure;

[0066] Figure 7 This is a schematic diagram of a two-way valve according to one aspect of the present disclosure;

[0067] Figure 8 This is a block diagram of a valve according to one aspect of the present disclosure; and

[0068] Figure 9 This is a flowchart of a method for controlling fluid flow according to an embodiment of one aspect of this disclosure. Detailed Implementation

[0069] Reference Figures 1A to 1C , Figures 1A to 1C This is a schematic diagram of a longitudinal section of a non-limiting example of a pump according to one aspect of this disclosure.

[0070] Figure 1A A pump 100 is shown, having a housing 10 defining a pump chamber 20, a fluid inlet 50, and a fluid outlet 70. The pump chamber 20 is defined downstream of the fluid inlet 50 and upstream of the fluid outlet 70. An inlet flow restrictor 40 is provided at a first flow path portion 110 to control the inflow of fluid into the chamber 20 via a flow line portion 42. An outlet flow restrictor 60 is provided at a second flow path portion 120 to control the outflow of fluid from the chamber 20 via the flow line portion 62. Each of the inlet flow restrictor 40 and the outlet flow restrictor 60 is configured to oscillate continuously between a first final state 40o / 60o and a second final state 40i / 60i (the first and second final states are shown in dashed lines), wherein a transition state 43 / 63—optionally a static, neutral state—is defined between the first final state 40o / 60o and the second final state 40i / 60i. The inlet flow restricting element 42 and the outlet flow restricting element 62 are configured to: (i) rotate about an axis defined by the attachment profile from the restricting element to the housing, thereby allowing oscillation between a first position and a second position; or (ii) elastically deform in response to a force applied to the inlet flow restricting element 42 and the outlet flow restricting element 62. The inlet flow restricting element 42 is capable of transitioning between at least two state ranges—namely, a first flow-allowed state range and a second flow-restricted state range. In this non-limiting example, the flow-allowed state range is defined between a transition state 43 and a second final state 40i, and the flow-restricted state range is defined between the transition state 43 and the first final state 40o. The outlet flow restricting element 62 is capable of transitioning between at least two state ranges—namely, a first flow-allowed state range and a second flow-restricted state range. In this non-limiting example, the flow-allowed state is defined between a transition state 63 and a first final state 60o, and the flow-restricted state is defined between the transition state 63 and the second final state 60i. The geometric profile of the casing wall causes transitions between states depending on the oscillating position of the flow-restricting element. Along the flow-restricted state range of the flow-restricting element, the geometric profile of wall 45 / 65 is designed to maintain a narrow gap 47 between the flow-restricting element and the wall, thereby substantially restricting flow into and out of chamber 20. Along the flow-allowed state range of the flow-restricting element, the geometric profile of the wall is designed to maintain a relatively large gap, thereby allowing unrestricted flow into and out of the chamber.

[0071] The actuator 30 is configured to modulate the volume within chamber 20 at a resonant characteristic frequency distribution between a first volume generated by a first actuator state 30o and a second volume generated by a second actuator state 30i, thereby causing the flow-limiting elements 42 / 62 to resonate in a matched manner at the characteristic frequency distribution, and thus continuously transitioning between a flow-limiting state and a flow-allowing state. In this non-limiting example, the actuator 30 includes a resonant membrane or diaphragm driven at a characteristic frequency distribution between the first actuator state 30o and the second actuator state 30i, wherein the chamber volume caused by the second actuator state 30i is smaller than the chamber volume caused by the first actuator state 30o.

[0072] The inlet flow restrictor and outlet flow restrictor typically resonate with a phase shift between them. In some embodiments, however, the flow restrictors resonate in opposite phases; that is, when the inlet flow restrictor is in a flow-restricting state, the outlet flow restrictor is in a flow-allowing state, and vice versa. See details. Figures 1B to 1C , Figures 1B to 1C The reverse operation of two flow-limiting elements is illustrated. Figure 1B The actuator is shown in a first state 30o, with the inlet flow limiting element 40 in a flow-allowed state range defined by any state between the second final state 40i and the transition state 43, and the outlet flow limiting element 60 in a flow-limited state defined by any state between the second final state 60i and the transition state 63. Figure 1C The actuator is shown in the second state 30i, with the inlet flow limiting element 40 in a flow-limited state defined by any state in the range between the first final state 40o and the transition state 43, and the outlet flow limiting element 60 in a flow-allowed state defined by any state in the range between the first final state 60o and the transition state 60.

[0073] Pump 100 operates continuously, and the state of the flow limiting elements continues to switch relative to the resonant characteristic frequency distribution. In other words, during each time period of the driver's resonant cycle, each flow limiting element switches between a first state and a second state once, and spends half of the time period in each state.

[0074] The flow-limiting element resonates harmonically around its rest position, and in a first rotational direction from the rest position, the flow-limiting element enters a flow-limiting state, and in a second rotational direction from the rest position, the flow-limiting element enters a flow-allowing state. The harmonic forces acting on the flow-limiting element—both intrinsic and extrinsic—result in the strongest forces acting at the ends of the harmonic oscillation range for each state, thus allowing very rapid transitions between states through the use of harmonic resonance effects. In some embodiments, the frequency of the actuator and / or the resonant frequency of the valve can be in the range between 1 Hz and 20 Hz and / or between 20 Hz and 100 Hz and / or between 100 Hz and 1000 Hz and / or between 1000 Hz and 10000 Hz and / or between 10000 Hz and 25000 Hz and / or between 25000 Hz and 200000 Hz. For example, the frequency of the driver and / or the resonant frequency of the valve can be within the audible frequency range of 20 Hz to 20 kHz and / or outside the audible frequency range of, for example, 25,000 Hz to 250,000 Hz.

[0075] Now refer to Figure 2 , Figure 2 This is a schematic longitudinal cross-section illustrating examples of different states of a flow-limiting element. The flow-limiting element 60 is in the form of a continuously oscillating lobe, continuously transitioning between a flow-allowing state exemplified by a first final state 60o, transitioning from a transitional state to a first side, and a flow-limiting state exemplified by a second final state 60i, transitioning from a transitional state to a second side opposite to the first side. The state of the flow-limiting element is defined by the relationship between the flow-limiting element and the geometric profile of the wall portion 65, which causes a desired gap 67 between the wall and the flow-limiting element 60, which is a relatively large gap in the flow-allowing state and a relatively narrow gap in the flow-limiting state. Figure 3 Specifically, a longitudinal section of a flow-restricting element 40 / 60 formed in a tapered manner is illustrated. Alternatively or additionally, the flaps may have a constant thickness. Alternatively or additionally, a portion of the flaps may have a constant thickness, while another portion of the flaps is tapered. For example, 0% to 10% of the flaps may be tapered, and / or 10% to 30% of the flaps may be tapered, and / or 30% to 60% of the flaps may be tapered, and / or 60% to 90% of the flaps may be tapered, and / or 90% to 100% of the flaps may be tapered. Alternatively or additionally, the tapering may be near the fixed end, and / or, the tapering may be near the free end, and / or, the tapering may be near both the fixed end and the free end (e.g., the middle portion of the flap may have a uniform thickness).

[0076] To improve the reproducibility of the lobe's resonant frequency, the lobe's mass, length, or stiffness is calibrated to match the driver's resonant frequency.

[0077] Means for adjusting the resonant frequency of the petals—such as applying an electromagnetic field to the petals in the field, using a petal retainer adjustable by screws, or changing the petal temperature in real time by a separate micro-heating element—all fall within the scope of this invention. The resonant frequency can also be adjusted using a piezoelectric actuator. The adjustment efficiency can be evaluated based on output flow and pressure monitoring data. A piezoelectric actuator can also be used for this purpose.

[0078] Now refer to Figure 4 and Figure 5 , Figure 4 and Figure 5 An embodiment of a non-contact check valve 200 is shown in a non-limiting manner. The non-contact check valve 200 includes a cylinder 210 and a valve disc in the form of a piston 220 (end positions referred to as 220i and 220o). Figures 1A to 1C Similar to the valve configuration illustrated, the gap between cylinder 210 and piston 220 is narrow enough to block the passage, and the gap between cylinder 210 and piston 220 is wide enough to allow piston 220 to resonate without contact. The biasing element 240 optionally includes an elastic element, such as a spring. The biasing element 240 is connected between the movable piston and the immovable portion 250 of the pump body. Optionally, the piston moves sequentially between a flow-allowing state 220o and a flow-restricting state 220i, in which the piston does not obstruct flow through cylinder 210, and in the flow-restricting state 220i, the piston restricts flow through cylinder 210. In some embodiments, the piston moves in response to changes in fluid pressure. Alternatively or additionally, the movement is driven by resonant oscillation and / or an active force.

[0079] In some implementations, the flow direction of the pump can be switched by changing the phase relationship between the actuator and valve movement and / or the pressure phase in the pump chamber and the valve movement. This switching can be achieved by a slight change in the frequency of the actuator (e.g., diaphragm), which results in each valve lagging or leading the diaphragm in phase and / or a change in the flow direction.

[0080] Now refer to Figure 6 , Figure 6A one-way valve is shown, illustrated by a portion of a valve chamber wall 310 with an opening 320. A valve disc 330 can be displaced (vibrated) in a direction 350 parallel to the portion of wall 310. This disc has an opening 340 that is biased to its normal position relative to the opening 320. In other words, in the normal position, the valve is closed. When the pressure in the chamber increases, the disc 330 displaces upward and coincides with the opening 340. This upward position of the disc 330 allows pressurized fluid (e.g., liquid or gas) contained within the valve chamber to be blown away.

[0081] For the purposes of this invention, the term "proximal end" 333 of the petal member refers to the portion of the petal member near the member retainer (not shown), while the term "distal portion" 335 of the petal member refers to the opposite portion provided with the opening. Specifically, the proximal portion and the distal portion are designated as 333 and 335, respectively.

[0082] In some implementations, the flap 330 can be tuned. For example, when the valve is used in a device with a characteristic stroke frequency, the flap 330 can be tuned to resonate at the characteristic frequency.

[0083] Now refer to Figure 7 , Figure 7 A two-way valve is shown. According to this embodiment of the invention, the valve chamber wall 310 is provided with two openings 323 and 325, which are fluidly connected to pipes 327 and 329, respectively.

[0084] In response to pressure changes within the valve chamber, the vibrating valve disc 330 alternately blocks the top opening 325. In this position, air contained within the valve chamber is discharged through the lower opening 323 and the conduit 327. When the air pressure within the valve chamber is low, the aforementioned opening 323 is blocked. Simultaneously, outside air enters the valve chamber through the top opening 325 and the conduit 329.

[0085] In some implementations, the flap 330 can be tuned. For example, when the valve is used in a device with a characteristic stroke frequency, the flap 330 can be tuned to resonate at the characteristic frequency.

[0086] It should be emphasized that, according to the present invention, the lobes are narrow, so that fluids (e.g., liquids or gases in a chamber) can flow freely around the lobes as needed.

[0087] It should be emphasized that in the claimed miniature pump, there is no mechanical contact between the oscillating discs 40 and 60 and the non-movable parts 45 and 65, respectively. The proposed solution prevents the oscillating discs 40 and 60 from wearing as seen in known standard disc valves. Furthermore, during operation, mechanical contact between the valve discs and the valve seat results in significant losses, specifically generating substantial heat and noise. In the claimed miniature pump, energy loss is minimized.

[0088] According to one embodiment of the present invention, a resonant membrane micropump 100 for providing fluid pressure is disclosed. The pump 100 includes: (a) a pump chamber 20; (b) a resonantly driven membrane 30 configured to modulate the pressure of a fluid contained in the pump chamber 20; (c) an inlet check valve 110 adapted to allow fluid to flow into the chamber 20; and (d) an outlet check valve 120 adapted to allow fluid to flow out of the chamber 20. Each valve includes a channel 42 / 62 adapted to guide the fluid flow and a blocking element adapted to intermittently block the fluid flow.

[0089] In some embodiments, the blocking elements of valves 110 and 120 have a geometry and mass distribution such that when excited by membrane 30, the blocking elements of valves 110 and 120 are matched with resonant coherent oscillations in channels 42 and 62, respectively, such that the blocking elements block fluid flow in an antiphase manner.

[0090] According to another embodiment of the invention, the diaphragm 30 and the lobes 40 and 60 are configured to resonate outside the audible frequency range.

[0091] According to another embodiment of the invention, the blocking element is a resonant oscillating lobe 40 / 60.

[0092] According to another embodiment of the invention, the lobes 40 / 60 are configured to partially block the channels 42 / 62, and the gap 47 / 67 between the fixing member 45 / 65 and the lobes 40 / 60 is narrow enough to block the channels 42 / 62 and allow fluid outflow. The gap 47 / 67 provides sufficient space for non-contact resonant oscillation of the lobes 40 / 60.

[0093] According to another embodiment of the invention, the lobes have a tapered shape.

[0094] According to another embodiment of the invention, the blocking element is a resonant oscillating piston 220 connected to the abutment 250 by a spring 240.

[0095] According to another embodiment of the present invention, a method for providing fluid pressure is disclosed. The method includes the following steps: (a) providing a resonant membrane micropump 100 for providing fluid pressure. The pump 100 includes: (i) a pump chamber 20; (ii) a harmonically driven membrane 30 configured to modulate the pressure of a fluid contained in the pump chamber 20; (iii) an inlet check valve 110 adapted to allow the fluid to flow into the chamber 20; and (iv) an outlet check valve 120 adapted to allow the fluid to flow out of the chamber 20. Each valve includes a channel 42 / 62 adapted to guide the fluid flow and a blocking element adapted to intermittently block the fluid flow. The blocking elements of valves 110 and 120 have a geometry and mass distribution such that when excited by the membrane 30, the blocking elements are matched with resonant coherent oscillations in the channels 42 and 62, respectively, such that the blocking elements block the fluid flow in an out-of-phase manner.

[0096] In some embodiments, the step of blocking fluid flow is performed by resonant oscillation blocking elements 40 and 60 located in channels 42 and 62, respectively, when the membrane 30 is excited.

[0097] According to another embodiment of the invention, the membrane 30 and the lobes 40 and 60 resonate and oscillate at frequencies other than audible frequencies.

[0098] According to another embodiment of the invention, the step of blocking the channels 42 / 62 is performed by resonant oscillating lobes 40 and 60.

[0099] According to another embodiment of the invention, the channel 42 / 62 is partially blocked by the lobes 40 / 60, such that the gap 47 / 67 between the fixing member 45 / 65 and the lobes 40 / 60 is narrow enough to block the channel 42 / 62 and allow fluid to flow out. The gap 47 / 67 provides sufficient space for non-contact resonant oscillation of the lobes 40 / 60.

[0100] According to another embodiment of the invention, the step of blocking the channel 42 / 62 is performed by the lobes 40 / 60 having a tapered shape.

[0101] According to another embodiment of the invention, the step of blocking the channel 42 / 62 is performed by a resonant oscillating piston 220 connected to the abutment 250 via a spring 240.

[0102] In some embodiments, the valve of the present invention is formed using microtechnology, such as integrated circuits and / or electronic chips. For example, the valve can be fabricated by photolithography, deposition (e.g., chemical vapor deposition), and / or etching. The main process steps may optionally be supplemented by doping and etching, ion beam milling, etc.

[0103] Figure 8 This is a block diagram of a valve according to an embodiment of the present invention. In some embodiments, the valve includes an opening 882 and a flap 884. For example, the flap 884 may have a closed position and / or an open position, in which the flap 884 blocks (and / or partially blocks) flow through the opening, and in the open position, fluid is allowed to flow relatively freely through the opening. Optionally, the flap oscillates between the open and closed positions due to changes in fluid pressure and / or under the actuation of an active mechanism. Optionally, the flap 882 has a resonant frequency. For example, the resonant frequency can be adjusted to correspond to the drive frequency of the flow.

[0104] Figure 9 This is a flowchart of a method for controlling fluid flow according to an embodiment of the present invention. In some embodiments, the flow is driven at a characteristic frequency 992. Optionally, the valve oscillates between an open state and a closed state (e.g., fully closed and / or partially closed). Optionally, the valve is tuned such that the oscillation between the open and closed states has a resonant frequency that matches the characteristic driving frequency. For example, the valve may resonate at the characteristic driving frequency 992 994.

Claims

1. A fluid pumping device for pumping fluid between a fluid inlet and a fluid outlet, the fluid pumping device comprising: The room includes an entrance and an exit; At least one flow limiting element is disposed at a portion of the flow line and is configured to resonate along a continuous state between a first final state and a second final state, thereby affecting the distribution of fluid flow rate via the inlet or the outlet, wherein, in one or more first state ranges, the flow rate via the inlet or the outlet is less than the flow rate via the inlet or the outlet in one or more second state ranges. A driver configured to modulate the conditions in the chamber or on the at least one flow limiting element with a characteristic frequency distribution, thereby causing the at least one flow limiting element to resonate in a matched manner between the first final state and the second final state with approximately the characteristic frequency distribution. Wherein, the at least one flow-limiting element is a petal or leaf-like member, the petal or leaf-like member being fixed at one side of the petal or leaf-like member and having an opposite free side, the edge of the free side being close to the wall portion of the flow pipeline, and the distance between the edge and the wall portion changing at resonance, thereby defining whether the flow-limiting element is in the first state range or the second state range, wherein the free side is configured for contactless harmonic oscillation.

2. The fluid pumping device according to claim 1, wherein, The at least one flow restricting element is disposed at the inlet, or the at least one flow restricting element is disposed at a flow line section that affects the distribution of fluid flow through the inlet.

3. The fluid pumping device according to claim 1 or 2, wherein the fluid pumping device comprises two flow restricting elements, the two flow restricting elements being an inlet flow restricting element and an outlet flow restricting element, the inlet flow restricting element being disposed at the inlet or at a flow line portion that affects the distribution of fluid flow through the inlet, and the outlet flow restricting element being disposed at the outlet or at a flow line portion that affects the distribution of fluid flow through the outlet.

4. The fluid pumping device according to claim 3, wherein, The inlet flow restrictor and the outlet flow restrictor are configured to switch in opposite phases between the first state range and the second state range.

5. The fluid pumping device according to claim 1, wherein the fluid pumping device includes a single first state range with respect to a first state and a single second state range with respect to a second state, wherein, The first state range is defined between the first final state and the transition state, and the second state range is defined between the transition state and the second final state.

6. The fluid pumping device according to claim 1, wherein, The driver is configured to modulate the volume or pressure of the chamber with the characteristic frequency distribution.

7. The fluid pumping device according to claim 5, wherein, The driver includes a piezoelectric element configured to receive a voltage distribution at the characteristic frequency distribution.

8. The fluid pumping device according to claim 1, wherein, The flow pipeline section has a varying longitudinal cross-sectional profile, and the at least one flow restricting element spans at least a portion of the longitudinal cross-sectional profile and is deformable to define one or more first state ranges and one or more second state ranges.

9. The fluid pumping device according to claim 1, wherein, The at least one flow-limiting element oscillates harmonicly between deformable states that define one or more first state ranges and one or more second state ranges.

10. The fluid pumping device according to claim 1, wherein, The first state range is defined by limiting the flow rate of the fluid by at least 30% relative to the second state range.

11. A method for generating fluid pressure, the method comprising: The conditions in a chamber with a fluid inlet and a fluid outlet are modulated using a characteristic frequency distribution; The fluid flow rate via at least one of the fluid inlet and the fluid outlet is controlled by at least one flow limiting element, and the modulation causes the at least one flow limiting element to continuously resonate between a first final state and a second final state, wherein, in one or more first state ranges, the flow rate via the fluid inlet or the fluid outlet is less than the flow rate via the fluid inlet or the fluid outlet in one or more second state ranges. The continuous resonant oscillation of the at least one flow-limiting element is non-contact.

12. The method according to claim 11, wherein, The fluid flow rate through the fluid inlet is controlled by an inlet flow restriction element, and the fluid flow rate through the fluid outlet is controlled by an outlet flow restriction element.

13. The method according to claim 11, wherein, The inlet flow restrictor and the outlet flow restrictor are configured to switch in opposite phases between the first state range and the second state range.

14. The method according to claim 11, wherein, The modulation includes modulating the volume of the chamber.

15. The method according to claim 11, wherein, The at least one flow-limiting element oscillates harmonicly between deformable states that define one or more first state ranges and one or more second state ranges.

16. The method according to claim 11, wherein, The first state range restricts the fluid flow rate by at least 30% relative to the second state range.

17. A fluid pumping device for pumping fluid in a flow path between a fluid inlet and a fluid outlet, the fluid pumping device comprising: Two flow restriction / control elements are in flow communication with a fluid chamber arranged along the flow path, such that the fluid chamber is downstream of the first flow restriction / control element and upstream of the second flow restriction / control element. A driver for cyclically modulating the volume or pressure in the fluid chamber at a driver frequency; Each of the two flow limiting / control elements is configured to: in response to cyclic modulation of the volume or pressure, continuously and cyclically change its state between one or more first flow limiting state ranges and one or more second flow allowing state ranges, wherein the cyclical change of the state of the first flow limiting / control element is inverse to the cyclical change of the state of the second flow limiting / control element. Each of the two flow limiting / control elements has a resonant frequency, and the resonant frequencies of the two flow limiting / control elements are the same. Each of the two flow restriction / control elements is capable of reciprocating at a resonant frequency; Wherein, the driver frequency is set to approximately the resonant frequency; and The two flow limiting / control elements are lobes or leaf-shaped elements, which are fixed at one side of the lobes or leaf-shaped elements and have opposite free sides, with the edges of the free sides close to the wall portion of the flow pipeline. During resonance, the distance between the edges and the wall portion changes, thereby defining whether the flow limiting / control elements are in the first flow limiting state range or the second flow allowing state range. The free sides are configured for non-contact harmonic oscillation.

18. The fluid pumping apparatus according to claim 17, wherein, The driver includes a piezoelectric element configured to receive a voltage distribution at the driver frequency.

19. The fluid pumping apparatus according to claim 17, wherein, The first flow restriction state range is defined by limiting the flow rate of the fluid by at least 30% relative to the second flow allowable state range.

20. The fluid pumping apparatus according to claim 17, wherein, At least one of the flow restriction / control elements oscillates harmonicly between deformation states that define one or more first flow restriction state ranges and one or more second flow allowable state ranges.

21. A valve disposed at a portion of a flow line for controlling the flow distribution through said flow line portion, said valve comprising: At least one flow limiting element, the at least one flow limiting element being configured to continuously switch between one or more first state ranges and one or more second state ranges, wherein, in the one or more first state ranges, the flow rate via an inlet or outlet is less than the flow rate via an inlet or outlet in the one or more second state ranges; Wherein, the at least one flow-limiting element is a petal or leaf-like member, the petal or leaf-like member being fixed at one side of the petal or leaf-like member and having an opposite free side, the edge of the free side being close to the wall portion of the flow pipeline, and the distance between the edge and the wall portion changing at resonance, thereby defining whether the flow-limiting element is in the first state range or the second state range, wherein the free side is configured for contactless harmonic oscillation.

22. The valve according to claim 21, wherein, The at least one flow-limiting element is configured to resonate along a continuous state between a first final state and a second final state, defining one or more first state ranges and one or more second state ranges between the first final state and the second final state.

23. The valve of claim 22, wherein the valve comprises a single first state range with respect to a first state and a single second state range with respect to a second state, wherein, The first state range is defined between the first final state and the transition state, and the second state range is defined between the transition state and the second final state.

24. The valve according to claim 21, wherein, The flow pipeline section has a varying longitudinal cross-sectional profile, and the at least one flow restricting element spans at least a portion of the longitudinal cross-sectional profile and is deformable to define one or more first state ranges and one or more second state ranges.

25. The valve according to claim 21, wherein, The at least one flow-limiting element oscillates harmonicly between deformable states that define one or more first state ranges and one or more second state ranges.

26. The valve according to claim 21, wherein, The first state range is defined by limiting the fluid flow rate by at least 30% relative to the second state range.

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