Tunable ripple and dimple membrane for local heat transfer

Abstract

Aspects of the disclosure are directed to tunable heat transfer. In accordance with one aspect, the disclosure includes providing a sensed signal to a controller for monitoring heat transfer in a heat sink; applying a control voltage based on the sensed signal using a control law to modulate an actuator; and generating a turbulent fluid flow from a controlled fluid flow using the actuator which is modulated.

Description

TECHNICAL FIELD

[0001] This disclosure relates generally to the field of heat transfer, and, in particular, to a local heat transfer system using a tunable ripple and dimple membrane.BACKGROUND

[0002] A liquid cooling system may include heat sinks for thermal management. Some liquid cooling systems employ fixed turbulent trips to enhance heat transfer capability. However, turbulent flow may induce a high pressure drop which negatively impacts the overall efficiency of the thermal system design. Thus, a thermal design with tunable turbulent trips and without negative impacts is desired.SUMMARY

[0003] The following presents a simplified summary of one or more aspects of the present disclosure, in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0004] In one aspect, the disclosure provides tunable heat transfer. Accordingly, the present disclosure discloses an apparatus including: an actuator; a sensor coupled to the actuator, the sensor configured to provide a sensed signal for monitoring heat transfer in a heat sink; and a controller coupled to the sensor, the controller configured to apply a control voltage based on the sensed signal using a control law to modulate the actuator, wherein after the actuator is modulated, the actuator is configured to generate a turbulent fluid flow from a controlled fluid flow.

[0005] In one example, the sensor is further configured to update the sensed signal with an updated state information of the turbulent fluid flow and a heat flow rate. In one example, the controller is further configured to refine the control voltage based on the turbulent fluid flow, the heat flow rate and the updated sensed signal to generate a refined control voltage. In one example, the actuator is further configured to adjust the turbulent fluid flow based on the refined control voltage. In one example, the apparatus further includes a heat sink coupled to the actuator, the heat sink configured to ingest the controlled fluid flow into an inlet of the heat sink.

[0006] Another aspect of the disclosure provides an apparatus including: means for providing a sensed signal to a controller for monitoring heat transfer in a heat sink; means for applying a control voltage based on the sensed signal using a control law to modulate an actuator; and means for generating a turbulent fluid flow from a controlled fluid flow using the actuator which is modulated.

[0007] In one example, the apparatus further includes means for refining the control voltage based on the turbulent fluid flow, a heat flow rate and an updated sensed signal to generate a refined control voltage; and means for adjusting the turbulent fluid flow based on the refined control voltage. In one example, the means for generating the turbulent fluid flow is an actuator with a piezoelectric embedded membrane. In one example, the actuator includes a high coefficient of temperature (CTE) metal. In one example, the apparatus further includes a preset thermal-mechanical actuation structure configured to enable the high coefficient of temperature (CTE) metal based on a specified trigger temperature.

[0008] Another aspect of the disclosure provides a method including: providing a sensed signal to a controller for monitoring heat transfer in a heat sink; applying a control voltage based on the sensed signal using a control law to modulate an actuator; and generating a turbulent fluid flow from a controlled fluid flow using the actuator which is modulated.

[0009] In one example, the sensed signal is a temperature or wherein the sensed signal is proportional to a heat flow rate. In one example, the sensed signal is a filtered version of a raw sensor signal. In one example, the actuator includes a magnetic material and a magnetic source. In one example, the actuator includes an embedded membrane. In one example, the embedded membrane includes piezoelectric material.

[0010] In one example, the method further includes refining the control voltage based on the turbulent fluid flow, a heat flow rate and an updated sensed signal to generate a refined control voltage. In one example, the method further includes converting the controlled fluid flow into the turbulent fluid flow by mechanically perturbing the controlled fluid flow. In one example, the method further includes adjusting the turbulent fluid flow based on the refined control voltage. In one example, the method further includes ingesting the controlled fluid flow into an inlet of the heat sink.

[0011] These and other aspects of the present disclosure will become more fully understood upon a review of the detailed description, which follows. Other aspects, features, and implementations of the present disclosure will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary implementations of the present invention in conjunction with the accompanying figures. While features of the present invention may be discussed relative to certain implementations and figures below, all implementations of the present invention can include one or more of the advantageous features discussed herein. In other words, while one or more implementations may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various implementations of the invention discussed herein. In similar fashion, while exemplary implementations may be discussed below as device, system, or method implementations it should be understood that such exemplary implementations can be implemented in various devices, systems, and methods.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 illustrates a first example turbulent heat transfer system.

[0013] FIG. 2 illustrates a second example turbulent heat transfer system.

[0014] FIG. 3 illustrates a third example turbulent heat transfer system.

[0015] FIG. 4 illustrates a fourth example tunable heat transfer system.

[0016] FIG. 5 illustrates a fifth example tunable heat transfer system.

[0017] FIG. 6 illustrates a sixth example tunable heat transfer system.

[0018] FIG. 7 illustrates a seventh example tunable heat transfer system.

[0019] FIG. 8 illustrates a first example manufacturing process for a tunable heat transfer system.

[0020] FIG. 9 illustrates a second example manufacturing process for a tunable heat transfer system.

[0021] FIG. 10 illustrates various example cold plate designs for a tunable heat transfer system.

[0022] FIG. 11 illustrates an example flow diagram for implementing tunable heat transfer.DETAILED DESCRIPTION

[0023] The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0024] While for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more aspects, occur in different orders and / or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with one or more aspects.

[0025] Automotive systems and computing platforms may be constrained by their thermal environment. Various means of thermal management may be used to maintain an acceptable operational temperature range for electronic components in an automotive system. Conduction, convection and radiation are three different heat transfer techniques which may be employed for thermal management. Fluid flow using mass transport is one form of convection. Fluid flow may be used to transport heat from one location to another. Fluid flow is of two forms: laminar (e.g., smooth) and turbulent (e.g., chaotic).

[0026] A liquid cooling system may include a heat sink for transporting thermal energy from a heat source at one location to allow thermal dissipation in another location. The heat sink may incorporate a turbulent trip which induces turbulent flow for heat transfer. However, in some examples, the turbulent flow may introduce a larger than desired pressure gradient (e.g., a pressure drop) which may require a larger heat pump with higher pump pressure and high flow rate to overcome turbulent flow restrictions. In addition, the turbulent flow is intrinsically an unstable fluid flow with unpredictable flow dynamics. Consequently, the turbulent flow may require a more capable heat pump and a high flow velocity which increases system cost and design complexity.

[0027] For example, turbulent flow may result in improved heat transfer relative to laminar flow since turbulent boundary layers have more thermal layer intermixing. Greater intermixing may result in a more uniform velocity and temperature profile. Thus, from a heat transfer perspective, turbulent flow may be preferred. However, turbulent flow may increase system cost due to the need for a more capable equipment.

[0028] In one example, a tunable dimple at a thermal interface may induce turbulent flow by transitioning a laminar boundary layer into a turbulent boundary layer at a low flow velocity. That is, a tunable dimple may introduce a pressure gradient as required. A plurality of tunable dimples and ripples along a localized thermal interface may inhibit a maximum mass flow rate and may create a turbulent flow to increase heat transfer efficiency. For example, the plurality of tunable dimples and ripples may maintain the maximum mass flow rate while creating a tunable turbulent trip to actuate at a desired temperature or signal. This actuation mechanism may result in a more predictable and streamlined fluid flow until higher heat transfer is needed. As such, the plurality of tunable dimples and ripples allows an adaptive control strategy for introduction of turbulent flow.

[0029] FIG. 1 illustrates a first example turbulent heat transfer system 100. The turbulent heat transfer system 100 includes a mechanical structure to induce turbulence. The turbulent heat transfer system 100 also includes a cold plate or heat exchanger 110 with a local warm area 115 coupled to a chip (e.g., heat source) via a thermal interface and a plurality of turbulent trips (e.g., pin fins and dimples) 130 which transfers thermal energy to a second plate 120. In one example, a controlled fluid flow 140 traverses the plurality of turbulent trips 130 to generate a turbulent fluid flow 150. For example, the turbulent fluid flow 150 introduces a large pressure gradient to achieve a high heat transfer capability. For example, the mechanical structure to induce turbulence is the plurality of turbulent trips 130.

[0030] FIG. 2 illustrates a second example turbulent heat transfer system 200. The turbulent heat transfer system 200 includes a tunable mechanical structure to induce a variable turbulence condition. The turbulent heat transfer system 200 includes a cold plate or heat exchanger 210 with a local warm area 215 coupled to a chip (e.g., heat source) via a thermal interface and a non-actuated embedded membrane 230 which transfers thermal energy to a second plate 220. In one example, a controlled fluid flow 240 traverses across the cold plate or heat exchanger 210 to maintain a steady fluid flow 250. In one example, the cold plate or heat exchanger 210 includes a liquid filled heat sink. For example, the tunable mechanical structure to induce a variable turbulence condition is the non-actuated embedded membrane 230.

[0031] FIG. 3 illustrates a third example turbulent heat transfer system 300. The turbulent heat transfer system 300 includes a tunable mechanical structure to induce a variable turbulence condition. The turbulent heat transfer system 300 includes a cold plate or heat exchanger 310 with a local warm area 315 coupled to a chip (e.g., heat source) via a thermal interface and an actuated embedded membrane 330 which transfers thermal energy via fluid flow between the cold plate or heat exchanger 310 and a second plate 320. In one example, a controlled fluid flow 340 traverses the actuated embedded membrane 330 to generate a turbulent fluid flow 350. In one example, the turbulent fluid flow 350 introduces a negligible pressure gradient while achieving a high heat transfer capability. In one example, the actuated embedded membrane 330 implements a turbulent trip to increase heat transfer efficiency from the local warm area 315 with negligible pressure gradient. In one example, the cold plate or heat exchanger 310 includes a liquid filled heat sink. For example, the tunable mechanical structure to induce a variable turbulence condition is the actuated embedded membrane 330.

[0032] FIG. 4 illustrates a fourth example tunable heat transfer system 400. In one example, the tunable heat transfer system 400 includes a liquid cooled heat sink 410 (e.g., cold plate) with an inlet 411 and an outlet 412 for fluid flow. In one example, the liquid cooled heat sink 410 is coupled to an integrated circuit (IC) component 413 via a thermal interface to a hotspot 414, which is an embedded heat source. In one example, the thermal interface is a material called TIM (Thermal Interface Material) and the heat generated in the chip moves from the chip to the cold plate or heat exchanger. In one example, the IC component 413 is mounted onto a main printed circuit board (PCB) 415. In one example, a fluid enters the inlet 411 and transports heat from the hotspot 414 to the outlet 412. One skilled in the art would understand that within the scope and spirit of the present disclosure, the location of the IC component 413 may be in different locations with respect to liquid cooled heat sink 410 (e.g., cold plate), for example, top, bottom or side.

[0033] In one example, the liquid cooled heat sink 410 includes first plate 421 and a second plate 422 with an embedded dimple membrane 423 (i.e., an actuator) adjacent to a local hotspot 414. In one example, the liquid cooled heat sink 410 includes a controlled fluid flow 425 which traverses the embedded dimple membrane 423 to generate turbulence in the fluid flow 426. In one example, the embedded dimple membrane 423 is coupled to an actuator voltage 427. For example, the actuator voltage 427 may be controlled to actuate the embedded dimple membrane 423 via an actuation mechanism. For example, the actuation mechanism uses the actuator voltage 427 to induce mechanical motion in the embedded dimple membrane 423.

[0034] In one example, the actuation mechanism may be piezoelectricity. For example, piezoelectricity is a physical phenomenon where an actuator voltage change induces a mechanical force change. As shown in FIG. 4, an applied actuator voltage 427 shrinks the embedded dimple membrane 423 and conforms it to a dimple geometry. For example, the applied actuator voltage 427 may be operated statically or dynamically. In one example, active feedback control may be implemented using the integrated circuit component 413 based on system inputs, such as workload or temperature. For example, system inputs may be used to control the applied actuator voltage 427.

[0035] In one example, the actuation mechanism uses an electrically-induced movement of a piezoelectric material to actuate the embedded dimple membrane 423. For example, the piezoelectric material may be lead zirconate titanate (PZT) or a silicon thin-film material. In one example, the actuator voltage depends on piezoelectric multilayers with a voltage range of 5 to 130 volts to allow for maximum tunability. In one example, approximate size of the piezoelectric material may be fitted to a width of a cold plate dimension (e.g., channel length) and can be any geometric shape spanning a reference dimension (e.g., 40 mm). In one example, the piezoelectric material may be embedded in the embedded dimple membrane 423 or it may be separate.

[0036] In one example, when the embedded dimple membrane 423 is not actuated, it forms an outer surface of a membrane cavity structure 441. For example, the membrane cavity structure 441 within the second plate 422 includes a dimple geometry fitting 443 and a membrane adhesion point 445. For example, the applied actuator voltage 427 is at zero volts of electric potential when the embedded dimple membrane 423 is not actuated.

[0037] In one example, control software in a processor may be the source of the actuation mechanism. In one example, the control software may execute a control law to determine control directives. In one example, the control software may use a sensed signal to determine a fluid flow state. In one example, the sensed signal may be used to derive control directives in accordance with the control law. In one example, control software may send control directives which are translated into actuator voltage settings. In one example, the actuator voltage settings may be static or dynamic.

[0038] In one example, the actuator voltage settings create dimples by shrinking the embedded dimple membrane 423 over the dimple geometry fitting 443. In one example, the actuation mechanism may be operated statically such that a desired actuator voltage setting, ripples and dimples are triggered. In one example, the actuation mechanism may be operated dynamically, for example, in a cyclical manner such that the embedded dimple membrane 423 is rapidly actuated on and off for ripple tuning. For example, ripple tuning creates ripples on a flowing fluid and a physical barrier which impacts the fluid flow.

[0039] FIG. 5 illustrates a fifth example tunable heat transfer system 500. In one example, the tunable heat transfer system 500 includes a plate 512 with a magnetic membrane 514. In one example, when the magnetic membrane 514 is not actuated, it forms an outer surface of a membrane cavity structure 511. For example, the membrane cavity structure 511 within the plate 512 includes a dimple geometry fitting 543 and a membrane adhesion point 515. For example, an applied actuator voltage 517 is at a zero voltage setting when the magnetic membrane 514 is not actuated. For example, the applied actuator voltage 517 is applied to a magnetic coil 516 for generation of a null magnetic field (not shown). For example, an actuation mechanism uses the applied actuator voltage 517 to induce mechanical motion in the magnetic membrane 514.

[0040] FIG. 5 also illustrates the tunable heat transfer system 500 when the magnetic membrane 514 is actuated on the plate 512. In one example, the applied actuator voltage 517 is at a nonzero voltage setting and is applied to the magnetic coil 516 for generation of the magnetic field 525. In one example, the magnetic field 525 provides a magnetic force to pull down the magnetic membrane 514 to conform to the dimple geometry fitting 543.

[0041] In one example, the magnetic membrane 514 is actuated via the magnetic field 525 which is generated by the magnetic coil 525 (e.g., an electromagnet) or by a permanent magnet. In one example, the actuation may be controlled by a control software in a processor. In one example, the control software may execute a control law to determine control directives. In one example, the control software may use a sensed signal to determine a fluid flow state. In one example, the sensed signal may be used to derive control directives in accordance with the control law. In one example, control software may send control directives which are translated into applied actuator voltage settings. For example, the applied actuator voltage settings may be operated statically or dynamically.

[0042] In one example, the magnetic membrane 514 may be composed of a composite material such as magnetic nanoparticles embedded in an elastic membrane or fabric. In one example, the magnetic membrane 514 may be composed of magnetic-responsive polymer composite materials such as ferromagnetic material (e.g., iron cobalt, FeCo) or diamagnetic materials such as pyrolytic graphite. In one example, the magnetic membrane 514 may have a linear dimension commensurate with the plate 512 (e.g., width of plate channel) and may be any geometric shape which spans the width of the plate channel.

[0043] In one example, the applied actuator voltage 517 may have a range of 0 to 50 volts and the resultant magnetic field may be as high as 1 Tesla to conform the magnetic membrane 514 to the shape of the dimple geometry fitting 513.

[0044] FIG. 6 illustrates a sixth example tunable heat transfer system 600. In one example, the tunable heat transfer system 600 includes a plate 612 with a micro magnetic membrane 614. In one example, when the micro magnetic membrane 614 is not actuated, it forms an outer surface of a membrane cavity structure. For example, the membrane cavity structure within the plate 612 includes a dimple geometry fitting 643. In one example, the micro magnetic membrane 614 includes embedded discrete micro magnets or ferromagnetic particles.

[0045] In one example, upon activation (i.e., with application of a nonzero voltage at an applied actuator voltage 627), a magnetic field 625 generated by a magnetic coil 626 provides the actuation of the micro magnetic membrane 614 to conform to the dimple geometry fitting 643. In one example, the actuation may be controlled by a control software in a processor. In one example, the control software may execute a control law to determine control directives. In one example, the control software may use a sensed signal to determine a fluid flow state. In one example, the sensed signal may be used to derive control directives in accordance with the control law. In one example, control software may send control directives which are translated into applied actuator voltage settings to the magnetic coil 626.

[0046] In one example, an alternative version of the tunable heat transfer system 600 includes an elastic membrane 634 coupled to a magnetic ring / frame 638 with a plurality of adhesion points 639. In one example, each adhesion point of the plurality of adhesion points 639 is centered over a dimple of the dimple geometry fitting 633. In one example, the magnetic ring / frame 638 is coupled to a plate 632. In one example, with application of a nonzero voltage at an applied actuator voltage 647, a magnetic field 645 generated by a magnetic coil 646 pulls the magnetic ring / frame 638 and the elastic membrane 634 to form dimples.

[0047] FIG. 7 illustrates a seventh example tunable heat transfer system 700. In one example, the tunable heat transfer system 700 includes a first plate 711 and a second plate 712 with an embedded ripple geometry 713 and an elastic membrane 716. In one example, the second plate 712 also includes a local hotspot 714 and a high CTE metal 717. In one example, the high CTE metal is a metal with a high coefficient of thermal expansion (CTE). For example, CTE quantify a relative volumetric expansion or contraction per degrees Celsius (e.g., units of parts per million (ppm) per deg C). In one example, the high CTE metal 717 may include a plurality of fixed points 718 for attachment to the second plate 712.

[0048] In one example, actuation of the embedded ripple geometry 713 and the elastic membrane 716 may be enabled using a preset thermal-mechanical actuation which depends on a specified trigger temperature to trigger the high CTE metal 717 to move the embedded ripple geometry 713 above the surface of the second plate 712. In one example, the embedded ripple geometry 713 includes a hard mechanical stop after moving the embedded ripple geometry 713. In one example, the plurality of fixed points 718 may be used to retract the embedded ripple geometry 713 when the temperature exceeds a maximum temperature limit.

[0049] Alternatively, the actuation may be controlled by a control software in a processor. In one example, the control software may execute a control law to determine control directives. In one example, the control software may use a sensed signal to determine a fluid flow state. In one example, the sensed signal may be used to derive control directives in accordance with the control law. In one example, control software may send control directives which are translated into control inputs which impose thermal-mechanical actuation.

[0050] In one example, the elastic membrane 716 may include any thin film membrane, polymer cloth, polymer film, or any other elastic material with a smooth and high slip surface. For example, the clastic membrane 716 may be fitted to a width of a channel of the second plate 712 with any geometric shape which spans the channel width.

[0051] In one example, the high CTE metal 717 may be an alloy such as Nitinol (i.e., nickel titanium alloy) in a plate shape or a mesh shape. For example, Nitinol may be a shape memory alloy (SMA), i.e. an alloy which restores its shape. In one example, the high CTE metal 717 may be an expanding paraffin wax which increases in volume upon melting.

[0052] In one example, the embedded ripple geometry 713 may have a plurality of ripples and dimples with an arbitrary combination of material constituents. In one example, the embedded ripple geometry 713 may be placed on any side of the channel and a plurality of local hotspots may be serviced by the second plate 712. In one example, the embedded ripple geometry 713 and elastic membrane 716 induce a turbulent fluid flow 729 from a controlled fluid flow 715.

[0053] FIG. 8 illustrates a first example manufacturing process 800 for a tunable heat transfer system. In one example, a first manufacturing step 810 defines a location for an embedded ripple geometry within a cold plate base 812 and coupled to a channel 813 and a channel cover 811. In one example, a second manufacturing step 820 machines a cavity 823 (e.g., hole) in the cold plate base 812 during casting. In one example, a third manufacturing step 830 mounts the embedded ripple geometry 833 inside the cavity 823 in the cold plate 812. For example, the mounting maintains a flat surface and creates a hermetic seal. In one example, a fourth manufacturing step 840 actuates the embedded ripple geometry 833 as a functional test of the tunable heat transfer system 800. In one example, the first manufacturing process builds the cold plate base 812 around the embedded ripple geometry 833 prior to brazing the channel cover 811.

[0054] FIG. 9 illustrates a second example manufacturing process 900 for a tunable heat transfer system. In one example, a first manufacturing step 910 defines a location for an embedded ripple geometry within a cold plate base 912 and coupled to a channel 913 and a channel cover 911. In one example, a second manufacturing step 920 opens a cavity 923 in the cold plate base 912 and drills holes for screws and an O-ring. In one example, a third manufacturing step 930 mounts the embedded ripple geometry 933 inside the cavity 923 in the cold plate base 912. In one example, a fourth manufacturing step 940 actuates the embedded ripple geometry 933 as a functional test of the tunable heat transfer system 900. In one example, the second manufacturing process may retrofit the cold plate base 912 by bolting down from the backside of the cold plate base 912 with the O-ring. For example, the embedded ripple geometry 933 may be mounted on any wall of the cold plate base 912 to tune for the desired thermal performance.

[0055] FIG. 10 illustrates various example cold plate designs 1000 for a tunable heat transfer system. In a first design 1010, a serpentine cold plate with smaller channel dimensions (e.g., a channel width of 2 to 10 mm) is shown. In a second design 1020, a single channel cold plat with larger channel dimensions (e.g., a channel width of 20 to 50 mm) is shown. In a third design 1030, a plenum type cold plate. In one example, the third design 1030 includes an inlet plenum with perpendicular piping to a plenum for heat transport to a cold-side plenum and an outlet plenum. In a fourth design 1040, a cold plate cross-section is shown with an integrated circuit (IC) mounted on a main PCB. For example, the cold plate is used for cooling. For example, an embedded ripple geometry may be located near a local hotspot.

[0056] FIG. 11 illustrates an example flow diagram 1100 for implementing tunable heat transfer. In block 1110, ingest a controlled fluid flow into an inlet of a heat sink. In one example, a controlled fluid flow is ingested into an inlet of a heat sink. In one example, the heat sink transports heat from a localized heat source, for example, an integrated circuit (IC) component. In one example, the controlled fluid flow is a laminar fluid flow. In one example, the fluid flow is a cooled liquid flow. In one example, the heat sink is surrounded by cold plate. In one example, the step of block 1110 is performed by a heat sink, thermal fins, etc.

[0057] In block 1120, provide a sensed signal to a controller for monitoring heat transfer in the heat sink. In one example, a sensed signal is provided to a controller for monitoring heat transfer in the heat sink. In one example, the sensed signal is a temperature. In one example, the sensed signal is a smoothed or filtered version of a raw sensor signal. In one example, the sensed signal is proportional to a heat flow rate. In one example, the step of block 1120 is performed by a sensor, a thermometer, a thermal sensor, a flow meter, etc. In one example, the sensed signal may be a temperature measurement of an IC component. In one example, the sensed signal may be a workload measurement of the IC component. In one example, the sensed signal may be an external temperature (e.g., heat sink temperature or actuator temperature) correlated to the IC component.

[0058] In block 1130, apply a control voltage based on the sensed signal using a control law to modulate an actuator. In one example, a control voltage based on the sensed signal using a control law is applied to modulate an actuator. In one example, the actuator includes an embedded membrane. In one example, the actuator (e.g., the embedded membrane) includes piezoelectric material. In one example, the piezoelectric material is mechanically actuated by the control voltage. In one example, the piezoelectric material is lead ziconate titanate (PZT) or a silicon thin film material. In one example, the actuator includes a magnetic material and a magnetic source. In one example, the magnetic source is an electromagnet controlled by the control voltage. In one example, the magnetic material is magnetic nanoparticles embedded in an elastic membrane or fabric. In one example, the magnetic material is composed of magnetic-responsive polymer composite materials such as ferromagnetic material (e.g., iron cobalt, FeCo) or diamagnetic materials (e.g., pyrolytic graphite). In one example, the actuator is modulated to increase the heat transfer rate by introducing turbulence in the heat sink.

[0059] In one example, the actuator includes a high coefficient of temperature (CTE) metal or alloy. In one example, the high CTE metal or alloy is enabled using a preset thermal-mechanical actuation structure which depends on a specified trigger temperature. In one example, the control law is a proportional control law. In one example, the control law is a proportional plus derivative control law. In one example, the control law is a proportional plus derivative plus integral control law. In one example, the step of block 1130 is performed by a controller, a processor, a microcontroller, a microprocessor, a system on a chip (SOC), a microcomputer, etc. In one example, the control law may be a bilevel (e.g., on / off) control law where actuation depends on a sensed signal (e.g., temperature) threshold. In one example, the control law may be cyclic with an arbitrary duty cycle (e.g., 1 sec on, 0.5 sec off).

[0060] In block 1140, generate a turbulent fluid flow from the controlled fluid flow using the actuator which is modulated (“modulated actuator”). In one example, after the actuator is modulated, generate a turbulent fluid flow from the controlled fluid flow using the actuator which is modulated. In one example, the modulated actuator converts the controlled fluid flow into the turbulent fluid flow by mechanically perturbing the controlled fluid flow. In one example, the modulated actuator operates statically. In one example, the modulated actuator operates cyclically. In one example, the modulated actuator operates dynamically. In one example, the step of block 1140 is performed by an actuator, a piezoelectric structure, a magnetic structure, a high coefficient of temperature (CTE) metal, a high coefficient of temperature (CTE) alloy, etc.

[0061] In block 1150, refine the control voltage based on the turbulent fluid flow, a heat flow rate and an updated sensed signal to generate a refined control voltage. In one example, the turbulent fluid flow may be indirectly measured and calculated or may be inferred based on specific and measurable system conditions (e.g., flow measurements). In one example, the heat flow rate may be correlated or calculated based on other sensors coupled to the IC component. In one example, the control voltage is refined based on the turbulent fluid flow, a heat flow rate and an updated sensed signal to generate a refined control voltage. In one example, the updated sensed signal represents updated state information of the turbulent flow and heat flow rate. In one example, the step of block 1150 is performed by a controller, a processor, a microcontroller, a microprocessor, a system on a chip (SOC), a microcomputer, etc.

[0062] In block 1160, adjust the turbulent fluid flow based on the refined control voltage. In one example, adjusting the turbulent fluid flow may be achieved by changing system conditions (e.g., flow measurements). In one example, the turbulent fluid flow may be adjusted on feedback monitored by the updated sensed signal. In one example, the turbulent fluid flow is adjusted based on the refined control voltage. In one example, the step of block 1160 is performed by an actuator, a piezoelectric structure, a magnetic structure, a high coefficient of temperature (CTE) metal, a high coefficient of temperature (CTE) alloy, etc. In one example, the piezoelectric structure and magnetic structure may be actuated by the refined control voltage. In one example, the high CTE metal may be actuated by a thermal controller (e.g., thermo-electric cooler) to heat and cool the high CTE metal.

[0063] In one aspect, one or more of the steps for providing tunable heat transfer in FIG. 11 may be executed by one or more processors which may include hardware, software, firmware, etc. The one or more processors, for example, may be used to execute software or firmware needed to perform the steps in the flow diagram of FIG. 11. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0064] The software may reside on a computer-readable medium. The computer-readable medium may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip), an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD)), a smart card, a flash memory device (e.g., a card, a stick, or a key drive), a random access memory (RAM), a read only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and / or instructions that may be accessed and read by a computer. The computer-readable medium may also include, by way of example, a carrier wave, a transmission line, and any other suitable medium for transmitting software and / or instructions that may be accessed and read by a computer. The computer-readable medium may reside in a processing system, external to the processing system, or distributed across multiple entities including the processing system. The computer-readable medium may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging materials. The computer-readable medium may include software or firmware. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

[0065] Any circuitry included in the processor(s) is merely provided as an example, and other means for carrying out the described functions may be included within various aspects of the present disclosure, including but not limited to the instructions stored in the computer-readable medium, or any other suitable apparatus or means described herein, and utilizing, for example, the processes and / or algorithms described herein in relation to the example flow diagram.

[0066] Within the present disclosure, the word “exemplary” is used to mean “serving as an example, instance, or illustration.” Any implementation or aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term “aspects” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation. The term “coupled” is used herein to refer to the direct or indirect coupling between two objects. For example, if object A physically touches object B, and object B touches object C, then objects A and C may still be considered coupled to one another-even if they do not directly physically touch each other. The terms “circuit” and “circuitry” are used broadly, and intended to include both hardware implementations of electrical devices and conductors that, when connected and configured, enable the performance of the functions described in the present disclosure, without limitation as to the type of electronic circuits, as well as software implementations of information and instructions that, when executed by a processor, enable the performance of the functions described in the present disclosure.

[0067] One or more of the components, steps, features and / or functions illustrated in the figures may be rearranged and / or combined into a single component, step, feature or function or embodied in several components, steps, or functions. Additional elements, components, steps, and / or functions may also be added without departing from novel features disclosed herein. The apparatus, devices, and / or components illustrated in the figures may be configured to perform one or more of the methods, features, or steps described herein. The novel algorithms described herein may also be efficiently implemented in software and / or embedded in hardware.

[0068] It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.

[0069] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”

[0070] One skilled in the art would understand that various features of different embodiments may be combined or modified and still be within the spirit and scope of the present disclosure.

Claims

1. An apparatus comprising:an actuator;a sensor coupled to the actuator, the sensor configured to provide a sensed signal for monitoring heat transfer in a heat sink; anda controller coupled to the sensor, the controller configured to apply a control voltage based on the sensed signal using a control law to modulate the actuator,wherein after the actuator is modulated, the actuator is configured to generate a turbulent fluid flow from a controlled fluid flow.

2. The apparatus of claim 1, wherein the sensor is further configured to update the sensed signal with an updated state information of the turbulent fluid flow and a heat flow rate.

3. The apparatus of claim 2, wherein the controller is further configured to refine the control voltage based on the turbulent fluid flow, the heat flow rate and the updated sensed signal to generate a refined control voltage.

4. The apparatus of claim 3, wherein the actuator is further configured to adjust the turbulent fluid flow based on the refined control voltage.

5. The apparatus of claim 4, further comprising a heat sink coupled to the actuator, the heat sink configured to ingest the controlled fluid flow into an inlet of the heat sink.

6. An apparatus comprising:means for providing a sensed signal to a controller for monitoring heat transfer in a heat sink;means for applying a control voltage based on the sensed signal using a control law to modulate an actuator; andmeans for generating a turbulent fluid flow from a controlled fluid flow using the actuator which is modulated.

7. The apparatus of claim 6 further comprising:means for refining the control voltage based on the turbulent fluid flow, a heat flow rate and an updated sensed signal to generate a refined control voltage; andmeans for adjusting the turbulent fluid flow based on the refined control voltage.

8. The apparatus of claim 7, wherein the means for generating the turbulent fluid flow is an actuator with a piezoelectric embedded membrane.

9. The apparatus of claim 8, wherein the actuator includes a high coefficient of temperature (CTE) metal.

10. The apparatus of claim 9, further comprising a preset thermal-mechanical actuation structure configured to enable the high coefficient of temperature (CTE) metal based on a specified trigger temperature.

11. A method comprising:providing a sensed signal to a controller for monitoring heat transfer in a heat sink;applying a control voltage based on the sensed signal using a control law to modulate an actuator; andgenerating a turbulent fluid flow from a controlled fluid flow using the actuator which is modulated.

12. The method of claim 11, wherein the sensed signal is a temperature or wherein the sensed signal is proportional to a heat flow rate.

13. The method of claim 11, wherein the sensed signal is a filtered version of a raw sensor signal.

14. The method of claim 11, wherein the actuator includes a magnetic material and a magnetic source.

15. The method of claim 11, wherein the actuator includes an embedded membrane.

16. The method of claim 15, wherein the embedded membrane includes piezoelectric material.

17. The method of claim 15, further comprising refining the control voltage based on the turbulent fluid flow, a heat flow rate and an updated sensed signal to generate a refined control voltage.

18. The method of claim 17, further comprising converting the controlled fluid flow into the turbulent fluid flow by mechanically perturbing the controlled fluid flow.

19. The method of claim 17, further comprising adjusting the turbulent fluid flow based on the refined control voltage.

20. The method of claim 19, further comprising ingesting the controlled fluid flow into an inlet of the heat sink.

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