Thermal management device and system

Abstract

To provide a thermal management device and system.SOLUTION: The thermal management system comprises: a thermoelectric component; a two phase heat transfer unit; and a controller. The heat transfer unit has a phase transition chamber and microfeatures in the phase transition chamber that induce a capillary force in the working fluid that drives the working fluid through the phase transition chamber. The controller is configured to operate the thermoelectric component and the heat transfer unit such that the heat transfer unit cools one side of the thermoelectric component to a first temperature and the thermoelectric component changes the temperature of the target material on the other side to a second temperature of + / - 60°C. of the first temperature within 0.5 to 20 seconds.SELECTED DRAWING: Figure 1C

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the priority and benefits of U.S. Provisional Application No. 62 / 877,122, filed Jul. 22, 2090, and U.S. Provisional Application No. 62 / 954,759, filed Dec. 30, 2019, both of which are incorporated herein by reference in their entirety.

[0002] This technology relates to devices, heat sources, or another type of substrate for cooling and heating target materials such as tissues.

Background Art

[0003] Many electronic devices, medical and aesthetic devices, and high - heat - flux systems use thermal management devices to operate within an acceptable temperature range and / or achieve a desired outcome. In many applications, the thermal management system extracts and dissipates heat flux and maintains the temperature within an acceptable range for the target material.

[0004] One type of thermal management system is a two - phase heat transfer device in which a working fluid transitions from a liquid phase to a gas phase and extracts heat from the target material. In such two - phase heat transfer devices, a high heat transfer rate can be achieved due to the latent heat of vaporization of the working fluid. Two - phase heat transfer devices are disclosed for use in cooling semiconductor devices (e.g., controllers, memory devices, etc.), computer systems (e.g., servers), tissues, hair, lipids, and medical devices used in pain management treatments, as well as wearable cooling devices.

[0005] Controllers, memory devices, and semiconductor devices such as light-emitting diodes often need to dissipate heat in order to maintain an acceptable operating temperature. As the speed and capacity of these devices increase, the heat flux increases and more heat is required to be dissipated to maintain the acceptable operating temperature. However, in many applications, the heat flux of high-performance semiconductor devices and computing systems is too high for the heat transfer system, resulting in the speed and capacity of the system being limited. This problem is only exacerbated by the fact that mobile phones, tablets, and laptop computers have a smaller size and / or higher performance. Similarly, large-scale server applications where many servers are stored in a common location (e.g., data storage devices, web systems, and computing centers) have significant heat dissipation requirements. Two-phase heat transfer systems have high heat transfer rates, but they are often too large and cumbersome to be used in combination with semiconductor devices and high-performance computing systems.

[0006] Some medical and aesthetic procedures heat and / or cool tissue to reduce pain, manage swelling, reduce adipose tissue for body contouring, remove hair, tighten the skin (e.g., remove wrinkles), remove lesions, modify sebaceous glands, and for other thermal therapies. The tissue can be heated using high-frequency energy, laser energy, ultrasonic energy, X-ray radiation beams, and other energy modalities. For example, thermotherapy uses heat to damage cancer cells (see, e.g., U.S. Patent No. 9,802,063) to treat cancer. Other medical applications such as cryogenic tissue remodeling treat symptoms by cooling the tissue (see, e.g., U.S. Patent No. 10,363,080).

[0007] One challenge in heating and / or cooling tissue is accurately controlling the temperature of the target tissue, as different types of tissue react differently to heating and cooling, and different depths within the tissue can react differently because blood flow can significantly affect the temperature of the target site. Another challenge is unwanted heating and cooling of adjacent tissue, such as nerve or epidermal tissue. Two-phase heat transfer systems are used for thermal management of target tissue in medical and aesthetic applications, but conventional systems often have slow response times and thus do not provide precise thermal modulation of the target tissue. In addition, many medical and aesthetic applications use bulky heat transfer devices that are uncomfortable for patients and impractical for treating at-home or certain body parts (e.g., face, knee, shoulder, ankle, wrist, etc.).

[0008] Devices for cooling a target material or substrate are known. See, for example, U.S. Patent No. 10,217,692. Methods for cooling the skin in conjunction with skin treatment are also known. See Nelson JS, Majaron B, Kelly KM., Active Skin Cooling in Conjunction with Laser Dermatologic Surgery, Semin Cutan Med Surg. 2000;19:253-66 and Das et al., J. Cutan. Aesthet. Surg.2016;9(4):215-219. SUMMARY OF THE INVENTION MEANS FOR SOLVING THE PROBLEM

[0009] DETAILED DESCRIPTION OF THE EMBODIMENTS Aspects of the present technology are directed to systems for regulating the temperature of mammalian tissue (e.g., human tissue) and target materials such as electronic devices (e.g., substrates). It should be understood that the devices according to the present technology can control the temperature of the surface of the substrate and / or adjust the temperature at a certain depth within the substrate. According to one aspect, a system for regulating the temperature of a substrate includes a heat transfer unit operably connected to a thermoelectric component for heating or cooling the substrate surface.

[0010] The present technology can be used in the treatment of mammalian tissue (used synonymously with human tissue throughout), computer chips, semiconductor devices, integrated circuit devices, laser systems (e.g., high-power laser systems with high heat fluxes that need to be dissipated to generate a desired output beam and / or power), the outer skin of supersonic flying objects, parabolic solar collectors, high-performance computing systems, radio frequency (RF) systems, solar power generation or concentrating solar power generation systems, new supersonic passenger aircraft applications, turbine blades, or any other surface or volume heat dissipation device or system, etc., in high heat flux applications. The thermal management system of the present technology is particularly effective for cooling a patient's skin during treatment using a laser beam or a needle. For example, when tissue is treated with a laser beam or a needle, the epidermis and dermis are cooled, reducing pain. It should be understood that various embodiments of the devices of the present technology can be applied and / or utilized in a wide range of applications according to desires, needs, or requirements. The present invention provides, for example, the following. (Item 1) A thermal management system, A thermoelectric component having a first side configured to be thermally coupled to a target material and a second side opposite the first side. A two-phase heat transfer unit thermally coupled to a second side of the thermoelectric component, the two-phase heat transfer unit comprising: 1) a phase change chamber having an inlet region and an outlet region; 2) micro-features within the phase change chamber, the micro-features within the phase change chamber being spaced apart from each other such that the micro-features induce a capillary force in the working fluid to drive the working fluid from the inlet region of the phase change chamber to the outlet of the phase change chamber; 3) an inlet through which the working fluid flows into the two-phase heat transfer unit in a liquid phase; and 4) an outlet through which at least a portion of the working fluid flows out of the two-phase heat transfer unit in a gas phase. A controller configured to operate the thermoelectric component and the two-phase heat transfer unit such that the two-phase heat transfer unit cools the second side of the thermoelectric component to a first temperature and the thermoelectric component changes the temperature of the target material to a second temperature within 0.5 to 20 seconds, the second temperature being + / −60° C. of the first temperature. A system comprising the above. (Item 2) The system according to item 1, wherein the contact member, the thermoelectric component, and the two-phase heat transfer unit all have a height measured along the direction of heat flow from the contact member through the thermoelectric component of 2 mm to 25 mm. (Item 3) The system according to item 2, wherein the controller is configured to set the two-phase heat transfer unit to a first temperature of 5° C. to −20° C. on a second side of the thermoelectric unit, and the controller is configured to operate the thermoelectric unit to heat the contact member to a second temperature of 20° C. to 40° C. within 1 to 10 seconds. (Item 4) The system according to item 2, wherein the two-phase heat transfer unit has a thickness measured from the thermoelectric component in the direction of heat flow of 3 mm to 8 mm. (Item 5) The micro features are separated from each other by 10 microns to 1,000 microns, for the system according to item 2. (Item 6) The micro features are channels defined by walls extending from an inlet region to an outlet region of the phase transition chamber, for the system according to item 5. (Item 7) The micro features are pins within the phase transition chamber, for the system according to item 5. (Item 8) The micro features are separated from each other by 10 microns to 250 microns, for the system according to item 2. (Item 9) The thermoelectric component includes a first Peltier module. The system further includes a second Peltier module positioned laterally to the first Peltier module. The phase transition chamber of the two-phase heat transfer unit includes a first phase transition chamber. The two-phase heat transfer unit further includes a second phase transition chamber positioned laterally to the first phase transition chamber. The first phase transition chamber is aligned with the first Peltier module, and the second phase transition chamber is aligned with the second Peltier module. The system according to item 1. (Item 10) The controller is configured to set the two-phase heat transfer unit to a first temperature of 5°C to -20°C on a second side of the thermoelectric unit. The controller is configured to operate the thermoelectric unit to heat the contact member to a second temperature of 10°C to 40°C within 1 to 10 seconds, for the system according to item 9. (Item 11) The two-phase heat transfer unit has a thickness measured from the thermoelectric component in the direction of the heat flow of 2 mm to 8 mm, for the system according to item 10. (Item 12) The micro features are separated from each other by 10 microns to 1,000 microns, for the system according to item 10. (Item 13) The system according to item 12, wherein the micro feature is a channel defined by a wall extending from an inlet region to an outlet region of the phase transition chamber. (Item 14) The system according to item 12, wherein the micro feature is a pin within the phase transition chamber. (Item 15) The system according to item 10, wherein the micro features are spaced from each other by 10 microns to 250 microns. (Item 16) The system according to item 1, wherein the thermoelectric component has a first volumetric heat capacity, and the two-phase heat transfer unit has a second volumetric heat capacity that does not exceed one of 50%, 100%, 150%, 200%, 250%, 300%, 400%, or 500% of the first volumetric heat capacity. (Item 17) The system according to item 1, further comprising a condenser fluidly coupled to an inlet and an outlet of the two-phase heat transfer unit, wherein the working fluid is contained within the condenser and the two-phase heat transfer unit. (Item 18) The system according to item 1, further comprising a non-invasive monitoring system having a source for transmitting energy to the target material and a detector for detecting a component of the energy transmitted to the target material by the source, wherein the temperature gradient within the target material is determined by information from the detector. (Item 19) The system according to item 18, wherein the source is a light source and the detector is a photodetector. (Item 20) A method for thermally managing a target material, comprising: Positioning a first side of a thermoelectric component to be thermally coupled to the target material; Using a two-phase heat transfer unit thermally coupled to a second side of the thermoelectric component to cool the second side of the thermoelectric component to a first temperature; Adjusting an electric current through the thermoelectric component such that the target material reaches a second temperature within 0.5 to 20 seconds, wherein the second temperature is + / - 60 °C of the first temperature. A method comprising (Item 21) The method according to item 20, wherein both the thermoelectric component and the two-phase heat transfer unit have a height measured along the direction of heat flow through the thermoelectric component of 2 mm to 25 mm. (Item 22) The method according to item 21, wherein the first temperature is 5 °C to -20 °C on the second side of the thermoelectric unit, the second temperature is 20 °C to 40 °C, and the time from the first temperature to the second temperature is 1 to 10 seconds. (Item 23) The method according to item 22, wherein the two-phase heat transfer unit has a thickness measured from the thermoelectric component in the direction of heat flow of 2 mm to 8 mm. (Item 24) The method according to item 22, wherein the micro-features are spaced 10 microns to 1,000 microns from each other. (Item 25) The method according to item 24, wherein the micro-features are channels defined by walls extending from an inlet region to an outlet region of the phase transition chamber. (Item 26) The method according to item 24, wherein the micro-features are pins within the phase transition chamber. (Item 27) A device for treating human tissue, comprising A tissue heating module configured to heat a target tissue to a therapeutic temperature, and A thermal management system, wherein the thermal management system comprises (a) A contact plate having high thermal conductivity, and (b) A thermoelectric component having a first side configured to be thermally coupled to the contact plate and a second side opposite the first side. (c) A two-phase heat transfer unit thermally coupled to the second side of the thermoelectric component, the two-phase heat transfer unit comprising: 1) a phase change chamber having an inlet region and an outlet region; 2) micro-features within the phase change chamber, the micro-features within the phase change chamber being spaced apart from each other such that the micro-features induce capillary forces in the working fluid to drive the working fluid from the inlet region of the phase change chamber to the outlet of the phase change chamber; 3) an inlet through which the working fluid flows into the two-phase heat transfer unit in the liquid phase; and 4) an outlet through which at least a portion of the working fluid flows out of the two-phase heat transfer unit in the gas phase. (d) A controller configured to operate the thermoelectric component and the two-phase heat transfer unit such that the two-phase heat transfer unit cools the second side of the thermoelectric component to a first temperature and the thermoelectric component changes the temperature of the contact plate to a second temperature within 0.5 to 20 seconds, the second temperature being + / - 60 °C of the first temperature. A thermal management system comprising: A device comprising: (Item 28) The device according to item 27, wherein the tissue heating module comprises a laser configured to heat the target tissue to the therapy temperature, while the contact plate cools adjacent tissue. (Item 29) The device according to item 27, further comprising a non-invasive monitoring system having a source for transmitting energy to the target material and a detector for detecting components of the energy transmitted to the target material by the source, wherein the temperature gradient within the target material is determined from information from the detector. (Item 30) The system according to item 29, wherein the source is a light source and the detector is a light detector. (Item 31) A device for cooling a person's tissue, A contact plate having high thermal conductivity, and A thermoelectric component, wherein the thermoelectric component has a first side configured to be thermally coupled to the contact plate and a second side opposite to the first side. A two-phase heat transfer unit thermally coupled to the second side of the thermoelectric component, the two-phase heat transfer unit comprising: 1) a phase change chamber having an inlet region and an outlet region; 2) micro-features within the phase change chamber, the micro-features within the phase change chamber being spaced apart from each other such that the micro-features induce a capillary force on the working fluid to drive the working fluid from the inlet region of the phase change chamber to the outlet of the phase change chamber; 3) an inlet through which the working fluid flows into the two-phase heat transfer unit in a liquid phase; and 4) an outlet through which at least a portion of the working fluid flows out of the two-phase heat transfer unit in a gas phase. A controller configured to operate the thermoelectric component and the two-phase heat transfer unit such that the two-phase heat transfer unit cools the second side of the thermoelectric component to a first temperature and the thermoelectric component changes the temperature of the contact plate to a second temperature within 0.5 to 20 seconds, the second temperature being + / −60° C. of the first temperature. A device comprising the above. (Item 32) The device according to item 31, further comprising a non-invasive monitoring system having a source for transmitting energy to the target material and a detector for detecting a component of the energy transmitted to the target material by the source, wherein the temperature gradient within the target material is determined by information from the detector. (Item 33) The system according to item 32, wherein the source is a light source and the detector is a photodetector. (Item 34) A semiconductor device, A semiconductor component having an integrated circuit network, A thermal management system, wherein the thermal management system is (a) a thermoelectric component having a first side configured to be thermally coupled to the semiconductor component and a second side opposite the first side; (b) a two-phase heat transfer unit thermally coupled to the second side of the thermoelectric component, the two-phase heat transfer unit comprising: 1) a phase change chamber having an inlet region and an outlet region; 2) micro features within the phase change chamber, the micro features within the phase change chamber being spaced apart from each other such that the micro features induce a capillary force in the working fluid to drive the working fluid from the inlet region of the phase change chamber to the outlet of the phase change chamber; 3) an inlet through which the working fluid flows into the two-phase heat transfer unit in a liquid phase; and 4) an outlet through which at least a portion of the working fluid flows out of the two-phase heat transfer unit in a gas phase; (c) a controller configured to operate the thermoelectric component and the two-phase heat transfer unit such that the two-phase heat transfer unit cools the second side of the thermoelectric component to a first temperature and the thermoelectric component changes the temperature of the semiconductor component to a second temperature; A thermal management system comprising A semiconductor device comprising (Item 35) The semiconductor device according to item 34, wherein the semiconductor component is a controller. (Item 36) The semiconductor device according to item 34, wherein the semiconductor component is a memory device. (Item 37) The semiconductor device according to item 34, wherein the semiconductor component is within a server. (Item 38) A method for modifying the temperature of a patient's tissue, comprising (a) At a first temperature T1, thermally contacting a device having a thermoelectric component with an outer surface of a first tissue target, wherein a heat transfer unit is in thermal contact with the thermoelectric component; (b) Activating a current through the thermoelectric component in a first direction to cause cooling of the outer surface of the first tissue target from the first temperature T1 to about 8°C to about -15°C within about 2 to 4 seconds, wherein the heat transfer unit removes a heat flux generated by the thermoelectric component and maintains the thermoelectric component at an operating temperature below at least 50°C; (c) Activating a current through the thermoelectric component in a second direction opposite to the first direction to cause heating of the outer surface of the first tissue target from about 8°C to about -15°C to at least about 20°C within about 1 to 3 seconds; A method comprising the above steps. (Item 39) The method according to item 38, wherein the first tissue target is irradiated with a laser beam or punctured with a needle after act (b) and before act (c). (Item 40) The method according to item 38, wherein the first tissue target is irradiated with a laser beam while the device remains in contact with the first tissue target after act (b) and before act (c). (Item 41) The method according to item 38, wherein the first tissue target is punctured with a needle while the device remains in contact with the first tissue target after act (b) and before act (c). (Item 42) The method according to item 38, wherein the heat transfer unit is a two-phase evaporative heat transfer device. (Item 43) The method according to item 38, wherein the heat transfer unit is a two-phase evaporative heat transfer device including an evaporation system having a plurality of walls extending downward from a base into a reservoir of an evaporative fluid. (Item 44) The heat transfer unit is a two-phase evaporative heat transfer device, and the two-phase evaporative heat transfer device has a condenser unit that is operably connected thereto, receives vapor from the two-phase evaporative heat transfer device, and condenses the vapor into an evaporative fluid, the method according to item 38. (Item 45) The heat transfer unit is a two-phase thermo-evaporative heat transfer device connected to an inflow and an outflow conduit for the passage of an evaporative fluid therethrough, the method according to item 38. (Item 46) In act (b), activating a current through the thermoelectric component in a first direction causes cooling of an outer surface of the first tissue target from the first temperature T1 to from about 8 °C to about -2 °C within about 3 seconds, the method according to item 38. (Item 47) In act (b), activating a current through the thermoelectric component in a first direction causes cooling of an outer surface of the first tissue target from the first temperature T1 to from about 4 °C to about -2 °C within about 2 to 4 seconds, the method according to item 38. (Item 48) In act (b), activating a current through the thermoelectric component in a first direction causes cooling of an outer surface of the first tissue target from the first temperature T1 to from about 4 °C to about -2 °C within about 3 seconds, the method according to item 38. (Item 49) In act (c), activating a current through the thermoelectric component in a second direction opposite to the first direction causes heating of an outer surface of the first tissue target from from about 8 °C to about -2 °C to at least about 20 °C within about 2 seconds, the method according to item 38. (Item 50) The device includes a transparent material, and laser light is transmitted through the transparent material to the surface of the first tissue target to treat the first tissue target, the method according to item 38. (Item 51) The method according to item 38, wherein the device includes one or more channels through the device, and through the one or more channels, laser light is transmitted to the surface of the first tissue target to treat the first tissue target. (Item 52) The method according to item 38, wherein the device includes one or more channels through the device, and through the one or more channels, one or more needles are carried to pierce the surface of the first tissue target to treat the first tissue target. (Item 53) The method according to item 38, wherein the device is attached to the hand-held laser emitting device in a manner of receiving laser light from the hand-held laser emitting device. (Item 54) The method according to item 38, further comprising thermally contacting the device with the outer surface of a second tissue target and repeating acts (a)-(c). (Item 55) The method according to item 38, further comprising continuously repeating acts (a)-(c) on a plurality of target tissues. (Item 56) The method according to item 38, wherein the device includes a plurality of thermoelectric components, and the plurality of thermoelectric components are electrically connected in series and thermally connected in parallel. (Item 57) The method according to item 38, wherein the device includes a plurality of thermoelectric components, the plurality of thermoelectric components are electrically connected in series and thermally connected in parallel, each thermoelectric component is positioned adjacent thereto, and has an associated microchannel evaporation structure for removing heat from the thermoelectric component. (Item 58) The method according to item 38, wherein the thermoelectric component is electrically connected to a programmable power source. (Item 59) The method according to item 38, wherein the device includes a plurality of thermoelectric components, the plurality of thermoelectric components are electrically connected in series and thermally connected in parallel, and the plurality of thermoelectric components are electrically connected to a programmable power source. Brief Description of the Drawings

[0011]

Figure 1A

Figure 1B

Figure 1C

[0012]

Figure 2

[0013]

Figure 3

[0014]

Figure 4

[0015]

Figure 5

[0016]

Figure 6

[0017]

Figure 7

[0018]

Figure 8A

Figure 8B

[0019]

Figure 9

[0020]

Figure 10

[0021]

Figure 11

[0022]

Figure 12

[0023]

Figure 13

[0024]

Figure 14

[0025]

Figure 15

[0026]

Figure 16A

Figure 16B

Figure 16C

Figure 16D

[0027]

Figure 17

[0028]

Figure 18A

Figure 18B

Figure 18C

Figure 18D

Figure 18E

[0029]

Figure 19

[0030]

Figure 20

[0031]

Figure 21A

Figure 21B

Figure 21C

[0032]

Figure 22

Figure 23

[0033]

Figure 24

[0034]

Figure 25

[0035]

Figure 26

[0036]

Figure 27

[0037]

Figure 28

[0038] The figures are to be understood as presenting illustrations of embodiments of the invention and / or examples of principles related thereto. As will be apparent to those of ordinary skill in the art having knowledge of the present technology, other devices, methods, and particularly, apparatuses used in heat transfer devices, temperature sensors, micro features, and / or thermoelectric components will have configurations and components that are, in part, determined by their specific use. Like reference numerals refer to corresponding parts throughout several views of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

[0039] FIGS. 1A - 1C are isometric views of a thermal management system 100 for cooling and / or heating a target material 101 according to an embodiment of the present technology. The thermal management system 100 can accurately and rapidly control the temperature at the surface of the target material 101 and / or at a certain depth within the target material 101. As described in further detail below, the target material 101 can be mammalian tissue (e.g., human skin, adipose tissue, hair, lesions, cancerous cells, etc.), semiconductor devices (e.g., controllers, memory devices, light-emitting diodes, servers, high-performance computers, etc.), and other applications involving high heat fluxes (e.g., lasers).

[0040] Referring to both FIGS. 1A and 1B, a thermal management system 100 can include an optional contact member 110, at least one thermoelectric component (TEC) 120a (FIG. 1B) thermally coupled to the contact member 110, and a two-phase heat transfer unit 140 thermally coupled to the TEC 120a. FIG. 1A shows the fully assembled thermal management system 100, and FIG. 1B shows the thermal management system 100 without the heat transfer unit 140. The thermal management system 100 can have several TECs, for example, a first, a second, and a third TEC 120a-c (collectively referred to as TEC 120 throughout). The thermal management system 100 can have any number of TECs 120 and is not limited to having three TECs 120. The thermal management system 100 can also include a condenser 180 operably coupled to the heat transfer unit 140 to form a closed system, and a controller 190 operably coupled to the TEC 120, the heat transfer unit 140, and / or the condenser 180. During operation, the working fluid contained within the heat transfer unit 140 and the condenser 180 changes from a liquid phase to a gas phase within the heat transfer unit 140, cooling one side of the TEC 120, and the controller 190 regulates the current through the TEC 120 and / or the flow of the working fluid through the heat transfer unit 140 to manage the temperature of the contact member 110 and thus the target material 101.

[0041] In the assembled state shown in FIG. 1A, the contact member 110, the TEC 120, and the heat transfer unit 140 can all be held together by bolts 199. The TEC 120 can further be attached to the contact member 110 by a first thermal interface material and to the lower surface of the heat transfer unit 140 by a second thermal interface material. The thermal management system 100 can have any suitable length L and width W to cover a desired area of the target material 101. The thermal management system 100 can be thin, with a height H of 2 mm to 25 mm, including 5 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, and 25 mm. The heat transfer unit 140 itself can have a thickness T of 2 mm to 20 mm, including 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, and 19 mm. For example, when the heat transfer unit 140 is directly integrated into the second portion 122b of the TEC 120, the overall height H can be 2 to 3 mm. The height H and the thickness T can be measured in the direction of heat flow through the TEC 120 (arrow HF in FIG. 1B).

[0042] Each of the TECs 120 has a first portion 122a and a second portion 122b. The first and second portions 122a-b are understood with respect to the positioning of the first portion 122a being thermally bonded to the target material 101 and the second portion 122b being opposed to the first portion 122a with respect to the surface of the target material 101. The first portion 122a of the TEC 120 can include the first outer surface 124a of the TEC 120 (i.e., the lower surface in FIG. 1B) and a part of the TEC 120 that extends inwardly from the first outer surface 124a by a distance. The second portion 124b of the TEC 120 can include the second outer surface 124b of the TEC 120 (i.e., the upper surface in FIG. 1B) and a part of the TEC 120 that extends inwardly from the second outer surface 124b by a distance into the interior of the TEC 120. It should be understood that the TEC 120 may have an equidistant midpoint within the interior of the TEC 120 between the first and second outer surfaces 124a-b. The first and second portions 122a-b of the TEC 120 are electrically connected to a power source. For example, each of the TECs 120 may include a first electrical contact 126a (shown by an imaginary line) in the first portion 122a and a second electrical contact 126b in the second portion 122b, through which current can flow in either direction.

[0043] The first portion 122a of the TEC 120 is intended to be thermally coupled to the surface of the target material 101, either directly or indirectly. For example, the first portion 122a of the TEC 120 can be indirectly thermally coupled to the target material 101 via a contact member 110, which can be a plate, panel, film, or fabric made from a material with high thermal conductivity (e.g., an aluminum plate or panel). The thermal management system 100 can include two or more such plates or panels or films that are in contact with each other, as desired. The second portion 122b of the TEC 120 is thermally coupled to the heat transfer unit 140, either directly or indirectly. For example, the second portion 122b of the TEC 120 is directly coupled to the heat transfer unit 140 by a thermal interface material having high thermal conductivity. The heat transfer unit 140 can remove heat from the target material 101 as well as heat generated by the TEC 120.

[0044] Although not desiring to be bound by scientific theory, heat flow is induced within the TEC 120 in a direction by an electric current. According to one non-limiting aspect, when a device for adjusting the temperature of the target material 101 is activated and electricity flows in a direction from the second portion 122b of the TEC 120 to the first portion 122a of the TEC 120, the first portion 122a is cooled relative to its ambient or starting temperature, i.e., the temperature of the first portion 122a decreases, thereby removing heat from the target material 101. The second portion 122b is thus heated relative to its ambient or starting temperature or generates heat. It should be understood that embodiments are contemplated in which the direction of heat flow can be the same as or opposite to the direction of electric current flow.

[0045] The heat transfer unit 140 may be fixed to the second portion 122b of the TEC 120, or may be selectively removed from the second portion 122b of the TEC 120 using a piezoelectric driver, an electric motor, or other electromechanical device to break the thermal contact with the TEC 120. Similarly, the TEC 120 may also be selectively removed (i.e., separated) from the target material 101 and / or the contact member 110 using a piezoelectric driver, an electric motor, or other electromechanical driver to break the thermal contact therewith. Such a device may be known as a thermal switch as long as heat is used to shape the switch and create a physical separation (e.g., an air gap) between two surfaces such as the two-phase heat transfer unit 140 and the TEC 120 or the TEC 120 and the contact member 110. According to one aspect, it may be desirable to disconnect the heat transfer unit 140 from the TEC 120 or disconnect the TEC 120 from the contact member 110 over a given time period.

[0046] Referring to FIGS. 1A and 1B, the heat transfer unit 140 covers the second portion 122b of the TEC 120. The heat transfer unit 140 has an inlet 142, an outlet 144, and a cover 146. During operation, the working fluid flows from the condenser 180 to the inlet 142 in a liquid state or a mixed liquid-vapor state (e.g., a high-pressure single-stage closed cooling system), and at least a portion of the working fluid flows back from the outlet 144 to the condenser 180 in a vapor state. The cover 146 retains the working fluid within the heat transfer unit 140 and, together with other components, defines the flow characteristics of the working fluid through the heat transfer unit 140.

[0047] FIG. 1C illustrates an embodiment of the internal structure of the heat transfer unit 140 with the cover 146 (FIG. 1B) removed. The heat transfer unit 140 can include a base 148 to which the cover 146 is connected, at least one phase change chamber 150 (shown and identified individually as three phase change chambers 150a-c), an inlet 142, an outlet 144, and a duct system 160 fluidly coupled to the phase change chambers 150a-c. The phase change chambers 150a-c are at least generally aligned with corresponding ones of the TECs 120a-c. For example, the phase change chambers 150a-c can each be directly superimposed above the corresponding ones of the TECs 120a-c, respectively. The heat transfer unit 140 can have, as shown, a single inlet 142 and a single outlet 144 and can inspect all of the phase change chambers 150a-c, or the heat transfer unit 140 can have several inlets 142 and an outlet 144. For example, the heat transfer unit 140 can have one or more inlets 142 and / or outlets 144 for each of the phase change chambers 150a-c or for any other purpose to provide a desired flow of working fluid through the heat transfer unit 140.

[0048] The phase change chambers 150a-c include microfeatures 152, an inlet region 154, and an outlet region 156. The microfeatures 152 shown in FIG. 1C are pins or struts arranged in a grid type array, although in other embodiments the microfeatures can be elongated walls. The microfeatures 152 define microchannels 153 through which a working fluid flows through the phase change chambers 150a-c. The microfeatures 152 can have different arrangements other than being arranged in a straight uniform row, as described below with reference to FIGS. 18A, 18C, and 18D, whether the microfeatures 152 are pins or elongated walls. The microfeatures 152 can be spaced apart from each other by a uniform distance, or the distance between the microfeatures 152 can vary in relation to the position and flow characteristics of the inlet region 154 and the outlet region 156. For example, the microfeatures 152 can be spaced apart from each other by a first distance within the inlet region 154 and by a second distance within the outlet region 156. The second distance can be greater than the first distance and can accommodate the flow of vapor through the outlet region 156, or the second distance can be less than the first distance and can accommodate the capillary forces imparted to the liquid phase of the working fluid flowing through the phase change chambers 150a-c. Additionally, the spacing between the microfeatures 152 within one of the phase change chambers 150 can be the same as or different from the spacing between the microfeatures 152 within one or more of the other phase change chambers 150a-c.

[0049] The spacing between the micro-features 152 can be selected to (a) generate capillary forces in the working fluid that drive the working fluid from the inlet region 154 to the outlet region 156 of the phase change chamber, (b) accommodate the flow of vapor through the inlet and outlet regions 154 and 156 of the phase change chambers 150a-c, and / or (c) form a desired meniscus between adjacent micro-features 152 to improve the evaporation zone along each micro-feature 152 and improve heat transfer. In some embodiments, the spacing between the micro-features is selected such that the capillary forces induced in the working fluid allow the heat transfer unit 140 to operate in all directions (e.g., the heat transfer unit 140 is inverted such that it is below or at an angle relative to horizontal of the TEC). The spacing between the micro-features 152 can be in a range having, for example, a lower limit of 50 nm, 100 nm, 200 nm, 500 nm, 1 μm, 2 μm, 5 μm, or 10 μm and an upper limit of 25 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1,000 μm. In specific examples, the spacing between the micro-features can be 100 nm to 1,000 μm, 100 nm to 500 μm, 100 nm to 400 μm, 100 nm to 300 μm, 100 nm to 250 μm, 100 nm to 200 μm, 50 nm to 150 μm, 50 nm to 100 μm, 50 nm to 50 μm, 50 nm to 25 μm, or 50 nm to 10 μm.

[0050] The duct system 160 includes a primary duct 162 having a first channel 163a fluidly coupled to the inlet 140 and a second channel 163b extending from the first channel 163a along the phase change chambers 150a-c. The duct system 160 further includes manifold ducts 164a-c (collectively referred to as "manifold duct 164") and an exhaust duct 166. The manifold duct 164 is fluidly coupled to the second channel 163b of the primary duct 162 at the junction 165, and the exhaust duct 166 is fluidly coupled to the outlet 144. The phase change chambers 150a-c can further include an inlet port 167 and an outlet port 168. The inlet port fluidly couples the individual manifold ducts 164 to the inlet region 154 of the phase change chambers 150a-c, and the outlet port 168 fluidly couples the outlet region of the phase change chambers 150a-c to the exhaust duct 166. The inlet port 167 can be a small passage having a uniform arrangement along the individual manifold ducts 164a-c (shown only along the manifold duct 164a for convenience, but also present along the manifold ducts 164b and 164c). The outlet port 168 can be a larger passage at the end of the outlet region 156 of the phase change chambers 150a-c through which vapor passes into the exhaust duct 166. The outlet ports 168 can be arranged differently so that the different phase change chambers 150a-c provide a desired vapor flow along the exhaust duct 166. For example, in the illustrated embodiment, the outlet port 168 of the first phase change chamber 150a can be in the upstream portion of the exhaust duct 166 with respect to the first phase change chamber 150a, the outlet port 168 of the second phase change chamber 150b can be in the midstream portion of the exhaust duct 166 with respect to the second phase change chamber 150b, and the outlet port 168 of the third phase change chamber 150c can be in the downstream region of the exhaust duct 166 with respect to the third phase change chamber 150c.

[0051] During operation, the working fluid flows in the liquid phase from the condenser 180 (FIG. 1A) to the inlet 140, and then the working fluid flows to the inlet port 167 through the primary duct 162 and the manifold ducts 164a-c. The manifold ducts 164a-c and the junction 165 can be configured to provide a uniform distribution (e.g., uniform flow) of the working fluid to the inlet port 167 along the phase transition chambers 150a-c. The working fluid then flows through the inlet port 167, the microchannels 153 of the individual phase transition chambers 150a-c, and the outlet port 168 in flows F1, F2, and F3. As the working fluid flows through the phase transition chambers 150a-c, it transitions from the liquid phase to the gas phase within the evaporation region along the microfeatures 152.

[0052] The base 148 of the heat transfer unit 140 can be made of aluminum, copper, silicon, or other materials with high thermal conductivity. The phase transition chambers 150a-c, the microfeatures 152, and the duct system 160 can be formed by masking and etching the base as is known in semiconductor manufacturing, water jet cutting, laser ablation, or three-dimensional printing. Additionally, the surface of the base 148 within the phase transition chambers 150a-c can be textured, such as by sandblasting.

[0053] The heat transfer unit 140 removes heat from the second portion 122b of the TEC 120, whether generated by electricity flowing through the TEC 120 or from the target material 101 itself (e.g., when the target material is an active heat source such as a controller, memory device, laser, etc.). Since the TEC 120 can generate a high heat flux, the heat transfer unit 140 should remove (e.g., dissipate) at least a portion of the high heat flux. In this way, the TEC 120 can continuously cool the target material, i.e., continuously remove heat from the target material. The heat transfer unit 140 can prevent or otherwise limit the TEC 120 from overheating during use. If the heat transfer unit 140 is not used, the heat generated in the second portion 122b of the TEC 120 will gradually increase, thereby reducing the ability of the TEC 120 to cool the target material. The heat transfer unit 140 is selected to have the ability to remove sufficient heat generated in the second portion 122b of the TEC 120 and enable the first portion 122a of the TEC 120 to cool the target material as desired.

[0054] The TEC 120 may maintain the target material 101 at a constant temperature or may decrease and / or increase the temperature of the target material 101 according to a desired temperature profile. One or more auxiliary heating or cooling elements may be positioned adjacent to the target material 101 to provide auxiliary heating or cooling of the target material 101 in addition to the TEC 120. For example, the TEC 120 may be used to cool the target material surface, and a separate resistive heating element may be used to heat the target material surface. Additionally, the TEC 120 may be used to heat the target material surface, and an auxiliary cooling element may be used to cool the target material surface.

[0055] According to one aspect, the TEC 120 may be used to heat the target material 101 or otherwise increase its temperature. For example, when the thermal management system 100 is activated and electricity flows through the TEC 120, the first portion 122a of the TEC 120 is heated or generates heat, i.e., the temperature of the first portion 122a of the TEC increases, compared to its surroundings or starting temperature, while the second portion 122b of the TEC 120 is cooled compared to its surroundings or starting temperature. Thus, the temperature of the target material can be increased compared to its ambient temperature. It should be understood that embodiments of the semiconductor material or array of semiconductor materials of the TEC 120 can be configured such that the direction of heat flow can be the same as or opposite to the direction of current flow. When used in this mode of operation to heat the target material, the heat transfer unit 140 may be deactivated or physically separated from the TEC 120 so that the heat transfer unit 140 does not remove heat from the cold side of the TEC 120. However, the heat transfer unit 140 and the TEC 120 may alternatively operate in parallel, including reducing the temperature from the ambient or starting temperature and then increasing the temperature, to achieve the desired temperature profile of the target material even when the TEC 120 is warmer in the first portion 122a than in the second portion 122b.

[0056] The TEC 120 may decrease or increase the temperature of the target material according to a desired temperature profile depending on the direction of the flow of current through the TEC 120. According to one aspect of the present technology, the TEC uses a directional flow of electricity through the TEC and, in combination with the heat transfer unit 140, to remove heat from the TEC 120 when desired, the first portion 122a of the TEC 120, and thus may be used to decrease and / or increase the temperature of the target material. By changing the direction of the flow of electricity, the first portion 122a of the TEC 120 can be rapidly and precisely cooled or heated over a desired time period according to a desired temperature profile, thereby rapidly and precisely cooling or heating the target material 101.

[0057] When in the cooling mode, the heat transfer unit 140 removes the heat generated by the TEC 120 that would otherwise affect the ability of the TEC 120 to cool the target material in a desired manner. For example, using a first directional flow of electricity, the TEC 120, in combination with the heat transfer unit 140, may cool the target material 101 from an initial ambient temperature Temp1 (which can be the temperature of the patient's tissue, i.e., 35°C to 37°C) to a lower temperature Temp2 (which can be 9°C to -4°C or -10°C or -15°C or -20°C) over a time period time1 (which can be in the range of 0.1 to 5 seconds or 10 seconds or 20 seconds). Using a second directional flow of electricity that is opposite to the first directional flow of electricity, the TEC 120 may then heat the target material from Temp2 (which can be 9°C to -4°C or -10°C or -15°C or -20°C) to a higher temperature Temp3 (which can be room temperature or the normal temperature of the patient's tissue) over a time period time2 (which can be in the range of 0.1 to 5 seconds). These ranges are examples and do not limit the scope and usefulness of the embodiments described herein. For example, additional temperature ranges can be 15°C to -10°C, 10°C to -6°C, 10°C to 0°C, 15°C to -15°C, 10°C to -10°C, or the like. For example, the time ranges can be 0.05 to 20 seconds, 0.05 to 10 seconds, or 0.1 to 7 seconds, and the like.

[0058] The directional flow of electricity may be modified from one direction to another or vice versa to repeatedly cool or heat the target material, depending on the desired application or use. Since the heating and cooling of the TEC120 are driven by the direction of current flow, the temperature of the first portion 122a of the TEC120, and thus the temperature of the target material 101 thermally coupled to the TEC120, can be modified rapidly, i.e., in less than about 1 second to several seconds, and with high precision, i.e., about 0.1 °C to 0.5 °C, 1.0 °C, 1.5 °C, or 2.0 °C. The low thermal inertia of the heat transfer unit 140 (e.g., low heat capacity or low volumetric heat capacity) enables precise switching between the cooling mode and the heating mode within a range of 0.1 seconds to 5 seconds. The heat transfer unit 140 has a thin profile of 0.7 mm to 25 mm or 5 mm to 15 mm, but removes the high heat flux generated by the TEC120 and can cool the target material from its ambient temperature to a lower temperature, e.g., 9 °C to -4 °C or -10 °C or -15 °C or -20 °C, within a time period of 0.1 seconds to 5 seconds, such as 2 - 3 seconds. In some embodiments, the heat transfer unit 140 generally has a thickness T of 0.7 mm to 1.0 mm.

[0059] The TEC120s may be used together or operated independently to heat or cool a target material with a given surface area or volume. By using each TEC120 that generates heat within a given surface area, the heat transfer unit 140 can remove the heat generated from the group of TEC120s. Each TEC120 may have its own heat transfer unit 140, or a single integrated heat transfer unit 140 as shown in FIGS. 1A - 1C may remove heat from all or a subset of the TEC120s. For example, the heat transfer unit 140 may have a surface area that exceeds the combined surface area of a plurality of TEC120s. According to one aspect, the heat transfer unit 140 and the TEC120s are arranged relative to each other and the target material 101 such that light or radiant energy or a mechanical treatment device can operate through or between the heat transfer unit and the TECs, heating deeper tissue to a desired treatment temperature that would otherwise be painful or damage the epidermis, while allowing the surface of the target material (e.g., the epidermis) to be cooled.

[0060] The TEC120s can be attached to the flexible contact member 110, or a subset of one or more TECs can be attached to the rigid contact member 110, and the rigid contact members 110 are coupled together by hinges to flex between the rigid contact members 110. In such an embodiment, each TEC120 or subset of TEC120s can have an individual heat transfer unit 140 with one or more phase change chambers 150, and the individual heat transfer units 140 are thermally and physically separated (disconnected) from each other, and the heat management system can allow for flexing between the individual TEC120s or subsets of TEC120s. This configuration is particularly useful in applications where the target material 101 is non - planar, such as many body parts (e.g., shoulders, knees, ankles, face, torso, lower back, head, etc.).

[0061] The TEC120s may be arranged in an array of rows and columns or any desired pattern to achieve a desired objective. For example, a device as described herein may include from 2 to 200 TEC120s arranged within the surface area of a thermally conductive contact member (e.g., a plate or film or support). Depending on the number of TEC120s, the TEC120s may be arranged in a square pattern, rectangular pattern, circular pattern, or other pattern relative to the thermally conductive contact member according to the surface area and / or the contour of the target material 101. According to one aspect, the TEC120s may be positioned horizontally relative to each other in the same plane. According to one aspect, the TEC120s may be positioned perpendicular to each other, such as by overlapping and stacking the TEC120s.

[0062] Each TEC120 may be operated independently to achieve different heating or cooling at different locations of the target material 101, or all of the TEC120s may be operated simultaneously to achieve uniform heating or cooling of the target material 101. A subset of the TEC120s may be operated independently to achieve different heating or cooling at different locations on the target material 101. Additionally, each TEC120 or subset of TEC120s can have a separate heat transfer unit 140, and pairs of TEC120s and heat transfer units 140 can be operated independently or collectively.

[0063] A device for adjusting the temperature of a target material surface as described herein includes a heat transfer unit 140, and the TEC 120 is also operably connected to the device to sense or detect temperature, heat flux, or pressure at one or more locations along or within the device, and may include one or more temperature sensors, heat flux sensors, and / or pressure sensors (collectively, identified by reference numeral 170). Such temperature and pressure sensors may provide feedback regarding the operation of the device for adjusting the temperature of the target material surface, assist in adjusting the operation of the device, and provide a desired temperature or temperature profile of the target material. Thus, a device for adjusting the temperature of a target material surface as described herein non-invasively cools a target material, such as tissue, to a predetermined temperature. The target material has a certain thickness, and it should be understood that cooling or heating the target material using the device described herein can generate a temperature profile as a function of the depth of the target material. For example, the outer surface of the target material may have a lower temperature than the temperature of the treatment site within the target material. This results in a temperature profile of the target material. Once the desired temperature of the outer surface of the target material is achieved, or the desired temperature profile within the target material as a function of the depth of the target material is reached, the target material may then be processed or treated at a predetermined temperature or temperature profile. In some embodiments, the temperature profile is generated as a function of time, location on the target material, and / or depth within the target material.

[0064] The contact member 110 can be one or more thermally conductive plates or surfaces or films that thermally interconnect the heat transfer unit 140 to the TEC 120 and / or the TEC 120 to the target material 101. For the purposes of further discussion, a thermally conductive contact member, which can be a thermally conductive plate, surface, braid, fabric, or film, will be referred to. The heat transfer unit 140 may have its own thermally conductive contact member, and the TEC 120 may have its own thermally conductive contact member. The thermally conductive contact member of the heat transfer unit 140 may be attached to or otherwise mounted to the TEC 120. A single thermally conductive contact member may be between the heat transfer unit 140 and the TEC 120. The thermally conductive contact member may be positioned at the bottom of the TEC 120 or may be a part of the bottom of the TEC 120 to provide a thermal connection between the TEC 120 and the target material 101. The thermally conductive contact member may have a thickness of from 0.01 mm to 5 mm.

[0065] The thermally conductive contact member may have any suitable configuration, shape, design, thickness, etc. for contacting a given surface. The thermally conductive contact member may be rigid or flexible. The thermally conductive contact member may be flat, curved, convex, concave, deflected, wavy, dimpled, raised, recessed, rough, smooth, or have any other surface geometry sufficient for a particular heat management method. The thermally conductive contact member may be transparent or non-transparent. The thermally conductive contact member may include at least one or more thermally conductive materials known to those skilled in the art, such as thermally conductive silicon, diamond, copper, silicon carbide, graphite, silver, gold, platinum, copper, sapphire, graphene, or silicon oxide, as well as other materials, depending on the desires, needs, or requirements.

[0066] According to one aspect, where the target material is human tissue, the method cools and / or heats the target tissue to a predetermined temperature within a predetermined time, rapidly and precisely cooling and heating the target tissue. FIGS. 2 and 3 are graphs of temperature over time for various embodiments of the thermal management system 100 described above with reference to FIGS. 1A-1C. FIG. 2 shows the rapid temperature response of a method implemented on a gelatin tumor where the contact member 110 is selected to simulate the temperature response within human tissue. In this method, at the starting point, the TEC 120 (FIG. 1B) is driven such that the first portion 122a is cold and the second portion 122b is warm, and the two-phase heat transfer unit 140 is operated to remove heat from the second portion 122b of the TEC 120. The TEC 120 is then reversed such that the first portion 122a is warm and the second portion 122b is cold, causing a rapid spike in temperature from 0° C. to over 20° C. within seconds. The TEC 120 can then be reversed again such that the first portion 122a cools the contact member 110 again and rapidly drops the temperature back to the starting level. In addition to the rapid increase and decrease in temperature, this test also shows that the specific target temperature can be precisely achieved and controllably maintained without overshoot or undershoot.

[0067] FIG. 3 shows another temperature / time plot of temperature at various depths of 2 mm, 5 mm, and 10 mm within the target material that simulates human tissue. As shown, the embodiments of the thermal management system 100 described above with reference to FIGS. 1A-1C were able to recover sufficient heat to lower the temperature from about 25° C. to 0° C. within 9 minutes at a depth of 2 mm, within 15 minutes at a depth of 5 mm, and within 20 minutes at a depth of 10 mm. This is a surprising result for a thermal management unit having the small and thin form factor shown in FIGS. 1A-1C. This is particularly useful for medical and aesthetic treatments as smaller and lighter applicators can be used, which allows more complex areas of the body to be cooled and provides more comfort to the patient.

[0068] Figure 4 shows another temperature and time plot of a simulated tissue that is cooled and heated using the thermal management system according to the present technology. The target material 101 is initially at a normal physiological temperature TT1 (tissue temperature) of about 35°C. As shown in Figure 4, the tissue to be treated is at different temperatures as a function of tissue depth, and Figure 4 shows the initial temperatures at the skin contact point, 0.1 mm, 0.5 mm, and 1 mm depths. The temperature at the midpoint of the TEC between the first and second portions 122a-b is also shown by line TE. Also shown are a temperature of about 8°C below which cooling provides an anesthetic effect and a temperature of about -2°C at which the tissue is superficially frozen. The thermal cooling and heating device is at an initial temperature DT1 of about 20°C room temperature or ambient temperature. According to one optional aspect, the device may be warmed to a pre-contact temperature DT2 of about 35°C to alleviate the uncomfortable contact of a relatively cold device to a relatively warm patient. The device at temperature DT1 is then brought into contact with the skin surface, the TEC is activated, and within about 2 seconds, cools the target material from 20°C to about -2°C or from 20°C to about -10°C, providing the cooling to the skin. After about 5 seconds, the electricity flows through the device in one direction, cooling the device and thereby cooling the temperature at the skin contact point (skin contact green line) to about -2°C within about 3 seconds. The tissue at a depth of 0.1 mm is cooled to a temperature of about 2°C within about 8 seconds. The temperature of the tissue at depths of 0.5 mm to 1.0 mm is higher and above the temperature at which cooling can provide an anesthetic effect. At this point, the skin can be treated, for example, using a laser beam, and the skin at the contact surface and at a depth of 0.1 mm enjoys the benefit from the anesthetic effect from the cooling. At this point, the direction of the current is reversed so that the device heats the skin to a temperature of about 30°C at the skin contact point and about 27°C at a depth 0.1 mm below the surface within about 2 seconds. At this point, the direction of the current is reversed again and cools the skin to a temperature of about -2°C within about 3 seconds, and the skin can be treated, for example, using a laser beam.

[0069] Some aspects of the present technology, such as rapid temperature changes and precise control of the temperature of the target material 101, are enabled by the high heat transfer rate despite the small size of the heat transfer unit 140 compared to the TEC 120 and / or the contact member 110. In some embodiments, only the TEC 120 and the contact member 110 or the TEC 120 alone have a first volumetric heat capacity, and the heat transfer unit 140 has a second volumetric heat capacity that does not exceed one of 50%, 100%, 150%, 200%, 250%, 300%, 400%, or 500% of the first volumetric heat capacity. More specifically, the first volumetric heat capacity of the heat transfer unit 140 is only about 50% - 200% or 100% - 150% of the second volumetric heat capacity of the TEC 120 alone or the combination of the TEC 120 and the contact member 110.

[0070] This cycle can be repeated any number of times to treat the target tissue and at different target tissue locations. For example, the device can be used to cool a first target tissue location TL1 to a temperature of about 8°C, at which an anesthetic effect is achieved at the surface or 0.1 mm below the surface within about 2 seconds, and to a temperature of about -2°C, at which superficial freezing occurs, within about 3 seconds. The tissue TL1 can be treated, for example, using laser light, and then the tissue TL1 can be heated to a temperature of about 30°C or 20°C or 15°C within about 2 seconds. The device can then be moved to a second tissue location TL2, and the tissue can be cooled to an anesthetic treatment temperature within about 2 - 3 seconds for treatment using laser light. The second tissue location can then be heated to about 30°C within about 2 seconds, and the device can be moved to a third tissue location TL3, where the cooling, treatment, and heating cycles are performed. This cycle can be performed on any number of tissue locations TL Ncan be repeated. An additional cooling and / or heating profile can be executed using the thermal management system described herein. For example, the cooling or heating profile may be a pulse or a sine wave pulse of a cooling (temperature decrease) or heating (temperature increase) effect. Cooling and / or heating may be accomplished by a desired electrical pulse or current through a thermoelectric unit, which may be reversed as described herein. According to one embodiment, cooling and / or heating may be accomplished by controlling the fluid pressure or flow rate to a heat transfer unit, such fluid pressure or flow rate being used to remove heat from a heat source in contact with the heat transfer unit.

[0071] FIG. 5 is a graph showing the heat flux across TEC120 at the point where the current is reversed at 8 seconds, 10 seconds, and 13 seconds. As shown in FIG. 5, the high heat flux changes in less than 1 second, which reflects the rapid cooling and heating of TEC120 and the rapid cooling and heating of the target material 101. According to one aspect, the target material to be cooled and / or heated is the tissue of a patient undergoing a treatment such as an energy-based treatment like laser treatment for hair removal or dermatological treatment or needle injection, etc. Other treatments within the scope of the present technology include radiotherapy for cancer treatment, thermotherapy (such as cryotherapy or hyperthermia), combined thermotherapy and immunotherapy, acne treatment (long pulse), body slimming by cooling subcutaneous adipose tissue, invasive or non-invasive RF treatment, HIFU, ultrasound, laser tattoo removal, ablative laser skin rejuvenation, cellulite treatment, depigmentation, and skin rejuvenation. According to such treatments, the tissue is cooled to paralyze the tissue before, during, or after such treatment to reduce pain during the treatment. According to one aspect, the tissue is cooled to paralyze the tissue before, during, or after laser or needle treatment to reduce pain during the treatment. Thus, the thermal cooling or heating device provides an anesthetic effect. After cooling, the tissue may be heated to bring the tissue to a higher temperature such as the normal tissue temperature. Since the device is intended to contact the tissue, the device may be heated to the normal tissue temperature, such as when a cryogenic device is placed against the warm tissue of a patient, to provide a comfortable contact to the patient and avoid an uncomfortable contact.

[0072] According to one aspect, a device for cooling tissue as described herein is integrated into a laser system or other medical device to protect the epidermis, reduce pain within the treatment area, and / or prevent damage to non-target tissue (e.g., the skin adjacent to the target tissue). The device also provides temporary local anesthesia relief for laser treatment and injection, thereby improving the effectiveness of the laser or other medical device. With respect to the timing of laser irradiation or operation of the medical device, the cooling can occur before, during, or after the treatment, which includes pre-cooling, concurrent cooling, and post-cooling.

[0073] The primary objective of laser therapy for patients suffering from specific skin diseases is to maximize thermal damage to target pigment cells while minimizing damage to normal skin. However, in some cases, the threshold dose of the incident laser beam for epidermal damage can be very close to the threshold for pigment cell removal. Patients with dark skin are more susceptible to these problems due to high epidermal melanin, which competes as a significant pigment cell for laser energy, leading to increased pain, blister formation, scarring, and abnormal pigmentation. The device for heating and cooling tissue described herein can selectively cool the outermost layer of the skin and reduce pain, blister formation, scarring, and abnormal pigmentation. The goal is epidermal cooling to prevent temperature rises above the threshold temperature that cause thermal damage. Cooling allows high fluence laser beams to be delivered to the skin to protect the epidermis. This is referred to as the theory of spatial selectivity of cooling. To target pigment cells within blood vessels, stem cells, hair follicles, etc., the treatment temperature should be reached. However, the treatment temperature will often damage epidermal keratinocytes and melanocytes. The device for cooling and heating the skin described herein can maintain a lower temperature at the epidermal level but reach the higher treatment temperature required at the target depth within the tissue, which often provides a better outcome for laser procedures. In addition, cooling will often reduce the amount of edema that develops as a complication of laser procedures. Thus, the thermal management system of the present technology can protect the superficial layer of the skin from accompanying thermal damage.

[0074] Some embodiments of the thermal management system according to the present technology are integrated components on the surface of a handheld medical device, or the thermal management system may be a separate component that can be attached to the medical device. For example, the thermal management system can be added to a laser, including a handheld laser emission device such as the Candela GentleLASE Plus laser, which is a non-invasive phototherapy device specifically designed to remove unwanted hair from all parts of the body. The Candela GentleLASE Plus generates intense, focused pulses of light that are directed through a small handpiece to the treatment site. According to one aspect, the thermal management system may be machined at the tip of the handpiece of such a commercially available laser system. After the skin is cooled using the thermal management system to protect the skin and provide an anesthetic effect, the laser energy passes through the thermal management system and through the skin to the hair follicles, and the energy is absorbed by the hair and the pigment in the hair follicles. As a result, the hair roots are selectively damaged without damaging the delicate pores and structures of the skin. The laser is pulsed, i.e., "turned on," for less than one second. The pulse duration is carefully calibrated so that the laser energy will be absorbed by the hair follicles without transmitting excessive heat to the surrounding skin. Then, the thermal management system warms the skin and then is moved to a second target skin location, and the process is repeated.

[0075] According to one aspect, the thermal management system cools the tissue in response to contact and may be referred to as contact cooling therapy. According to one aspect, the thermal management system has a transparent component or material that may allow light to pass through it while in contact with the tissue, such as when the thermal management system cools or heats the tissue. According to another aspect, the thermal management system has channels or holes through it that may allow light or another treatment modality or tool to pass through it while the thermal management system is in contact with the tissue.

[0076] According to certain aspects of the present technology, a thermal management system can also controllably compress the skin / tissue, cooling the tissue while reducing blood flow within the target material, and thus reducing oxyhemoglobin, which is an active chromophore. Additionally, skin compression brings deeper targets, such as hair follicles, closer to the skin surface, which improves the absorption of laser energy, and thus less fluence can be used to heat the thermal target and / or more energy can reach the target.

[0077] The thermal management system of the present technology is thus generally useful in treatment methods related to dermatological treatments, including hair removal, tattoo removal, acne treatment, ablative laser treatment, invasive and non-invasive RF treatment, radiation therapy such as radiation beam therapy for treating cancerous tissues such as tumors. The thermal management system can be activated before, during, and after treatment. According to one aspect, the thermal management system can be used to induce localized thermal damage to tumor tissue throughout a desired surface area or at individual locations or points within a given tissue surface area. For example, within a given tissue surface area, the tissue may have no or little thermal damage and may also have locations of thermal damage. The locations of thermal damage may be ordered or random as desired according to the treatment.

[0078] FIG. 6 illustrates an embodiment of a thermal management system 600 for cooling a target material 101 in conjunction with primary therapy. The thermal management system 600 can be similar to the thermal management system 100 described above, and like reference numerals refer to similar or identical components. The thermal management system 600 can include a thermally conductive contact member 110 and TECs 120 such that several TECs 120 are thermally coupled to the contact member 110. The TEC 120 has an electrical contact pad 610 in a first portion 122a and a contact pad 620 in a second portion 122b, and current can flow between the contact pad 620 and the contact pad 610 to cool the first portion 122a of the TECS 120, while heat flows in the opposite direction as indicated by the arrows within the target and within the TEC 120.

[0079] The thermal management system 600 includes a two-phase heat transfer unit 640 that is thermally coupled to the TEC 120. The heat transfer unit 640 can be similar to the heat transfer unit 140 described above. For example, the heat transfer unit 640 can have a base 642, an upper portion 644, and a phase change chamber 646 that defines a vapor space within the space between the base 642 and the upper portion 644. The heat transfer unit 640 can further include micro features 652, such as pins or extended panels, that define micro channels 654. The micro features 652 can be superimposed with the corresponding TEC 120, as shown in FIG. 6. During operation, the working fluid within the micro channels 654 evaporates and cools the TEC 120.

[0080] The base 642 and the upper portion 644 can be made of a transparent material, such as sapphire, diamond, glass, transparent ceramic, alumina, a transparent polymer nanocomposite with crystallized alumina, or can have a transparent portion. As a result, the thermal management system 600 is well-suited to be used in combination with lasers and other skin treatment devices. During operation, a laser beam or other radiation beam can pass through the transparent upper portion 644 and the base 642 and through the area between the TECs 120 to heat a target tissue at a certain depth within a tissue, such as a hair follicle or collagen, while the TEC 120 and the heat transfer unit 640 cool the epidermis and dermis where nerves are located. As a result, the laser treatment can heat the target tissue to a higher temperature over a longer time period and improve the treatment outcome, while the thermal management system 600 cools the skin surface, protects the skin from burns, and alleviates or further reduces pain.

[0081] FIG. 7 is an isometric view of the thermal management system 600 of FIG. 6 during operation. The volume of the tissue 700 is shown in the X-Y-Z directions and includes fat and skin. The surface of the skin is at position 0 and the depth of the tissue is shown. The thermally conductive and transparent contact member 110 contacts the skin, and the TEC 120 as described herein is thermally coupled to the contact member 110. The two-phase heat transfer unit 640 as described herein is thermally coupled to the TEC 120. During operation, the laser 660 or other treatment modality (e.g., an external beam radiation device) directs the energy beam 662 through a transparent component within the space between the TECs 120.

[0082] FIG. 8A illustrates a side view of the thermal management system 800, and FIG. 8B is a top view of the thermal management system 800. The thermal management system 800 includes a contact member 110, a TEC 120 thermally coupled to the contact member 110, and a two-phase heat transfer unit 840 thermally coupled to the TEC 120. A liquid-phase working fluid flows through a first conduit 850 to the heat transfer unit 840, and a vapor phase of the working fluid flows from the heat transfer unit 840 through a second conduit 862. The heat transfer unit 840 can be similar to the heat transfer unit 140, but the heat transfer unit 840 includes an access hole 842, and the contact member 110 has an opening 844 that aligns with the access hole 842. The access hole 842 and the opening 844 are at least generally aligned with the space between the TECs 120.

[0083] During operation, an energy beam 860, such as a needle or a laser beam, a radiation beam, or another type of beam, is directed through the access hole 842 and the opening 844. According to one aspect, the access hole 842 and the opening 844 also enable vapor and / or tissue debris to be expelled from the surface of the target material during treatment, such as ablation laser treatment. Thus, the thermal management system 800 need not be removed during treatment of the target material. The system 800 can also include a temperature sensor 870 at or near the TEC120. According to one aspect, depending on the application, the two-phase heat transfer unit 840, the TEC120, and the high-conductivity contact member 101 are made of a specific material that is transparent to a portion of the electromagnetic wave spectrum.

[0084] According to one aspect, a vacuum system may be used to secure any one of the thermal management systems 100, 600, 800 described above to the surface of the target material during treatment. The vacuum system is used to maintain or improve thermal contact with the target material, such as the skin. According to one aspect, the same vacuum system or a separate vacuum system may be used to evacuate or contain any tissue debris and vapor that may be generated during ablation energy-based treatments, such as ablation carbon dioxide treatment. According to one aspect, securing the thermal management system 100, 600, 800 to the skin surface during treatment prevents debris from an ablation laser treatment from clogging the access holes, which may be present within the thermal management system. The vacuum system also contains any vapor or debris, thereby preventing debris, particles, and gases from being inhaled by the patient or the system operator. The vacuum system also helps to reduce blood flow within the skin, which is useful for both laser procedures and treatments for reducing subcutaneous adipose tissue for body sculpting.

[0085] FIG. 9 is a schematic diagram of a thermal management system 900 having a TEC 120 and a heat transfer unit 940. The heat transfer unit 940 has an array of microchannels 962 arranged such that a discrete group of microchannels 962 is aligned with an individual TEC 120. The microchannels 962 can generally be connected to an inlet or an outlet by a common duct 964. The heat transfer unit 942 further includes an optional access hole 942 and a temperature sensor 970 located at different positions and layers throughout the system and providing a feedback signal for controlling the heat flux and temperature at the device-target interface. Each thermal management system 900 can be an individual cell.

[0086] FIG. 10 is a schematic diagram of an assembly 1000 of several thermal management systems 900. The assembly 1000 includes a fluid delivery line 1010 capable of transporting the liquid phase of a working fluid to individual thermal management systems 900. The number and arrangement of the TECs as well as the microchannels can be varied according to any specific application. A cap (not shown) covering the channels provides the space required for the vapor to exit the system. In some configurations, the vapor is purged to the ambient (e.g., an open system that can be used in combination with any embodiment herein), while in other configurations, the vapor is countercondensed to the liquid phase within a closed system. The interface between the thermal management system 900 and the target can be flat or curved with a specific surface profile for any particular application. The thermal management system 900 is made of a flexible material and can be conformal to the shape of the target. The thermal management system 900 also includes a heating element and can rapidly increase the temperature at the target-system interface when required. The system can operate at pressures from 0.0001 bar to 20 bar and temperatures from -270 °C to 1,000 °C.

[0087] FIG. 11 is a schematic diagram of another assembly 1100 of several thermal management systems 900. In this embodiment, the individual thermal management systems 900 do not have access holes and instead have a solid central region 1110. The central region 1110 can be a transparent material, and thus, laser light or other radiation beams can be transmitted through the central area to the underlying target material.

[0088] FIG. 12 is a schematic diagram of a semiconductor assembly 1200 having a semiconductor device 1201 and the thermal management unit 100 described above with respect to FIGS. 1A - 1C. The thermal management system can alternatively have a heat transfer unit as described with respect to FIGS. 15A - 20E herein. The semiconductor device 1201 can be a processor, a memory device, a light emitting diode, or other heat producing device. In this embodiment, the contact member 101 is attached to the semiconductor device 1201.

[0089] FIG. 13 is a schematic diagram of a semiconductor assembly 1300 having a semiconductor device 1301 and a version of the thermal management system 100 without the contact member 110. The thermal management system can alternatively have a heat transfer unit as described with respect to FIGS. 15A - 20E herein. In this embodiment, the semiconductor device has a passivation material 1302, and the TEC 120 of the thermal management system 100 is attached to the passivation material 1302.

[0090] FIG. 14 is a schematic diagram of several devices 1401a-n (collectively referred to as device 1401), such as a server, cooled using the thermal management system according to the present technology. Each device 1401 can have a semiconductor assembly similar or identical to the semiconductor assemblies 1200 and 1300 described above, or each device 1401 can have separate thermal management systems 100, 600, 800 attached to the housing of device 1401 in addition to, or instead of, a thermal management system attached to the semiconductor device. Additionally, the thermal management system can alternatively have a heat transfer unit as described with respect to FIGS. 15A-20E of this specification. Assemblies 1200 and 1300 can each be coupled to a common condenser 180. In operation, assemblies 1200 and 1300 can be cooled internally using the thin thermal management system 100, reducing or eliminating the need for a large-scale cooling air flow across device 1401. This can save a significant amount of energy and cool many servers compared to conventional air-cooled servers. This can, therefore, also simplify the construction and maintenance of larger server farms.

[0091] Any of the foregoing heat transfer units is described in U.S. Patent No. 10,217,692 (incorporated herein by reference in its entirety), and specifically may include aspects of the evaporation structure with respect to the teachings of the design for a two-phase evaporation cooling unit. For example, the evaporation structure may include a series of protrusions that extend downward from a base into the evaporation fluid. Alternatively, the evaporation structure may include a series of walls that form a series of channels that accompany the evaporation fluid therebetween. The evaporation structure may include a porous material configured to receive the evaporation fluid. The evaporation structure may include a wall having a fractal topography configured to receive the evaporation fluid. The evaporation structure is designed to facilitate the evaporation of the working fluid and cool the TEC. The evaporation structure is operably connected to an inlet conduit or port and an outlet conduit or port to operably provide an evaporation fluid flow path through the evaporation structure. According to one embodiment, the inlet conduit is operably connected to a pump and reservoir of the evaporation fluid to pump the evaporation fluid through the evaporation structure. The inlet conduit is configured to receive the evaporation fluid as it enters the evaporation structure. The outlet conduit is configured to receive the evaporation fluid as it exits the evaporation structure. The evaporation structure or a separate condenser may also include a condensation plate or unit, as known in the art, to condense the evaporated evaporation fluid for collection and / or redistribution to the evaporation unit. The evaporation structure may contact a plurality of TECs such that a single evaporation structure cools the plurality of TECs.

[0092] The heat transfer unit according to the present technology may alternatively include other two-phase cooling devices such as Joule-Thompson cooling devices, spray cooling devices, and equivalents. Such heat transfer units include, for example, cryogen spray (dynamic) cooling such as pulsed cryogen spray using non-toxic 1,1,1,2-tetrafluoroethane (boiling point: -26.2 °C), also known as R-134a, or liquid nitrogen or liquid carbon dioxide. Other materials useful for cooling include HFOs, HFCs, nitrous oxide, alcohols, hydrocarbons (isobutane, propane, etc.), water, ammonia, particle-fluid mixtures, two-component (or more) mixtures of materials (or fluids), and equivalents. The heat transfer unit may take the form of a container pressurized with a gas or fluid, which, when released or sprayed onto the surface of the hot side of the thermoelectric unit, causes cooling of the thermoelectric unit. When the contents of the container or cartridge are empty, the container or cartridge may be discarded and a new full container or cartridge may be used in combination with the system as the heat transfer unit. The heat transfer unit according to the present technology transfers the heat generated by the TEC, which is dissipated away from the TEC, thereby enabling the TEC to cool the target material or otherwise adjust its temperature in the cooling mode of the system. Advantageously, the heat transfer unit prevents the TEC from overheating, where the heat generated by the TEC exceeds the cooling capacity of the TEC.

[0093] The two-phase heat transfer unit described in U.S. Patent No. 10,217,692 operates based on the principle of evaporative cooling. One embodiment includes a reservoir configured to contain a working fluid, a base member in communication with and adjacent to a heat source, and an elongating member extending distally away from the base member and configured to form a passageway between the elongating members, the elongating member including a proximal region and a distal region, the distal region of the elongating member being at least partially inserted or immersed in the working fluid, a two-phase heat transfer device.

[0094] According to one aspect, the two-phase heat transfer unit includes a reservoir configured to contain a working fluid and a base member having a first face and a second face, the first and second faces generally facing each other, the first face of the base member being in thermal communication with and configured to be adjacent to a heat source such as a TEC as described herein. The extension members extend distally away from the second face of the base member and are configured to form a passageway between the extension members, the extension members including a proximal region and a distal region, the distal region being configured to be at least partially inserted into the working fluid, the passageway being configured to contain vapor that can be produced from the working fluid so as to define a vapor space. The extension members may be protrusions, walls, panels, pins, struts, or rods, and any combination thereof. The base member and the extension members may be made of a thermally conductive non-porous solid such as silicon, diamond, copper, silicon carbide, graphite, silver, gold, platinum, copper, or silicon oxide, and other materials, as desired, necessary, or required. It should be understood that the base member and the extension members, particularly the distal region, may be at least partially made of a porous material. The working fluid may include water, oil, metal, octane, hydrocarbon, pentane, R-245ca, R-245fa, isopentane, halogenated hydrocarbon, halogenated alkane, HFO, HFC, ketone, alcohol, or alkali metal, and other materials, as desired, necessary, or required.

[0095] Aspects of certain embodiments provide, but are not limited to, a two-phase heat transfer device. The device includes a reservoir configured to convey a working fluid, a base member having a first surface and a second surface, the first and second surfaces generally being spaced apart from each other, the first surface of the base member being configured to receive thermal energy from a heat source, an elongating member extending distally away from the second surface of the base member and configured to define individual passages between adjacent elongating members, the elongating member including a proximal region and a distal region, the distal region being configured to be at least partially inserted into the working fluid, and the passages being configured to contain vapor produced from the working fluid so as to define a vapor space.

[0096] According to one aspect, a two-phase heat transfer unit includes a reservoir configured to convey a working fluid, a base member configured to receive thermal energy from a heat source, and an elongating member extending distally away from the base member and configured to define individual passages between adjacent elongating members, the elongating member including a proximal region and a distal region, the distal region being configured to be at least partially inserted into the working fluid, and the passages being configured to contain vapor produced from the working fluid so as to define a vapor space.

[0097] According to one aspect, a two-phase heat transfer unit includes a reservoir configured to convey a working fluid, a base member configured to receive thermal energy from a heat source, and an elongating member extending distally away from the base member and configured to define individual passages between adjacent elongating members, the elongating member including a proximal region and a distal region, the distal region being configured to be at least partially inserted into the reservoir.

[0098] According to one aspect, a two-phase heat transfer unit includes a reservoir configured to transport a working fluid, a base member configured to receive thermal energy from a heat source, and an elongating member that extends distally away from the base member and is configured to define individual passages between adjacent elongating members, wherein at least some of the elongating members are configured to be inserted at least partially into the reservoir.

[0099] According to one aspect, a two-phase heat transfer unit includes a reservoir configured to transport a working fluid, a base member configured to receive thermal energy from a heat source, and an elongating member having at least one wall, the elongating member extending distally away from the base member and being configured to define individual passages between adjacent elongating members, the elongating member including a proximal region and a distal region, the distal region being configured to be inserted at least partially into the working fluid, and a recessed topography disposed on at least one wall of the elongating member, the recessed topography being configured to contain the working fluid, the passages being configured to contain vapor produced from the working fluid so as to define a vapor space.

[0100] A two-phase heat transfer device according to any of the embodiments described with reference to FIGS. 1A - 20E provides high evaporation and cooling capacity for use in combination with a TEC when cooling a target material. Advantages associated with such a two-phase heat transfer device include increased cooling capacity per unit area, controlled and optimized evaporation, prevention of boiling, and prevention of evaporator dry-out. Aspects associated with one approach may include, but are not limited to, the use of a recessed topology to increase the suction of the working fluid in the direction towards the heat source. Aspects associated with one approach may include, but are not limited to, the use of a non-wetting coating or structure to keep the working fluid away from the space between the elongating members of the evaporator and the use of a wetting coating or structure to form a thin film of the working fluid around the distal region of the elongating member.

[0101] The two-phase heat transfer device may utilize any combination of a wetting coating, a wetting target material, a non-wetting coating, or a non-wetting target material to attract a working fluid to an area of the device and repel the working fluid from an area of the device. For example, the device may include a wetting coating, such as a hydrophilic coating or a lyophilic coating, disposed on the distal region of the elongate member to attract the working fluid. Alternatively, the distal region of the elongate member may be composed of a wetting target material (i.e., material), such as a hydrophilic target material or a lyophilic target material. In another embodiment, the device may include a non-wetting coating, such as a hydrophobic coating or a lyophobic coating, disposed on the proximal region of the elongate member and on a second surface of the base member located between the elongate members to repel a liquid working fluid. Alternatively, the proximal region of the elongate member and the second surface of the base member located between the elongate members may be composed of a non-wetting target material (i.e., material), such as a hydrophobic target material or a lyophobic target material.

[0102] The two-phase heat transfer unit may include a vapor space defined by a passageway that expands in the direction of vapor flow. For example, the passageway may extend radially from a central region, and the path is radial from the central region. In another embodiment, the expanding vapor space is formed by reducing the number of elongate members (e.g., per unit length / area) in the direction of vapor flow. Alternatively, the passageway may have a width that is uniform or narrowing. Alternatively, the passageway may have a width that can provide a combination of expanding and narrowing as well as remaining uniform.

[0103] Figures 15A - 15E show a thermal management system 1500 having a contact member 110, a TEC 120, and a two - phase heat transfer unit 1502 (also referred to herein as "heat source 1501") for cooling and / or heating a target material 1501 which can be any of the target materials disclosed above. Referring to Figure 15A, the two - phase heat transfer unit 1502 has a phase - change chamber 1504 (also referred to herein as reservoir 1504) containing a working fluid 1505, a base 1506 in contact with the TEC 120, and micro - features 1514 (also referred to herein as extension members 1514) protruding from the base 1506 and forming a passage 1520. Figure 15B is an enlarged partial view of a single passage 1520 (also referred to as a channel) of Figure 15A, and Figure 15C shows an enlarged partial view of the thin - film region of the meniscus 1503 of the working fluid 1505 shown in Figures 15A and 15B. The evaporative thin - film region of the meniscus 1503 is the location where most of the evaporative heat transfer occurs because this region of the meniscus 1503 has a very thin thickness and thus a high conductive resistance. The non - evaporative thin - film region, if it exists, is the location where the adhesive force between the liquid molecules and the solid surface is extremely strong because only a few molecules can transfer from the liquid phase to the gas phase. Thus, the evaporative thin - film region represents a region of enhanced evaporation and heat transfer.

[0104] The working fluid may be water, oil, metal, octane, hydrocarbon, pentane, R - 245ca, R - 245fa, isopentane, halogenated hydrocarbon, halogenated alkane, HFO, HFC, alkene, ketone, alcohol, or alkali metal. It should be understood that the working fluid 1505 should be compatible with other materials that make up the device such that they will not chemically react and produce non - condensable gases or cause other harmful effects. Further, by way of example, the working fluid may be any liquid or gas. Further, the working fluid may be a molten metal or liquid metal such as lithium or the like.

[0105] The extension member 1514 can extend away from the base member 1506 in a direction opposite to the target material 1501, and the distal region of the extension member 1514 is partially immersed or inserted into the working fluid 1505. Heat travels through the solid mass of the base member 1506, follows the microfeature 1514, and proceeds directly to the evaporative thin film region of the meniscus 1503 where most of the evaporative heat transfer occurs. Heat is thus more readily provided to the evaporative thin film region, which in turn eliminates or at least reduces the potential for boiling within the passageway 1520 so that ordered and efficient evaporation can be continuously maintained.

[0106] The two-phase cooling device can be designed to operate in any orientation, assuming the orientation of the target material to be cooled or heated. For example, the two-phase cooling device may be designed to be insensitive to gravity (i.e., omni-directional) when the channel width or spacing between pins is smaller than a certain size such that surface forces (capillary forces) are dominant compared to such volumetric forces of gravity. A non-wetting coating can be used to repel the liquid from entering that space in order to avoid capillary forces that draw the liquid into the space between the pins or the channel spacing, thereby reducing or eliminating the vapor space. According to an additional embodiment, the target material, such as tissue, may be below or above the two-phase cooling device.

[0107] Still, generally referring to FIG. 15A, another advantage (but not limited thereto) of the present and other embodiments of the two-phase heat transfer device is the efficient delivery of the liquid-phase working fluid to the evaporation site. Since the liquid phase of the working fluid 1505 is delivered to the reservoir of the phase change chamber 1504 with only the tip of the microfeature 1514 disposed or immersed therein, the two-phase device does not need to overcome the high shear friction associated with flowing the liquid phase of the working fluid through a large number of narrow channels in a conventional two-phase device. Thus, the drying problem is significantly reduced because there is little resistance in delivering the liquid working fluid 1505 to the phase change chamber 1504 to replenish the evaporated mass.

[0108] As schematically reflected in the block diagram of FIG. 15D, the vapor region 1522 (i.e., where most of the evaporative heat transfer occurs) is adjacent to the heat source. On the other hand, the liquid phase of the working fluid is, among other advantages, relatively far from or remote from the heat source, avoiding or mitigating boiling within the device and enhancing the flow of the liquid working fluid.

[0109] FIG. 15E schematically illustrates a general circuit of the heat flow HF proceeding within an embodiment of the two-phase heat transfer unit 1540 of FIG. 15A. Heat from the heat source proceeds through the solid mass of the microfeatures 1514 (see FIGS. 15A - 15C), across the vapor space 1522 (see FIGS. 15A and 15B), and toward the region of the thin liquid film and the native liquid meniscus. The liquid phase of the working fluid 1505 within the reservoir is located farthest from the heat source, thereby requiring the maximum distance for the heat to proceed. Thus, the thin liquid film and the native liquid meniscus are relatively close to the heat source. The alignment as schematically shown in FIG. 15E enables the heat transfer device to generate superheated vapor without inducing boiling within the native liquid meniscus and the liquid reservoir. Thus, this feature improves the quality of the heat removed by the heat transfer device and the efficiency of the heat transfer device, which can be integrated in various cooling applications as disclosed herein. Further, due to this arrangement, the proximal portion of the solid mass of the microfeatures 1514 (see FIGS. 15A - 15C), i.e., the temperature of the "wall", is higher than the saturation temperature of the thin liquid film and the native liquid meniscus. This prevents the accumulation of the liquid condensate within the vapor space 1522 (see FIGS. 15A and 15B), eliminating or reducing the blockage of the vapor space 1522 by the liquid condensate.

[0110] Figures 16A - 16E schematically illustrate additional embodiments of a phase change thermal management system 1500 that removes heat from a target material 1501. For example, the heat source 1501 can be the surface of a computer chip as well as any of the other heat dissipation applications disclosed herein. The target material 1501 communicates with a first surface 1508 of a base member 1506, and a second surface 1510 of the base member is on the opposite side of the first surface 1508. The microfeatures 1514 extend distally away from the second surface 1510. For example, the base member 1506 and the microfeatures 1514 (or a portion thereof) may comprise a thermally conductive non-porous solid such as, but not limited to, silicon, diamond, copper, silicon carbide, graphite, silver, gold, copper, titanium, platinum, graphene, or a metal alloy. Additionally, or in combination, the base member 1506 and the microfeatures 1514 (or a portion thereof) may have a coating such as, but not limited to, gold, platinum, copper, graphene, or silicon oxide.

[0111] The microfeature 1514 can be a pin, strut, rod, wall, panel, or other structure that efficiently conducts heat and can be constructed to have a desired spacing between the microfeatures 1514. Referring to FIG. 16A, the portion of the microfeature 1514 closer to the base member 1506 defines a proximal region 1516, and the portion farther from the base member 1506 defines a distal region 1518. The distal region 1518 is at least partially submerged in the working fluid 1505, creating a thin film of the working fluid 1505 around the distal region 1518. Heat flow 1513 proceeds (i.e., conducts) from the target material 1501 through the base member 1506 and the proximal region 1516 to the distal region 1518, and heat is removed from the proximal region 1516 and / or the distal region 1518 when controlled evaporation of the working fluid occurs within the thin film area around the distal region 1518. The evaporated liquid produces vapor that fills the passageway 1520 between the microfeature 1514 and the base 1506. Heat is transferred from the device as the vapor proceeds through the passageway 1520 defined by the microfeature 1514 within the vapor path 1521 toward a condenser (not shown). The passageway 1520 may be a channel such as, for example, a microchannel or a nanochannel.

[0112] FIG. 16A shows an embodiment in which the microfeature 1514 is substantially straight. In such an embodiment, the proximal region 1516 of at least one microfeature 1514 has a cross-section that is substantially equal to the distal region 1518. FIG. 16B is an enlarged view of the passageway 1520 shown in FIG. 16A, particularly the vapor space 1522 and the height H, which is the height of the extension member or the passageway E , the height H, which is the height of the vapor space V , and the width W, which is the width of the passageway (i.e., between the extension members 1514). The stippled pattern representing the vapor space 1522 is shown only in the rightmost passageway 1520, but it should be understood that the vapor space 1522 is applicable to any passageway 1520 (such as, but not limited to, a channel or a microchannel).

[0113] FIG. 16C shows another embodiment of the proximal region 1516 of the microfeature 1512 that is wider than the distal region 1518. The microfeature 1514 may thus be formed in various shapes and contours. The passageway 1520 may be a channel such as a microchannel or a nanochannel. FIG. 16D is an enlarged partial view of the passageway 1520 shown in FIG. 16C, showing the vapor space 1522 and the height H, which is the height of the extension member or the passageway. E The height H, which is the height of the vapor space V and the dimensions of the passageway 1520 such as the width W, which is the width of the passageway (i.e., between extension members, for example). The dotted pattern representing the vapor space 1522 is shown only in the rightmost passageway 1520, but the vapor space 1522 is applicable to any passageway 1520 (which may be, but is not limited to, a channel or a microchannel, etc.).

[0114] Although not desiring to be constrained by any limits, the dimensions of the device as well as the dimensions and spacing of the microfeatures 1514 may be any of the aforementioned dimensions described above with respect to FIGS. 1A - 1C. Additionally, various embodiments may have passageways (e.g., channels) with the following dimensions. That is, the width W may range from about 100 nanometers to several hundred microns, the length L may range from about 1 micron to 100 centimeters, and the height H may range from about 5 microns to 5 millimeters. In other examples, the width W may range from about 10 nanometers to 10 millimeters, the length L may range from 100 nanometers to 1,000 centimeters or more, and the height H may range from 100 nanometers to several tens of centimeters. Any of these dimensions is applicable to any of the passageways, regardless of the structure (shape, angle, contour) of the extension members that define the passageway. The dimensions may vary relative to each other between individual passageways. Further, the dimensions may vary within a given passageway itself. Again, these dimensions are merely illustrative.

[0115] The vapor space 1522 is the space within the passageway 1520 that is filled with vapor during operation. The vapor space 1522 can be defined as the space between the surface of the microfeature 1514, the surface of the second face 1510 of the base member 1506, and the surface of the working fluid 1505 (e.g., the meniscus 1503 of the working fluid 1505). The vapor space 1522 can be generated by repelling the working fluid 1505 from the passageway 1520 via the proximal region 1516 of the elongating member and the non-wetting coating 1528 on the second face 1510 of the base member. Alternatively, the vapor space 1522 can be generated by causing the proximal region 1516 of the elongating member and the second face 1510 of the base member to be made of a non-wetting material 1530 (i.e., for example, the material of the structure itself or applicable components) and repelling the working fluid 1505 from the passageway 1520. The vapor space 1522 is typically smaller than the passageway 1520 since the working fluid fills a portion of the passageway 1520. Coating the surface of the distal region 1518 with a wetting coating 1524 or making the distal region 1518 of a wetting target material 1526 attracts the working fluid 1505 to the distal region 1518 and fills a portion of the passageway 1520 in the vicinity of the working fluid 1505.

[0116] In some embodiments, the wetting and / or non-wetting properties of the materials ensure proper flow of the liquid phase of the working fluid to the desired area. The wetting / non-wetting coating and / or the target material of the structure itself may include any part (base or extension member) of the device, as desired, necessary, or required. The part may be of any size, area, thickness, or contour, as desired, necessary, or required. Additionally, in some embodiments, the wetting and / or non-wetting properties of the materials used in the heat transfer device ensure proper flow of the working fluid in the gas phase of the working fluid to the area where it is desired for the working fluid to be in the gas phase. The wetting and non-wetting properties may be provided by a coating material or by the inherent properties of the target material, which is the material used to construct the relevant part of the device. The working fluids 1505 should be compatible with the base member 1506 and the microfeatures 1514 or any coating material used, such that they will not chemically react, produce non-condensable gases, or cause other detrimental effects.

[0117] According to one aspect, the wetting coating may be on at least a portion of the distal region 1518 of the microfeatures 1514, and the non-wetting coating may be on a portion of the proximal region 1516 of the microfeatures 1514. Again, the location of the wetting / non-wetting coating (or structure) may vary as appropriate. It should be understood that the two-phase cooling system may include a wetting coating, a non-wetting coating, or both a wetting coating and a non-wetting coating, as desired.

[0118] Examples of materials suitable as a wet coating or a wet target material include, but are not limited to, hydrophilic materials (especially when water is used as the working fluid 1505), and lyophilic materials (especially when a fluid other than water is used as the working fluid 1505). Examples of materials suitable as a non-wetting coating or a non-wetting target material include, but are not limited to, hydrophobic materials (especially when water is used as the working fluid 1505), and lyophobic materials (especially when a fluid other than water is used as the working fluid 1505). Examples of materials suitable for use as hydrophilic / wet materials can include, but are not limited to, the following with respect to a particular group of working fluids, namely, metals, glasses, ceramics, silicon, silicon carbide, and diamond. Examples of materials suitable for use as hydrophobic / non-wetting materials include, but are not limited to, certain polymers, halogenated hydrocarbons, or chemically modified surfaces of metals. Note that wetting characteristics are defined with respect to a liquid-solid pair. Note that in one approach, the exact wetting characteristics of a particular embodiment can be determined by the specific interaction between the selected working fluid 1505 and the selected wet coating and / or wet target material surface (materials) of the extension member or the base member. Thus, for example, the working fluid 1505 and the wet coating can be selected together according to the exact wetting properties of the liquid-solid pair.

[0119] Heat flow 1513 passes through working fluid 1505 through the distal region 1518 of microfeature 1514. The wettability properties of the wetting coating wet the liquid portion of working fluid 1505 to wet the distal region 1518 of microfeature 1514 and create a meniscus within the liquid phase of working fluid 1505. As with other embodiments of the present technology, an evaporative thin film region will be present within a portion of working fluid 1505 that contacts the distal region 1518 of microfeature 1514. Depending on the status of the coating (e.g., the portion, location, and type of the coating), working fluid 1505 may contact the proximal region 1516 of microfeature 1514. High heat transfer is achieved by the ability of continuously active thin film evaporation sites that maximize the latent heat of evaporation of working fluid 1505 (as shown in FIG. 15C and discussed with respect to FIGS. 16A-16D). Additionally, in this particular embodiment, the non-wetting coating inhibits working fluid 1505 from covering or filling (or intruding into) the space surrounded by the proximal region 1516 of microfeature 1514. This allows the space to act as a vapor passage (e.g., a channel or similar structure) for the vapor produced as a result of evaporation and for the flow within that individual vapor path. Additionally, the non-wetting coating allows vapor to flow to the condenser with minimal resistance.

[0120] Creating a vapor space within the passage reduces boiling and foaming. Evaporation occurs in the distal region of the elongating member through controlled thin-film evaporation. Further, in some embodiments, such as those that may utilize a horizontal configuration, the flow of liquid is less restricted as it does not proceed through a narrow passage. The liquid flows at least partially within the open area in the phase transition chamber 1504, resulting in a lower pressure drop. This reservoir may be readily applicable where a horizontal configuration is implemented or where the gravity acting on the fluid within the passage and / or reservoir is essentially negligible. In other orientations, for example, a thoughtful placement of the wick or shaping of the passage may be implemented to induce and assist the flow of liquid. Without wishing to be bound by scientific theory, it is desirable to enable the liquid to flow (freely) within the pool and the vapor to flow within the space between the channel walls or between pins or porous target materials, etc. Vapor has a much lower viscosity compared to liquid. The arrangements described herein reduce the overall pressure drop required to circulate / flow the fluid through the system for both open or closed systems. According to one aspect, the active evaporation portion of the meniscus may be closer to the heat source in a certain configuration. According to one aspect, the thin-film portion of the liquid meniscus is closest to the heat source and is exposed to the highest temperature. This aspect eliminates / reduces the chance of pool boiling within the channel as most of the liquid can remain below the boiling temperature (subcooled) while concentrated evaporation occurs in the upper portion where the thin film is located.

[0121] FIG. 17A schematically illustrates an embodiment of the elongating member 1514 of the device with a wetting coating 1524 and a non-wetting coating 1528. The wetting coating 1524 may be positioned over a portion of the distal region 1518 of the microfeature 1514. In this embodiment, the non-wetting coating 1528 may be positioned over a portion of the proximal region 1516 of the microfeature 1514. Again, the location of the wetting / non-wetting coating (or structure) may vary as appropriate.

[0122] Examples of materials suitable as the wetting coating 1524 or the wetting target material include, but are not limited to, hydrophilic materials (especially when water is used as the working fluid 1505), and lyophilic materials (especially when a fluid other than water is used as the working fluid 1505). Examples of materials suitable for use as the non-wetting coating 1528 or the non-wetting target material include, but are not limited to, hydrophobic materials (especially when water is used as the working fluid 1505), and lyophobic materials (especially when a fluid other than water is used as the working fluid 1505). Examples of materials suitable for use as hydrophilic / wetting materials can include, but are not limited to, the following with respect to the group of working fluids, namely, metals, glasses, ceramics, silicon, silicon carbide, and diamond. Examples of materials suitable for use as hydrophobic / non-wetting materials include, but are not limited to, certain polymers, halogenated hydrocarbons, or chemically modified surfaces of metals. In one approach, the wetting characteristics of certain embodiments may be determined by the specific interactions between the selected working fluid 1505 and the selected wetting coating 1524 and / or the wetting target material surface (material) of the extension member or the base member. Thus, for example, the working fluid 1505 and the wetting coating 1524 can be selected together according to the exact wetting properties of the liquid-solid pair.

[0123] Heat flow 1513 conducts from the distal region 1518 of the microfeature 1514 to the working fluid 1505 in the distal region 1518. The wetting properties of the wetting coating 1524 wet the distal region 1518 of the microfeature 1514 in the liquid portion of the working fluid 1505, generating a meniscus 1503 within the liquid phase of the working fluid 1505. Similar to other embodiments of the present technology, an evaporative thin film region will be present within a portion of the working fluid 1505 that contacts the distal region 1518 of the microfeature 1514. Depending on the status of the coating (e.g., the portion, location, and type of the coating), the working fluid 1505 may be contacted with the proximal region 1516 of the microfeature 1514. High heat transfer is achieved by the ability of continuously active thin film evaporation sites that maximize the latent heat of evaporation of the working fluid 1505 (as shown in FIG. 15C and discussed with respect to FIGS. 16A - 16D).

[0124] In addition, in this embodiment, the non - wetting coating 1528 inhibits the working fluid 1505 from covering or filling (or entering) the space surrounded by the proximal region 1516 of the microfeature 1514. This allows the space to act as a vapor passage (e.g., a channel or similar structure) for the vapor produced as a result of evaporation and the flow within its individual vapor path. In addition, the non - wetting coating 1528 allows the vapor to flow to the condenser with minimal resistance.

[0125] FIG. 17B schematically illustrates an embodiment of an elongating member of the device with a core 1538 (or similar structure) to ensure that the distal region 1518 of the microfeature 1514 remains in constant contact with the liquid phase of the working fluid 1505. The core 1538 may also increase the flow of the working fluid through the elongating member and the passageway. In such an embodiment, the core 1538 may provide capillary attraction to move the liquid portion of the working fluid 1505 from the condenser portion of the device to the evaporator portion. Other approaches such as a system similar to a core or a pumping system may also be used. Such pumping approaches may include electroosmotic pumping that can be used to facilitate flow towards the thin film.

[0126] The core 1538 can ensure the persistence of contact between the distal region 1518 of the microfeature 1514 and the liquid portion of the working fluid 1505 along the entire length of the microfeature 1514. Thus, the capillary attraction of the liquid portion of the working fluid 1505 to the evaporation site along the microfeature 1514 is not impaired, and problems associated with drying are reduced or avoided.

[0127] In other embodiments, the liquid portion of the working fluid 1505 may rely on gravity and be moved from the condenser to the evaporator by being stored in a manner that allows the working fluid 1505 to return to the reservoir within the evaporator. The continuous contact between the distal region 1518 of the microfeature 1514 and the liquid portion of the working fluid 1505 can then be achieved through a combination of wetting and / or non-wetting treatments of the relevant portion of the microfeature 1514.

[0128] Referring now to FIG. 18A, in some embodiments, the microfeature 1514 may generally be constructed to form a vapor passage 1520 that widens along a path 1521 through which the vapor accumulating therein flows. Thus, the passage 1520 formed by the microfeature 1514 can accommodate vapor flow within a number of vapor paths 1521. In this embodiment, the passage 1520 generally widens to accommodate an increasing amount of vapor traveling within its various vapor paths 1521. Near the center of the device, the vapor flow rate is less than that near the edge through which all the accumulated vapor flow passes before exiting from the evaporator towards the condenser. The numerous sides of the extension member, such as, but not limited to, size, shape, area, profile, location or position, number provided, density provided, etc., may be configured and varied. In related manners, the various vapor paths may be configured to be regular or irregular as determined by a particular configuration of the selected extension member.

[0129] The passage 1520 may be a channel such as a microchannel, for example. Although not explicitly shown, the passage 1520 may have a specified width W and an area A, as desired, necessary, or required. Any of the aforementioned dimensions may increase above or below the microscale. Additionally, any of the passages may include various shapes and contours, as required, necessary, or desired. They may have various angles or pitches. The passage 1520 may be a channel such as a nanochannel, for example, but is not limited thereto.

[0130] In FIG. 18A, the general enlargement of the passage 1521 is achieved by arranging the microfeatures 1514 so as to define a radial passage 1520 for accommodating the vapor path 1521. In such an embodiment, the closely configured microfeatures 1514 near the center achieve the advantage of efficient heat transfer, and the close configuration does not impede the vapor flow because the amount of vapor accumulating within the portion of the passage 1520 near the center is relatively small. As the microfeatures 1514 extend away from each other in the direction of the path 1521, the passage 1520 enlarges to accommodate the accumulation of vapor along the length of the path 1521.

[0131] The embodiment shown in FIG. 18A is merely one of such examples. The enlargement of the passage 1520 along the vapor flow path 1521 can be accomplished through various embodiments. For example, the passage 1520 can be irregularly shaped, and the microfeatures 1514 that define the passage 1520 can be constructed to have intermittency, as opposed to a continuous positioning along the passage 1520 that accommodates the path 1521 along which the vapor will travel.

[0132] Referring now to FIG. 18B, in other embodiments of the present technology, the microfeatures 1514 may be constructed to form passages 1520 that are substantially parallel. In this type of arrangement, the passages 1520 do not enlarge in the direction in which the accumulating vapor travels. Instead, they maintain a substantially constant cross-sectional area along the length of the passages 1520.

[0133] FIG. 18C shows another embodiment of the present technology where the microfeature 1514 is positioned in a radial manner from the center point 1542. In certain such embodiments, the microfeature 1514 that defines the passageway 1520 is constructed to be intermittent as opposed to a continuous positioning along the passageway 1520 for accommodating the path 1521 of vapor flow. This may be accomplished, for example, by utilizing the microfeature 1514 formed in the form of pins, struts, rods, (or similar structures) or combinations thereof. This may also be accomplished, for example, by utilizing the microfeature 1514 formed in the form of a panel or wall of intermittent length as opposed to a panel or wall that extends the length of the evaporator portion of the device.

[0134] In the embodiment represented in FIG. 18C, the microfeature 1514 is installed in an intermittent radial manner such that the number of available passageways 1520 generally increases along the path 1521 through which the accumulating vapor progresses. In this way, the overall vapor space defined by the passageways 1520 can generally expand and increase along the irradiation path 1521 through which the accumulating vapor progresses. However, as shown, the width of the passageways remains substantially the same. However, as the path extends radially outward, the density of the extension members (e.g., rods or pins) may decrease such that the width of the passageways can increase.

[0135] FIG. 18D shows yet another embodiment that uses a radial positioning of the microfeature 1514 from the center point 1542. Similar to other embodiments, the embodiment represented by FIG. 18D generally forms the passageway 1520 that increases in size and / or number along the passageway 1520 to accommodate the path 1521 of vapor flow and thus the overall vapor space that can accommodate the accumulating vapor. For example, the extension members in the form of pins, struts, or rods (or similar structures) may be incorporated at a higher density towards the center of the device as compared to the outer or circumferential portion of the device.

[0136] Referring now to FIG. 18E, in some embodiments, segments of microfeatures 1514, which are also generally parallel to each other, may be used to define channels 1520 that are generally parallel to each other. In this embodiment, the number of microfeatures 1514 within any channel 1520 generally decreases in the direction of path 1521 along which the accumulating vapor travels. This may be accomplished, for example, by positioning some of the microfeatures 1514 near the center and extending them to different lengths such that some do not extend to the edge of the device, thus allowing the channels 1520 to widen and accommodate vapor accumulation in diverse and multiple paths 1521. In this way, the overall vapor space defined by the channels generally widens and increases in the direction of channels 1520 and the paths 1521 of vapor flow.

[0137] Referring now to FIGS. 19A - 19D, in some embodiments, one or more microfeatures 1514, formed in the form of walls or panels, may be used. In some embodiments, the walls or panels may be curved or contoured. Some shapes may include multiple contours (FIG. 19A), multiple angles (FIG. 19B), a single curve (FIG. 19C), and straight alignments (FIG. 19D). It should be understood that the different embodiments of microfeatures 1514 presented herein may be used in combination with each other or in combination with other forms. Additionally, the form of the microfeatures 1514 used in any embodiment may be uniform or substantially uniform. An example of a curved design may be reflected by a spiral pattern.

[0138] Figures 20A - 20E show additional forms of the microfeature 1514. These embodiments may be used to form one or more extension members in the form of rods, pins, or struts (or the like). The microfeature 1514 may have one or more of the following different cross - sections, namely, circular, oval, rectangular (or square), hexagonal, and triangular, and any combination thereof. In other words, the cross - section may be any polygonal cross - section or any conceivable geometric shape. For example, the extension member may be at least one of a triangle, a triangular prism, a pyramid, a cone, and a cylinder.

[0139] According to one aspect, the heat flux generated by the semiconductor device of the present technology is dissipated by the heat transfer unit. This heat flux can be approximated as follows. Along with the assumption that biological tissue is approximated as liquid water, the target to be cooled is a cube of tissue with dimensions of 1 cm wide × 1 cm long × 1 mm thick, and it is assumed that the contact cooling system reduces the temperature of the mass enclosed within the main volume from 35 °C to 5 °C. The thermal energy that must be extracted from the target to lower its temperature from its initial temperature T1 to the target temperature T2 is as follows. E = ρVC p (T1 - T2) Where ρ is the material density, V is the volume, and C p is the specific heat capacity. Regarding the case described above, the variables are as follows.

Chemical formula

Chemical formula

[0140] Heat flow Q C and heat flux q C can be calculated as follows.

Chemical formula

[0141] In the heat management system described herein, q C is the average heat flux into the cold side of a thermoelectric (Peltier) module. The heat flux out of the hot side of the thermoelectric module is determined by the characteristics of the thermoelectric module and the temperatures at the hot and cold sides of the thermoelectric module. For an exemplary thermoelectric module (potted version from TE Tech module TE - 65 - 0.6 - 0.8), and for hot and cold side temperatures of - 10 °C and - 20 °C respectively, the heat flows on the cold and hot sides of the module are as follows. Q C,TE = 8 W Q H,TE = 25 W

[0142] Q C,TE > Q C Therefore, the thermoelectric module can remove heat energy from the target quickly enough to meet the requirement of cooling the target from 35 °C to 5 °C within 2 seconds.

[0143] The heat flux q on the hot side of the Peltier module H,TE is as follows.

Chemical formula

[0144] The two-phase cooling system mounted on the high-temperature side of the thermoelectric Peltier module needs to remove heat at the rate defined above in order for the hybrid system to cool the target at the defined desired rate (a temperature drop of 30 °C within 2 seconds). The cooling system is designed to provide a high cooling capacity at a small temperature difference (less than 5 °C) between the heat source (Peltier module) and the working fluid.

Chem.

[0145] To remove this amount of thermal energy E H the mass of the working fluid that needs to be changed from liquid to vapor is as follows. m Ref = E H / h fg where h fg is the latent heat of vaporization for the working fluid. Using HFO-1234ze as the working fluid, it is as follows. h fg = 190 kJ / kg Therefore, the mass required for the working fluid to complete the cooling cycle is as follows. m Ref = 2.63×10 -4 kg The mass flow rate of evaporation is as follows.

Chem.

[0146] This is a large evaporation mass flow rate. The contact surface area between the liquid and the solid to induce liquid evaporation at this rate can be calculated using the equation described in U.S. Patent No. 10,217,692. A large contact surface area between the liquid and the solid requires many channels or a large contact surface area between the solid channels and the fluid packaged within a 1 cm × 1 cm area, imposing a large pressure drop on the liquid. The pressure gradient to induce such a flow rate is very large. An exemplary channel design useful in the present technology is a fractal topology that allows the fluid to flow through the phase change components of the system at a very low pressure gradient (or, in some cases, passively, i.e., self-driven flow). The cooling system described above has a compact footprint (less than 5 mm) and can be integrated into a wide range of energy-based tissue treatment systems and other applications. The entire system provides ultra-fast cooling and very high control capabilities within a very compact package, regardless of whether it is made of a transparent or non-transparent material.

[0147] Another aspect of the present technology is to monitor the temperature distribution within the target material at different depths or layers within the target material during energy-based treatment. For example, one aspect is to non-invasively monitor the temperature distribution inside the volume of mammalian tissue (e.g., human tissue) using electromagnetic / mechanical waves during energy-based therapy or treatment (e.g., laser therapy, radiation beam therapy, or cryogenic-based treatment such as reducing subcutaneous lipid tissue via cooling, ablating lesions (e.g., freezing lesions), etc.). During operation, the molecules of the tissue absorb, scatter, or re-emit the propagating waves, and the effect of the thermal energy exerted on the molecules changes the interaction between the waves and the tissue. These changes can be detected by measuring the changes in the return waves or other energy received by the detection transducer. This can provide online / real-time temperature monitoring with high accuracy and reliability. The non-invasive nature of this aspect of the present technology provides a robust tool for accurately monitoring different types of tissue, improving the safety and reliability of energy-based treatment and reducing the risk of damage to non-target treatment areas.

[0148] In some embodiments, mechanical waves (e.g., ultrasound) can be applied to tissue through an array of transducer elements (e.g., piezoelectric transducers). Referring to FIGS. 21A - 21C, a non-invasive monitoring system 2100 can include an array 2101 of transducers 2110 configured to transmit ultrasonic energy to a target material 101 and detect a return component of the ultrasonic energy. The transducers 2110 of system 2100 are arranged in a single row (FIG. 21B) or in several rows (FIG. 21C). FIGS. 22 and 23 show an alternative non-invasive monitoring system 2200 having a transducer array 2201 in which the transducers 2210 are separated by a gap G. These arrangements can be a single transducer instead of an array, or in the case of an array with multiple transducers, any number of transducers can be used (there are no limitations regarding the size or number of transducers).

[0149] The arrangements of transducers 2110 and 2210 shown in FIGS. 22A - 23 are linear, but in other embodiments, the transducer arrays 2101 and 2201 can be curved, 1.5D arrays, 2_D arrays, convex, concave, annular, inward-facing, diagonal, variable angle, double-linear, double 1.5D, or coaxial (annular). Scanning of the treatment area can be performed by sweeping the wave along a linear path or using a phased array transducer. The frequency of the wave transmitted depends on the depth and the desired resolution.

[0150] Referring to FIGS. 21A - 23, an array of transducers can produce a beam and monitor the thermal profile of the overall treatment area using different delayed phase waves. The elevation focus depth can vary from a depth of 0.5 mm within the tissue to 20 cm depending on the location of the area of interest.

[0151] Transducer arrays 2101 and 2201 can be located inside and / or outside of an applicator of an energy-based device. For example, clusters of transducers within the array can be located in different areas inside and / or outside of the applicator to contact tissue.

[0152] FIG. 24 shows a non-invasive monitoring system having a transducer array 2401 having transducers 2410a-b (collectively referred to as "transducer 2410") arranged on a curved energy device applicator 2420. The energy device applicator 2420 can be any of the contact members of the thermal management system described above with reference to FIGS. 1A-20E such as contact member 101. This is particularly useful in cryo-based applications where the contact member directly cools the epidermis, such as reducing subcutaneous lipid tissue for slimming, to treat subcutaneous tissue. The energy device applicator 2410 can alternatively be a component of a laser system or a radiation beam system that heats a target material. The non-invasive monitoring system can have a first transducer 2410a inside the applicator 2420 that contacts tissue and a second transducer 2410b outside the applicator 2420 that also contacts tissue. The thermal distribution inside the tissue changes over time and can be monitored constantly or on an as-needed basis. This can be done by turning the transducers on / off or activating them continuously throughout the procedure.

[0153] Other embodiments of non-invasive tissue monitoring use polarized electromagnetic (EM) waves with wavelengths up to 100,000 μm. As these waves travel through tissue, either transmission, reflection, absorption, refraction, diffraction, or scattering occurs. For example, during energy-based therapy, the applied energy changes the temperature of the tissue, which modifies its behavior / response to EM waves. Variations in the temperature of the tissue at various depths within the tissue can thus be monitored through the measurement of changes in the polarization, amplitude, wavelength, frequency, time-of-flight, phase shift, and intensity of the EM waves.

[0154] FIG. 25 shows a non-invasive monitoring system 2500 having at least one EM source 2510 and at least one EM detector 2520. In the illustrated embodiment, system 2500 has one EM source 2510 and three EM detectors 2520a-c (collectively referred to as "EM detector 2520"), although any number of EM sources 2510 and EM detectors 2520 can be used. The EM source 2510 and the EM detector 2520 can be mounted on an applicator 2550 such as any of the aforementioned thermal management systems described above with reference to FIGS. 1A-20E or the contact member of any laser / radiation type tissue treatment device. The distance between the source 2510 and the detector 2520 is a function of the depth of the target treatment area within the tissue, such as 0.5 mm to several centimeters. The arrangement of the source 2510 and the detector 2520 depends on the progress of the thermal profile of the cooling / heating treatment through the tissue. During operation, one or more EM waves are transmitted through the source 2510 to the target material 101 (e.g., mammalian tissue), and the backscattered energy is recorded by the detector 2520. In this embodiment, the EM travels to the detector 2520 through a banana-shaped path.

[0155] FIG. 26 illustrates another embodiment where several sources 2510 and several detectors 2520 are at different locations and distances from each other. The sources 2510 and detectors 2520 can produce / detect EM waves 2610 that are received directly from the source 2510 to the detector 2510, or the EM waves 2602 can be curved (e.g., banana-shaped) or otherwise non-linear. Arrows 2603 and 2604 indicate the polarization axes of the EM waves 2602. The sources 2510 and detectors 2520 can be placed at any location inside or outside the applicator on or around the treatment area. One aspect of this embodiment is useful in applications where the sources 2510 and detectors 2520 arranged perpendicular to the side surface are such that the tissue is not flat (either raised or sunken) and the treatment is applied along the top and / or side of the tissue. In this case, the EM waves 2601 can pass directly across the thermal profile direction. As a result, as the thermal profile penetrates deeper into the tissue, the lower detector 2520 of the detectors 2520 arranged vertically can measure the temperature gradient as a function of the depth within the tissue.

[0156] As the EM waves travel along a banana-shaped path, an increase in the distance between the source 2510 and the detector 2520 increases the depth within the target material that can be monitored. Placing several detectors at different distances from the source provides monitoring of different layers at different depths within a volume of tissue. In another embodiment, the EM waves traveling through the medium can be collected by a polarization detector or via a regular detector. The information collected via the regular detector can be further processed to detect the effect of temperature changes on polarizing the light.

[0157] FIG. 27 shows an embodiment of a non-invasive monitoring system 2500 with an array of a source 2510 and a detector 2520 on a curved applicator 2550. FIG. 28 shows another embodiment of the non-invasive monitoring system 2500 with a specific array of the source 2510 and the detector 2520. As shown in FIG. 28, the vertical source 2510 and the detector 2520 can transmit / detect the EM wave 2605 along the side surface of the target material 101. The source 2510 and the detector 2520 can be switched on / off or can be always activated. The detector can be paired with only one or several sources at a time.

[0158] During operation, the thermal and optical properties of the medium vary with temperature, which in turn affects the polarization angle or / and the direction of non-polarized / polarized EM waves. Through monitoring the change of the polarization angle or / and the direction of the polarized EM wave, the temperature distribution inside the tissue at different depths and locations can be determined. The pre-processing of the transmitted EM wave and the post-processing of the received EM wave, together with the appropriate hardware and source / detector array, enable the accurate real-time determination of the temperature gradient within a volume of tissue. As a result, the non-invasive monitoring system 2500 provides a robust tool for controlling heating and cooling therapies.

[0159] One use of the non-invasive monitoring system 2500 is to confine the freezing front within the lipid tissue. For example, based on the thickness of the lipid tissue, the cooling continues until the refractive, dissipative, absorptive, scattering coefficients, amplitude, flight time, and phase shift regarding the received signal become constant. Different wavelengths can also be used to separately monitor different components of tissues such as fat, water, and muscle. To prevent the freezing front from reaching the non-target area, the fluctuations in the signal received from the non-target area should remain invariant during the treatment. For example, using other calculation methods such as the least mean square calculation, or recursive least squares, adaptive filter, empirical mode decomposition, or blind signal source separation, the signal from the detector 2520 can be processed to determine the temperature gradient from the epidermal layer through the subcutaneous lipid tissue.

[0160] From the foregoing, it should be understood that, for purposes of illustration, specific embodiments of the present technology have been described herein, but that various modifications may be made without departing from the present disclosure. Thus, the present invention is not limited except as by the appended claims. Further, certain aspects of the new technology described in the context of a particular embodiment may also be combined or excluded in other embodiments. Additionally, the advantages associated with certain embodiments of the new technology are described in the context of those embodiments, but other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages in order to fall within the scope of the present technology. Thus, the present disclosure and the related technology can encompass other embodiments not explicitly illustrated or described herein.

Example

[0161] Those skilled in the art will appreciate, using the knowledge obtained from the present technology, that various combinations of embodiments and features from the embodiments are within the scope of the present technology. Examples of such combinations are listed in the following numbered appendices by way of non-limitation. (Example 1) A thermal management system comprising: a thermoelectric component having a first side configured to be thermally coupled to a target material and a second side opposite the first side; a two-phase heat transfer unit thermally coupled to the second side of the thermoelectric component, the two-phase heat transfer unit comprising: 1) a phase change chamber having an inlet region and an outlet region; 2) microfeatures within the phase change chamber spaced apart from each other to induce capillary forces that drive a working fluid from the inlet region of the phase change chamber to the outlet of the phase change chamber; 3) an inlet through which the working fluid flows into the two-phase heat transfer unit in a liquid phase; and 4) an outlet through which at least a portion of the working fluid flows out of the two-phase heat transfer unit in a gas phase. A controller configured to operate a thermoelectric component and a two-phase heat transfer unit such that the two-phase heat transfer unit cools a second side of the thermoelectric component to a first temperature, and the thermoelectric component changes the temperature of a target material to a second temperature within 0.5 to 20 seconds, wherein the second temperature is + / - 60 °C of the first temperature. A system comprising the same. (Example 2) The contact member, the thermoelectric component, and the two-phase heat transfer unit all have a height measured along the direction of heat flow from the contact member through the thermoelectric component of 2 mm to 25 mm, for the system according to Appendix 1. (Example 3) The controller is configured to set the two-phase heat transfer unit to a first temperature of 5 °C to -20 °C on a second side of the thermoelectric unit, and the controller is configured to operate the thermoelectric unit to heat the contact member to a second temperature of 20 °C to 40 °C within 1 to 10 seconds, for the system according to either Appendix 1 or 2. (Example 4) The two-phase heat transfer unit has a thickness measured in the direction of heat flow from the thermoelectric component of 3 mm to 8 mm, for the system according to any one of Appendices 1-3. (Example 5) The micro features are spaced 10 microns to 1,000 microns apart from each other, for the system according to any one of Appendices 1-4. (Example 6) The micro features are channels defined by walls extending from an inlet region to an outlet region of the phase change chamber, for the system according to Appendix 5. (Example 7) The micro features are pins within the phase change chamber, for the system according to Appendix 5. (Example 8) The micro features are spaced 10 microns to 250 microns apart from each other, for the system according to any one of Appendices 1-7. (Example 9) The thermoelectric component comprises a first Peltier module. The system further includes a second Peltier module positioned laterally to the first Peltier module. The phase transition chamber of the two-phase heat transfer unit includes a first phase transition chamber. The two-phase heat transfer unit further includes a second phase transition chamber positioned laterally to the first phase transition chamber. The first phase transition chamber is aligned with the first Peltier module, and the second phase transition chamber is aligned with the second Peltier module. The system according to any one of Appendices 1-8. (Example 10) The controller is configured to set the two-phase heat transfer unit to a first temperature of 5°C to -20°C on the second side of the thermoelectric unit. The controller is configured to operate the thermoelectric unit to heat the contact member to a second temperature of 10°C to 40°C within 1 to 10 seconds. The system according to Appendix 9. (Example 11) The two-phase heat transfer unit has a thickness measured from the thermoelectric component in the direction of heat flow of 2 mm to 8 mm. The system according to any one of Appendices 9 and 10. (Example 12) The micro features are spaced 10 microns to 1,000 microns apart from each other. The system according to any one of Appendices 9-11. (Example 13) The micro features are channels defined by walls extending from the inlet region to the outlet region of the phase transition chamber. The system according to Appendix 12. (Example 14) The micro features are pins within the phase transition chamber. The system according to Appendix 12. (Example 15) The micro features are spaced 10 microns to 250 microns apart from each other. The system according to any one of Appendices 9-14. (Example 16) The thermoelectric component has a first volumetric heat capacity, and the two-phase heat transfer unit has a second volumetric heat capacity such that the second volumetric heat capacity does not exceed one of 50%, 100%, 150%, 200%, 250%, 300%, 400%, or 500% of the first volumetric heat capacity, the system according to any of Appendices 9-15. (Example 17) The system further includes a condenser fluidly coupled to the inlet and outlet of the two-phase heat transfer unit, and the working fluid is contained within the condenser and the two-phase heat transfer unit, the system according to any of Appendices 9-16. (Example 18) A method for thermally managing a target material, positioning a first side of a thermoelectric component to be thermally coupled to the target material; using a two-phase heat transfer unit thermally coupled to a second side of the thermoelectric component to cool the second side of the thermoelectric component to a first temperature; adjusting an electric current through the thermoelectric component such that the target material reaches a second temperature within 0.5 to 20 seconds, the second temperature being + / - 60 °C of the first temperature; a method including. (Example 19) Both the thermoelectric component and the two-phase heat transfer unit have a height measured along the direction of heat flow through the thermoelectric component of 5 mm to 25 mm, the method according to Appendix 18. (Example 20) The first temperature is 5 °C to -20 °C on the second side of the thermoelectric unit, the second temperature is 20 °C to 40 °C, and the time from the first temperature to the second temperature is 1 to 10 seconds, the method according to any of Appendices 18 and 19. (Example 21) The two-phase heat transfer unit has a thickness measured from the thermoelectric component in the direction of heat flow of 3 mm to 8 mm, the system or method according to any of Appendices 18-20. (Example 22) The microfeatures are a system or method according to any of Appendices 18 - 21, spaced 10 microns to 1,000 microns apart from each other. (Example 23) The microfeatures are a channel defined by a wall extending from an inlet region to an outlet region of a phase transition chamber, a system or method according to any of Appendices 18 - 22. (Example 24) The microfeatures are pins within a phase transition chamber, a system or method according to any of Appendices 18 - 22. (Example 25) A non - invasive monitoring system having a source for transmitting energy to a target material, and a detector for detecting components of the energy transmitted to the target material by the source, wherein the temperature gradient within the target material is determined by information from the detector, a system or method according to any of Appendices 1 - 24. (Example 26) The source is a light source and the detector is a photodetector, a system or method according to any of Appendices 1 - 26. (Example 27) A device for treating human tissue, A tissue heating module configured to heat a target tissue to a therapy temperature, (a) A contact plate having high thermal conductivity, (b) A thermoelectric component having a first side configured to be thermally coupled to the contact plate and a second side opposite the first side, (c) A two - phase heat transfer unit thermally coupled to the second side of the thermoelectric component, the two - phase heat transfer unit having: 1) a phase transition chamber having an inlet region and an outlet region; 2) microfeatures within the phase transition chamber spaced apart from each other so as to induce capillary forces that drive a working fluid from the inlet region of the phase transition chamber to the outlet of the phase transition chamber; 3) an inlet through which the working fluid flows into the two - phase heat transfer unit in the liquid phase; and 4) an outlet through which at least a portion of the working fluid flows out of the two - phase heat transfer unit in the gas phase. (d) A controller configured to operate the thermoelectric component and the two-phase heat transfer unit such that the two-phase heat transfer unit cools the second side of the thermoelectric component to the first temperature, and the thermoelectric component changes the temperature of the contact plate to the second temperature within 0.5 to 20 seconds, wherein the second temperature is + / - 60 °C of the first temperature, and a controller; A thermal management system including; A device comprising. (Example 28) The device according to appendix 27, wherein the tissue heating module comprises a laser configured to heat the target tissue to a therapeutic temperature, while the contact plate cools the adjacent tissue. (Example 29) The device according to any one of appendices 27 and 28, further comprising a non-invasive monitoring system having a source for transmitting energy to a target material and a detector for detecting a component of the energy transmitted to the target material by the source, wherein the temperature gradient within the target material is determined by information from the detector. (Example 30) The device according to appendix 29, wherein the source is a light source and the detector is a photodetector. (Example 31) A device for cooling a person's tissue, A contact plate having high thermal conductivity, A thermoelectric component having a first side and a second side opposite the first side, configured to be thermally coupled to the contact plate, A two-phase heat transfer unit thermally coupled to the second side of the thermoelectric component, the two-phase heat transfer unit comprising: 1) a phase change chamber having an inlet region and an outlet region; 2) micro-features within the phase change chamber spaced apart from each other to induce capillary forces that drive the working fluid from the inlet region of the phase change chamber to the outlet of the phase change chamber; 3) an inlet through which the working fluid flows into the two-phase heat transfer unit in the liquid phase; and 4) an outlet through which at least a portion of the working fluid flows out of the two-phase heat transfer unit in the gas phase. A controller configured to operate a thermoelectric component and a two-phase heat transfer unit such that the two-phase heat transfer unit cools a second side of the thermoelectric component to a first temperature and the thermoelectric component changes the temperature of a contact plate to a second temperature within 0.5 to 20 seconds, wherein the second temperature is + / - 60 °C of the first temperature, A device comprising. (Example 32) The device according to appendix 31, further comprising a non-invasive monitoring system having a source for transmitting energy to a target material and a detector for detecting a component of the energy transmitted to the target material by the source, wherein the temperature gradient within the target material is determined by information from the detector. (Example 33) The device according to appendix 32, wherein the source is a light source and the detector is a photodetector. (Example 34) A semiconductor device, A semiconductor component having an integrated circuit network, (a) A thermoelectric component having a first side configured to be thermally coupled to the semiconductor component and a second side opposite the first side, (b) A two-phase heat transfer unit thermally coupled to the second side of the thermoelectric component, the two-phase heat transfer unit comprising: 1) a phase change chamber having an inlet region and an outlet region; 2) microfeatures within the phase change chamber that are spaced apart from each other to induce capillary forces that drive a working fluid from the inlet region of the phase change chamber to the outlet of the phase change chamber; 3) an inlet through which the working fluid flows into the two-phase heat transfer unit in a liquid phase; and 4) an outlet through which at least a portion of the working fluid flows out of the two-phase heat transfer unit in a gas phase, (c) A controller configured to operate the thermoelectric component and the two-phase heat transfer unit such that the two-phase heat transfer unit cools the second side of the thermoelectric component to a first temperature and the thermoelectric component changes the temperature of the semiconductor component to a second temperature, A thermal management system including. A semiconductor device comprising. (Example 35) The semiconductor component is the semiconductor device described in Appendix 34, which is a controller. (Example 36) The semiconductor component is the semiconductor device described in Appendix 34, which is a memory device. (Example 37) The semiconductor component is the semiconductor device described in Appendix 34, which is within a server. (Example 38) A method for modifying the temperature of a patient's tissue, comprising: (a) At a first temperature T1, thermally contacting a device comprising a thermoelectric component to the outer surface of a first tissue target, wherein a heat transfer unit is thermally in contact with the thermoelectric component; (b) Activating a current through the thermoelectric component in a first direction to cause cooling of the outer surface of the first tissue target from the first temperature T1 to about 8°C to about -15°C within about 2 to 4 seconds, wherein the heat transfer unit removes the heat flux generated by the thermoelectric component and maintains the thermoelectric component at an operating temperature below at least 50°C; (c) Activating a current through the thermoelectric component in a second direction opposite to the first direction to cause heating of the outer surface of the first tissue target from about 8°C to about -15°C to at least about 20°C within about 1 to 3 seconds. A method comprising the above steps. (Example 39) The method according to Appendix 38, wherein the first tissue target is irradiated with a laser beam or punctured with a needle after step (b) and before step (c). (Example 40) The method according to Appendix 38, wherein the first tissue target is irradiated with a laser beam while the device remains in contact with the first tissue target after step (b) and before step (c). (Example 41) The method according to Appendix 38, wherein the first tissue target is punctured with a needle while the device remains in contact with the first tissue target after step (b) and before step (c). (Example 42) The heat transfer unit is the method according to appendix 38, which is a two-phase evaporative heat transfer device. (Example 43) The heat transfer unit is the method according to appendix 38, which is a two-phase evaporative heat transfer device including an evaporation system having a plurality of walls extending downward from a base into a reservoir of an evaporative fluid. (Example 44) The heat transfer unit is the method according to appendix 38, which is a two-phase evaporative heat transfer device having a condenser unit operably connected thereto, receiving vapor from the two-phase evaporative heat transfer device, and condensing the vapor into the evaporative fluid. (Example 45) The heat transfer unit is the method according to appendix 38, which is a two-phase thermo-evaporative heat transfer device connected to an inflow and an outflow conduit for the passage of the evaporative fluid therethrough. (Example 46) In step (b), the step of activating the current in a first direction through the thermoelectric component causes cooling of the outer surface of the first tissue target from a first temperature T1 to about 8°C to about -2°C within about 3 seconds, according to the method described in appendix 38. (Example 47) In step (b), the step of activating the current in a first direction through the thermoelectric component causes cooling of the outer surface of the first tissue target from a first temperature T1 to about 4°C to about -2°C within about 2 to 4 seconds, according to the method described in appendix 38. (Example 48) In step (b), the step of activating the current in a first direction through the thermoelectric component causes cooling of the outer surface of the first tissue target from a first temperature T1 to about 4°C to about -2°C within about 3 seconds, according to the method described in appendix 38. (Example 49) In step (c), the step of activating the current in a second direction opposite to the first direction through the thermoelectric component causes heating of the outer surface of the first tissue target from about 8°C to about -2°C to at least about 20°C within about 2 seconds, according to the method described in appendix 38. (Example 50) The device includes a transparent material, and the laser light is transmitted through the transparent material to the surface of the first tissue target to treat the first tissue target, as described in Appendix 38. (Example 51) The device includes one or more channels through which the laser light is transmitted to the surface of the first tissue target to treat the first tissue target, as described in Appendix 38. (Example 52) The device includes one or more channels through which one or more needles are carried to pierce the surface of the first tissue target to treat the first tissue target, as described in Appendix 38. (Example 53) The device is attached to a hand-held laser emitting device in a manner that receives laser light from the hand-held laser emitting device, as described in Appendix 38. (Example 54) The method further includes thermally contacting the device with the outer surface of the second tissue target and repeating steps (a)-(c), as described in Appendix 38. (Example 55) The method further includes continuously repeating steps (a)-(c) on a plurality of target tissues, as described in Appendix 38. (Example 56) The device includes a plurality of thermoelectric components that are electrically connected in series and thermally connected in parallel, as described in Appendix 38. (Example 57) The device includes a plurality of thermoelectric components that are electrically connected in series and thermally connected in parallel, and each thermoelectric component has an associated microchannel evaporation structure positioned adjacent thereto to remove heat from the thermoelectric component, as described in Appendix 38. (Example 58) The thermoelectric components are electrically connected to a programmable power source, as described in Appendix 38. (Example 59) The device includes a plurality of thermoelectric components that are electrically connected in series and thermally connected in parallel, and the plurality of thermoelectric components are electrically connected to a programmable power source, as described in Appendix 38.

Claims

[Claim 1] The invention as depicted in the drawings of this application.

Images