Carbon nanotube vs. metal assembly

Abstract

This disclosure provides carbon nanotube (CNT)-to-metal assemblies, including carbon nanotube (CNT) members connected to metal members, and methods for preparing them. The assemblies may be connected via CNT-to-metal connectors, which may include CNT connector pads.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority to U.S. Provisional Patent Application No. 63 / 462926, filed on 28 April 2023, which is incorporated herein by reference in its entirety.

[0002] This specification describes carbon nanotube (CNT)-to-metal assemblies, including carbon nanotube (CNT) members connected to a metal member, and methods for preparing them. The CNT members may be connected to the metal member via a CNT-to-metal connector, which may optionally include a CNT connector pad. [Background technology]

[0003] Carbon nanotube (CNT) materials, such as fibers, films, and coatings, have been developed to possess properties, including conductivity, that enable their use in a wide range of applications. CNTs have primarily been used as additives to improve the properties of other materials, such as polymers, metals, and ceramics. However, with the emergence of pure CNT conductors, the challenge arises of connecting these carbon-based conductors with conventional metal-based electronics.

[0004] The challenges associated with connecting CNT components (e.g., components containing CNT material) to metal components are multifaceted and stem from factors such as (1) the poor wettability of commonly used soldering and brazing methods to carbon materials, (2) inappropriate composition, structure, and properties of the CNT material, (3) differences in properties between the CNT material and the metal component at the interface, and (4) difficult applications (e.g., those involving chemically harsh environments and / or mechanical / thermal cycling). For example, the poor wettability of carbon allotropes by liquid metal at typical soldering temperatures is a well-known problem, with typical contact angles far exceeding 90 degrees. This may be due to the absence of chemical bonding at the carbon / metal interface, with only weak van der Waals forces providing a physical bonding mechanism. On the other hand, good wettability of liquid metal on a solid substrate is observed when the interfacial bonding is strong (e.g., chemical properties), as shown in the Young-Dupre equation. Generally, when liquid metal solder is applied to a solid metal surface, the interfacial bond is metallic, and therefore, regardless of the miscibility between the liquid and solid, good wettability (e.g., a contact angle of 1-20 degrees) can be achieved. In some situations, metals (e.g., Al, Ti, Zr, Cr, W, or Mo) can react with carbon to form carbide species with stronger interfacial bonds. However, such compounds (e.g., carbides) are usually far less conductive than pure metals, and typically, this comes at the cost of increased contact resistance. A known example is the reaction between aluminum and carbon, which forms aluminum carbide (Al4C3). This carbide layer causes a significant increase in the electrical resistance of devices that rely on current transport across such interfaces, and consequently, a decrease in efficiency.

[0005] Regarding CNT materials, including CNT components, their high surface area, combined with large contact angles, can lead to the formation of partially solid-liquid and partially solid-gas interfaces, resulting in the inclusion of void spaces. These voids can reduce the contact area, worsen contact resistance, and cause the solidified metal to delaminate from the CNT substrate (e.g., the CNT material). Other causes of voids may include improper processing and alignment of individual CNTs within the material, as well as the presence of impurities remaining from the CNT synthesis process, such as non-sp2 hybridized carbon and metal catalyst nanoparticles. Voids and improper alignment in CNT materials can result in lower conductivity, degrading the performance of connector assemblies. Since alignment promotes hexagonal close-packed arrangement of carbon nanotubes, improper alignment can also lead to increased voids. In certain applications, voids can result in parasitic capacitance, which is detrimental to the circuit and must be corrected or compensated for, thus increasing the cost and complexity of the system. Additionally, the presence of metallic particle impurities (e.g., residual metallic particle impurities from the CNT synthesis process) can negatively affect connector performance in other ways. For example, ferromagnetic particles such as iron are common catalysts in CNT synthesis, but their presence is highly problematic and can manifest as passive intermodulation (PIM) distortion in transmitted AC signals.

[0006] Furthermore, CNTs and metals possess specific and different material properties, which can also lead to a decrease in the performance of CNT-to-metal connectors, especially in challenging use cases (e.g., those involving chemically harsh environments and / or mechanical / thermal cycling). Typically, electrical systems are designed to protect connection points, for example, by utilizing strain relief, and / or by positioning the connection point away from the flex zone, and / or through proper insulation and thermal management. However, in applications involving significant mechanical and / or thermal loads, spatial design constraints may require the connection to withstand a certain degree of mechanical and / or thermal load. Applications involving periodic loads are particularly challenging. Different bending properties can cause deformation of the more flexible and softer CNT material under repeated bending contact with a more rigid and hard metal. Additionally, the differing thermal expansion properties (which are known to be positive for metals and negligible for CNTs) can lead to thermally induced stresses, which, when the metal-CNT interface undergoes repeated, non-uniform deformation, reduce the contact area and consequently increase contact resistance.

[0007] As mentioned above, these issues negatively impact the performance of CNT-to-metal connectors. For example, in constant current applications, this can lead to increased power loss in the connector, mechanical failure of the connector, and / or thermal damage to surrounding materials, all of which can ultimately lead to device failure. In AC applications, especially where high-fidelity signal transmission is required, further performance degradation is also a problem, in the form of increased signal attenuation due to PIM distortion and / or a decrease in the signal-to-noise ratio (SNR).

[0008] Therefore, carbon nanotube (CNT) pair metal assemblies, including carbon nanotube (CNT) members connected to metal members, and methods for preparing them are still needed. [Overview of the project]

[0009] This specification describes carbon nanotube (CNT)-to-metal assemblies, which include carbon nanotube (CNT) members connected to metal members, and methods for preparing them. The assemblies may be connected via CNT-to-metal connectors, which may include CNT connector pads.

[0010] In one embodiment, an assembly comprising a carbon nanotube (CNT) member connected to a metal member is provided herein, wherein the CNT member comprises a CNT material comprising at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), and the CNT or CNT material exhibits one or more or all of the following properties: (a) the CNT material has an electrical conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m; (b) the CNT has an average aspect ratio of at least 1,000, at least 5,000, or at least 10,000; and (c) the CNT has an average G / D ratio of at least 1, at least 10, or at least 100.

[0011] In some embodiments, the CNT members may be connected to metal members via CNT-to-metal connectors, the CNT-to-metal connectors comprising materials selected from graphene, metal, and metal-containing epoxy.

[0012] In some embodiments, the CNT member may be connected to a metal member via a CNT connector pad, the CNT connector pad comprising a CNT material containing at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), the CNT or CNT material exhibiting one or more of the following properties: (a) the CNT material has conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m; (b) the CNT has an average aspect ratio of at least 1,000, at least 5,000, or at least 10,000; and (c) the CNT has an average G / D ratio of at least 1, at least 10, or at least 100. The CNT connector pad may be connected to a metal member via a CNT-to-metal connector, the CNT-to-metal connector comprising a material selected from graphene, metal, and metal-containing epoxy. The CNT connector pad may consist of a single layer of aligned or unaligned CNT material, which may have a thickness of 1 to 10 μm. A CNT connector pad may consist of multiple layers of aligned CNT material and may have a thickness of 1 μm to 0.5 mm. The CNT connector pad may consist of multiple layers of aligned CNT material, the multiple layers including a first layer of the CNT material and a second layer of the CNT material, and optionally the first and second layers are arranged in different orientations relative to each other. The CNT connector pad may consist of multiple layers of aligned CNT material, the multiple layers including an outer layer of the CNT material and one or more intermediate layers of the CNT material, optionally one or more of the intermediate layers being sputter-coated or electroplated with a thin metal layer, optionally one or more of which are selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W, and optionally the metal being selected from Cu, In, or Ni.

[0013] According to any embodiment, the CNT material of the CNT member has the following characteristics: (i) the CNT material contains less than 20% by weight, less than 10% by weight, or less than 5% by weight of non-sp2 hybridized carbon material, or the non-sp2 hybridized carbon material is not present in the CNT material; (ii) the CNT material contains less than 10% by weight, less than 5% by weight, or less than 2% by weight of metallic particle impurities, or the metallic particle impurities are not present in the CNT material; and (iii) the CNT material contains at least 1 g / cm³ 3 at least 1.2 g / cm³ 3 , or at least 1.4 g / cm³ 3 It may further indicate that it has a density of, one or more of the following:

[0014] According to any embodiment, the CNT material of the CNT connector pad has the following characteristics: (i) the CNT material contains less than 20% by weight, less than 10% by weight, or less than 5% by weight of non-sp2 hybridized carbon material, or the non-sp2 hybridized carbon material is not present in the CNT material; (ii) the CNT material contains less than 10% by weight, less than 5% by weight, or less than 2% by weight of metallic particle impurities, or the metallic particle impurities are not present in the CNT material; and (iii) the CNT material has a concentration of at least 1 g / cm³ 3 at least 1.2 g / cm³ 3 , or at least 1.4 g / cm³ 3 It may further indicate that it has a density of, one or more of the following:

[0015] According to any embodiment, the CNT member of the CNT-to-metal assembly described herein may be in a form selected from films, fibers, foams, and coatings.

[0016] In any embodiment, the metal components of the CNT-to-metal assembly described herein may be selected from metal matrices, metal wires, metal cables, ring terminals, circuit board terminals, quick disconnect terminals, spade terminals, hook terminals, snap plug terminals, battery terminals, battery terminal clamps, battery springs, grounding blocks, butt splices, wire ferrules, terminal blocks, compression lugs, set screw lugs, BNC (Bayonet Neill-Concelman) connectors, TNC (Threaded Neill-Concelman) connectors, RCA (Radio Corporation of America) connectors, SMA (SubMiniature version A) connectors, SMC (SubMiniature version C) connectors, FFC (Flat Flexible Cable) connectors, FPC (Flexible Printed Circuit) connectors, DIN (Deutsches Institut fur Normung) connectors, and F-type connectors.

[0017] According to any embodiment, the CNT members of the CNT-to-metal assembly described herein may be selected from display electrodes, touchscreen electrodes, energy harvesting electrodes, solar cell electrodes, battery electrodes, electrostatic dissipation elements, grounding elements, resistive heating elements, strain detection elements, chemical sensor elements, antenna radiating elements, antenna grounding surfaces, coaxial cable outer shields, coaxial cable inner conductors, smart sheathing for on-site wear monitoring, resistive elements for sensors, capacitive elements for sensors, inductive elements for sensors, biosensing elements for muscle activity, biosensing elements for nerve activity, muscle stimulation electrodes, nerve stimulation electrodes, DC power cables, DC transmission lines, AC power cables, AC transmission lines, field emitters, transformer coils, DC motor coils, electronic textiles, resistors, transistors, conductors, capacitors, and inductors.

[0018] According to any embodiment, the CNT-to-metal assembly described herein may exhibit one or more of the following characteristics: signal attenuation of 20 dB to 30 dB, 10 dB to 20 dB, or 5 dB to 10 dB; a signal-to-noise ratio of 2:1 to 5:1, 5:1 to 20:1, or 20:1 to 100:1; a phase shift of the signal entering the assembly less than pi / 12 rad, less than pi / 24 rad, or less than pi / 96 rad; and a temperature difference compared to the steady-state temperature of the metal component less than 25 °C, less than 15 °C, or less than 5 °C.

[0019] In another embodiment, a method for producing an assembly according to any of the embodiments described above (e.g., a CNT-to-metal assembly) is provided herein, which includes bringing a CNT member and a metal member into contact at an interface to form a joint, and further includes one or more of the following steps: wrapping or tying the joint with CNT fibers or a film or foam; electroplating the surface of the CNT material of the CNT member with metal; sputter coating the surface of the CNT material of the CNT member with metal; wetting the surface of the CNT material of the CNT member before a soldering or brazing step; soldering or brazing the CNT material of the CNT member to the metal member; providing a conductive metal-filled epoxy at the interface; applying a reactive foil containing metal solder to the interface using one or more selected from pressure, electric current and heat; and potting, heat-shrinking or molding the assembly. The metal may be one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W, and optionally, the metal may be selected from Cu, In, or Ni.

[0020] In some embodiments, a method of fabricating an assembly (e.g., a CNT-to-metal assembly) according to any of the foregoing embodiments may include bringing a CNT member and a CNT-to-metal connector into contact at an interface to form a joint, and may further include one or more or all of the following steps: wrapping or tying the joint with a CNT fiber or film or foam; electroplating the surface of the CNT material of the CNT member with a metal; sputter coating the surface of the CNT material of the CNT member with a metal; wetting the surface of the CNT material of the CNT member prior to a soldering or brazing step; soldering or brazing the CNT material of the CNT member to the CNT-to-metal connector; providing a conductive metal-filled epoxy at the interface; applying a reactive foil containing a metal solder to the interface using one or more selected from pressure, current, and heat; and potting, heat shrinking, or molding the assembly. The metal may be one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W, and optionally, the metal is selected from Cu, In, or Ni.

[0021] In some embodiments, a method of fabricating an assembly (e.g., a CNT-to-metal assembly) according to any of the foregoing embodiments may include bringing a CNT member and a CNT connector pad into contact at an interface, and may further include one or more or all of the following steps: evaporating a solvent at the interface to connect the CNT member to the CNT connector pad via capillary action, optionally where the solvent is one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether); solvent welding the CNT connector pad to the CNT member using an acid; and mechanically joining the CNT connector pad to the CNT member.

[0022] In some embodiments, the method may further include bringing the CNT connector pad and the metal member into contact at an interface to form a joint of the assembly, and the following steps: wrapping or binding the joint with a CNT fiber or film or foam, electroplating the surface of the CNT material of the CNT connector pad with a metal, sputter coating the surface of the CNT material of the CNT connector pad with a metal, wetting the surface of the CNT material of the CNT connector pad prior to the soldering or brazing step, soldering or brazing the CNT material of the CNT connector pad to the metal member, providing a conductive metal-filled epoxy at the interface, applying a reactive foil containing a metal solder to the interface using one or more selected from pressure, current, and heat, and potting, heat shrinking, or molding the assembly. The metal may be one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W, and optionally, the metal is selected from Cu, In, or Ni.

[0023] In some embodiments, a method of making an assembly (e.g., a CNT-to-metal assembly) according to any of the foregoing embodiments may include providing a CNT connector pad on the surface of a metal member by wrapping or binding a pre-formed CNT film or foam around the metal member, wrapping or binding CNT fibers around the metal member, or forming a CNT film directly on the surface of the metal member from a fluid phase.

[0024] In some embodiments, a method for producing an assembly according to any of the embodiments described above (e.g., a CNT-to-metal assembly) may include transferring a CNT film or CNT foam from a transfer sleeve to a metal member, optionally including one or more or all of the following steps: wetting the surface of the metal member; inserting the metal member into a transfer sleeve loaded with the CNT film or CNT foam; compressing the transfer sleeve over / around the metal member; and withdrawing the transfer sleeve from the metal member to obtain a metal member with a CNT connector pad made of the CNT film or CNT foam. In some embodiments, the method further includes loading a pre-formed CNT film or CNT foam into a transfer sleeve. In some embodiments, loading includes one or more of the following steps: providing the CNT film or CNT foam around a support; wetting the inner surface of the transfer sleeve; inserting the support into the sleeve; compressing the sleeve over / around the support; and withdrawing the support from the sleeve to obtain a sleeve loaded with the CNT film or CNT foam. In other embodiments, loading includes one or more of the following steps: preparing a CNT film or CNT foam in situ on the inside of a transfer sleeve by forming a CNT film or CNT foam directly on the inner surface of the transfer sleeve from the fluid phase.

[0025] In some embodiments, the method may further include the following steps: promoting densification between the CNT connector pad and the metal member by evaporating a solvent at the interface between the CNT connector pad and the metal member to promote densification via capillary action, wherein optionally the solvent is one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether); promoting; applying pressure to the interface; applying electric current to the interface; and applying heat to the interface.

[0026] In some embodiments, the method may further include bringing a CNT member and a CNT connector pad into contact at an interface, and promoting densification between the CNT member and the CNT connector pad by one or more of the following steps: evaporating a solvent at the interface between the CNT connector pad and the CNT member to promote densification via capillary action, wherein optionally the solvent is one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether); solvent welding the CNT connector pad to the CNT member using an acid; and mechanically joining the CNT connector pad to the CNT member.

[0027] Furthermore, assemblies comprising carbon nanotube (CNT) members connected to CNT connector pads are provided herein, each of the CNT members and CNT connector pads independently comprising a CNT material comprising at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), wherein the CNTs or CNT material exhibit one or more or all of the following properties: the CNT material has a conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m; the CNTs have an average aspect ratio of at least 1,000, at least 5,000, or at least 10,000; and the CNTs have an average G / D ratio of at least 1, at least 10, or at least 100.

[0028] Furthermore, assemblies including metal members connected to CNT connector pads are provided herein, the CNT connector pads comprising a CNT material comprising at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), wherein the CNTs or CNT material exhibit one or more or all of the following properties: the CNT material has conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m; the CNTs have an average aspect ratio of at least 1,000, at least 5,000, or at least 10,000; and the CNTs have an average G / D ratio of at least 1, at least 10, or at least 100.

[0029] According to any embodiment, the metal member may include one or more metals selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W. [Brief explanation of the drawing]

[0030] [Figure 1]This provides digital photographs of mask electroplating of different metals onto a CNT film. Images a and b demonstrate that different metals can be electroplated onto a CNT film while their shapes are well controlled through masking. Image a shows Cu electroplated onto a CNT film in various shapes commonly used for soldering pads. Image b shows Cu, In, Zn, and Ni electroplated onto a CNT film in various shapes. Image c is a polarized optical microscope image of the electroplated CNT interface and the bare CNT interface, demonstrating that their fibrous microstructure and high surface area are preserved during the electroplating process on the CNT film. While not constrained by theory, given the irregular surface topology, it is generally believed that metals do not wet CNTs very easily. The absence of metal droplet formation indicates good coverage of the CNT structure during the electroplating process. [Figure 2] This provides digital images of carbon nanotube (CNT) fibers electroplated with Ni. It demonstrates that despite the high curvature of the thin CNT fibers (<100 μm) surface, their high conductivity and surface area are sufficient to enable solution electroplating with Ni. [Figure 3A] This demonstrates that electroplated Cu connector pads can help provide a surface that is easily wetted by common lead-free Sn solder. Figure 3A provides a digital photograph of an electroplated copper pad with wetted solder connected to a 10Ω resistor leg. Figure 3B shows laser and optical microscope images of Sn solder droplets on an electroplated Cu connector pad on a CNT film. Figure 3C provides a 3D laser surface profile of a Sn solder droplet showing a reference endpoint. [Figure 3B]This demonstrates that electroplated Cu connector pads can help provide a surface that is easily wetted by common lead-free Sn solder. Figure 3A provides a digital photograph of an electroplated copper pad with wetted solder connected to a 10Ω resistor leg. Figure 3B shows laser and optical microscope images of Sn solder droplets on an electroplated Cu connector pad on a CNT film. Figure 3C provides a 3D laser surface profile of a Sn solder droplet showing a reference endpoint. [Figure 3C] This demonstrates that electroplated Cu connector pads can help provide a surface that is easily wetted by common lead-free Sn solder. Figure 3A provides a digital photograph of an electroplated copper pad with wetted solder connected to a 10Ω resistor leg. Figure 3B shows laser and optical microscope images of Sn solder droplets on an electroplated Cu connector pad on a CNT film. Figure 3C provides a 3D laser surface profile of a Sn solder droplet showing a reference endpoint. [Figure 3D] This provides a 2D line profile used for exemplary measurement of the contact angle between a Sn solder droplet and a connector pad. This provides a direct measurement of an excellent wet contact angle (<45 degrees) between the solder droplet and the electroplated Cu connector pad, where the contact angle is parallel to the underlying CNT film. [Figure 3E] This provides a digital photograph of an exemplary CNT trace for AC signal transmission on a PCB (printed circuit board). The size of the Cu connector pad is approximately 1 mm in diameter when constant-current electroplating is used (substantially finer control can be achieved by using other methods such as pulsed and reverse-pulsed electroplating). Although not bound by theory, in AC signal transmission applications, the presence of ferromagnetic compounds such as Fe is thought to introduce distortion to the signal, such as passive intermodulation (PIM). Therefore, advantageously, the metal content in the CNT film (usually due to residual metal catalyst particles) is negligibly small in such applications. [Figure 4A]This demonstrates that electroplated CNT fibers can be easily wetted by common solder (e.g., solder rings found in solder-filled heat shrink tubing). Figure 4A provides a digital photograph of Ni-electroplated CNT fibers soldered to braided tinned copper wire. Figure 4B provides a digital photograph of Ni-electroplated CNT fibers connected to the legs of a 10Ω resistor via solder-filled heat shrink tubing. Circles are provided to show that portions of the electroplated fibers are wetted by solder. Upon reaching the operating temperature, the solder wets the fibers and flows along the electroplated fibers, forming a low contact angle at the interface. [Figure 4B] This demonstrates that electroplated CNT fibers can be easily wetted by common solder (e.g., solder rings found in solder-filled heat shrink tubing). Figure 4A provides a digital photograph of Ni-electroplated CNT fibers soldered to braided tinned copper wire. Figure 4B provides a digital photograph of Ni-electroplated CNT fibers connected to the legs of a 10Ω resistor via solder-filled heat shrink tubing. Circles are provided to show that portions of the electroplated fibers are wetted by solder. Upon reaching the operating temperature, the solder wets the fibers and flows along the electroplated fibers, forming a low contact angle at the interface. [Figure 5]This disclosure illustrates exemplary methods for ensuring good electrical contact between a metal wire / connector and a CNT material (e.g., CNT film and fiber). Image a provides a photograph of the CNT connector pad disclosed herein in the form of a CNT film wrapped around the exposed end of a metal wire. Image b shows the corresponding exposed end of the metal wire wrapped with CNTs in Image a. Images a and b demonstrate that a metal surface can be wrapped with a CNT film (solid) and that coating a metal surface with CNTs in a fluid phase can be achieved to form the CNT connector pad disclosed herein in the form of a CNT film formed on a metal surface. Image c shows an end-launch male SMA (SubMiniature Version A) connector wrapped with the CNT connector pad disclosed herein in the form of a CNT film, used as an interface between a (metal) coaxial cable and a CNT thin-film patch antenna ("CNT Member"). A network analyzer displays the S11 value as a function of frequency, with a minimum value of -18.8 dB at resonance. This indicates that when the center pin and ground foot of an SMA connector are wrapped in a CNT film and mechanically fixed to the feed point and ground surface of a CNT patch antenna, respectively, the resulting connector loss is negligibly low, and more than 99.99% of the EM energy is transmitted to the antenna, as indicated by the minimum S11 value at resonance. Although not bound by theory, it is thought that the mechanical properties of the CNT film allow for mechanical compression without damage. High conductivity and a large surface area allow for minimizing losses at the interface. Additionally, in RF applications, the presence of ferromagnetic compounds (e.g., Fe) may introduce additional loss mechanisms; therefore, the metal content in the CNT film (usually due to residual metal catalyst particles) needs to be negligibly low. [Figure 6A]This document provides exemplary approaches for forming CNT-to-metal assemblies, which can be used individually or in combination. CNT-to-metal assemblies can be prepared by directly bonding CNT material to a metal member, by preparing the surface of the CNT material using CNT connector pads disclosed herein, by preparing the surface of the metal member using CNT material, or by any combination of the aforementioned methods disclosed herein. Figure 6A provides a block diagram illustrating an exemplary method for forming a connected CNT-to-metal assembly using CNT connector pads. Figure 6B provides a block diagram illustrating an exemplary method for forming a connected CNT-to-metal assembly by preparing the surface of a metal member using CNT material. [Figure 6B] This document provides exemplary approaches for forming CNT-to-metal assemblies, which can be used individually or in combination. CNT-to-metal assemblies can be prepared by directly bonding CNT material to a metal member, by preparing the surface of the CNT material using CNT connector pads disclosed herein, by preparing the surface of the metal member using CNT material, or by any combination of the aforementioned methods disclosed herein. Figure 6A provides a block diagram illustrating an exemplary method for forming a connected CNT-to-metal assembly using CNT connector pads. Figure 6B provides a block diagram illustrating an exemplary method for forming a connected CNT-to-metal assembly by preparing the surface of a metal member using CNT material. [Figure 7] Illustrative schematic diagrams showing cross-sections of specific layered structures are provided. Figure 7 shows a layered structure of solder on electroplated metal on a CNT film. Figure 8 shows a cross-section of electroplated CNT fibers. Figure 9 shows a cross-section of CNT film / fibers wrapped around a wire. [Figure 8]Illustrative schematic diagrams showing cross-sections of specific layered structures are provided. Figure 7 shows a layered structure of solder on electroplated metal on a CNT film. Figure 8 shows a cross-section of electroplated CNT fibers. Figure 9 shows a cross-section of CNT film / fibers wrapped around a wire. [Figure 9] Illustrative schematic diagrams showing cross-sections of specific layered structures are provided. Figure 7 shows a layered structure of solder on electroplated metal on a CNT film. Figure 8 shows a cross-section of electroplated CNT fibers. Figure 9 shows a cross-section of CNT film / fibers wrapped around a wire. [Figure 10] This illustrates the use of a transfer sleeve for connecting a CNT connector pad to a metal member. The CNT connector pad is in the form of a pre-formed CNT film. Panel a shows inserting a rod covered with the CNT film into the transfer sleeve. Panel b shows applying compression and spray water to release the CNT film from the rod, transfer it to the CNT film, and transfer it into the interior of the transfer sleeve. Panel c shows the transfer sleeve loaded with the CNT film. Panel d shows inserting the metal member into the transfer sleeve loaded with the CNT film. Panel e shows applying compression and spray water to release the CNT film from the transfer sleeve, transfer the CNT film to the metal member, and thereby connect the CNT connector pad in the form of a pre-formed CNT film to the metal member. Panel f shows additional steps that may be taken to further connect the CNT connector pad and the metal member, as will be described in more detail below. [Modes for carrying out the invention]

[0031] This disclosure provides CNT materials, CNT-to-metal connectors, and CNT connector pads, each of which may be suitable for connecting CNT members (e.g., CNT members comprising or composed of the CNT materials described herein) to metal members and providing CNT-to-metal assemblies. Methods for preparing them, as well as CNT-to-metal assemblies and devices (products) containing them, are also provided herein. The CNT-to-metal assemblies provided herein generally comprise carbon nanotube (CNT) members connected to a metal member. The CNT members can be connected to the metal member via CNT-to-metal connectors, which may include CNT connector pads described herein.

[0032] The CNT-to-metal assemblies described herein may be used in a variety of environments, including DC (direct current), low power, non-harsh environments (e.g., digital electronics); DC, high power, non-harsh environments (e.g., power electronics); AC (alternating current), low power, non-harsh environments (e.g., coaxial signal transmission); AC, high power, non-harsh environments (e.g., radio RF (radio frequency)); DC, high power, harsh environments (e.g., submarine cables or power lines); and AC, low power, harsh environments (e.g., coaxial cables in aerospace).

[0033] Aligned CNT materials possess a unique combination of material properties that make them attractive for use as lightweight conductors and / or conductor reinforcing materials. For example, aligned CNT fibers are attractive for use as continuous fiber reinforcement in aluminum-metal matrix composites used in overhead power transmission lines. The CNT materials, CNT-to-metal connectors, CNT connector pads, and assemblies described herein offer further advantages in these situations by addressing transmission losses. It is estimated that approximately 6% of the total power generated in the U.S. power grid is lost due to transmission losses. This disclosure provides materials and methods for mitigating losses at connector sites as well as losses within conductors, which can significantly reduce energy consumption.

[0034] definition The technical and scientific terms used herein have the meanings generally understood by those skilled in the art in the field to which the present invention pertains, unless otherwise defined. Any suitable materials and / or methods known to those skilled in the art can be used in carrying out the present invention, taking into consideration the guidance provided herein, but specific materials and methods are described for illustrative purposes only. The materials, reagents, etc., referenced in the following description and examples are available from commercial sources unless otherwise specified.

[0035] As used herein, the singular terms “a,” “an,” “the,” and “said” include multiple referents unless the context explicitly indicates otherwise. A singular reference to an object is intended to mean “one or more,” rather than “one and only one,” unless explicitly stated otherwise.

[0036] As used herein, "about" means, when used with a number, the number itself, and plus or minus 10% of that number. For example, "about 10" should be understood as both "10" and "9 to 11".

[0037] Where used herein, the terms “e.g.,” “etc.,” “for example,” “in one example,” “in another example,” “example,” and “etc.” indicate that one or more non-limiting examples are preceded or followed. It should be understood that other examples not listed are also within the scope of this disclosure.

[0038] As used herein, the phrase in the form of "A / B" or "A and / or B" includes (A), (B), and (A and B), and the phrase in the form of "at least one of A, B, and C" includes (A), (B), (C), (A and B), (A and C), (B and C), and (A, B and C).

[0039] As used herein, the terms “comprising,” “including,” and “containing” are used broadly to mean that the described composition or method includes at least the described elements and may also include other elements not specified. The phrase “essentially consisting of” is used to include the specifically enumerated elements and additional elements that do not substantially affect the basic and novel features of the claimed invention. For example, the CNT-to-metal assembly described herein may include additional elements such as an electrical insulator (e.g., to ensure that the connector assembly is properly isolated from other connections) and / or a dopant. In some embodiments, such elements (e.g., an electrical insulator or a dopant) do not substantially affect the basic and novel features of the claimed invention.

[0040] CNT material CNT materials described herein can form good CNT-to-metal connections and exhibit good performance (e.g., good electrical performance) when connected to a metal. The CNT materials described herein (such as CNT fibers and CNT films) can be prepared by the method disclosed in U.S. Patent No. 11,111,146 (which is incorporated in whole by reference). Other documents that describe methods that can be used to prepare the CNT materials described herein include U.S. Patent Publications 2011 / 0110843, 2015 / 0298164, and 2017 / 0243668 (each of which is incorporated in whole by reference). In some embodiments, the CNT materials described herein are in the form of CNT forms. CNT forms can be prepared by methods known in the art, such as those disclosed in U.S. Patent Publication No. 2014 / 0141224A1 (which is incorporated in whole by reference). For example, a CNT foam may be produced by one or more or all of the following steps: preparing a CNT solution from CNT raw materials and a superacid to obtain a CNT solution; and solidifying the CNT solution in a mold (e.g., a mold configured to hold the CNT solution in place during solidification) to obtain a CNT foam. A CNT material exhibiting good performance (e.g., high conductivity and / or high aspect ratio as disclosed herein) can be produced when the constituent CNTs satisfy one or more or all of the following characteristics: they are aligned, p-type doped, and / or undamaged (e.g., the original length distribution of the CNTs is preserved). Typically, raw (untreated) CNTs obtained immediately after synthesis are not aligned, are semiconducting, are undoped, and typically have a log-normal length distribution. Therefore, by aligning the CNTs, p-doping the semiconducting CNTs, and / or preserving the original length distribution, a CNT material exhibiting good performance (e.g., high conductivity and / or high aspect ratio as disclosed herein) can be obtained. An exemplary example of such a process is disclosed in U.S. Patent No. 11,111,146, which is outlined below and discussed in more detail below.

[0041] For example, CNT alignment can be achieved by one or more or all of the following steps: blending and / or mixing raw CNTs with a superacid at low temperatures to form a thermodynamically stable CNT-superacid fluid; extruding the CNT-containing material (such as the CNT-superacid mixture) to obtain an extruded product; and / or allowing it to solidify (e.g., removing the solvent (e.g., superacid)). While we do not wish to be bound by theory, it is understood that the superacid protonates the CNT molecules, thereby inducing repulsive forces between the CNTs, and that the CNT molecules can be aligned as the concentration of CNTs in the solvent (e.g., superacid) increases due to excluded volume interactions. It is also thought that this process can form CNT liquid crystals. Furthermore, it is understood that in the extrusion step, shear and extensional flow fields can extend and align the liquid crystal domains in the direction of flow, achieving additional alignment of CNT molecules. Using a solidification method to remove the solvent (e.g., superacid) allows for fine control of the solvent diffusion rate (e.g., diffusion of the solvent out of the system) and the solidification pace, such as through the selection of a coagulant in which the solvent (e.g., superacid) is soluble but the CNTs are not. By fine-tuning the solidification pace, the alignment of the CNTs can be improved. For example, if solidification is too slow, the CNT molecules may become excessively relaxed, resulting in a loss of alignment after extrusion. On the other hand, if solidification is too fast, the rapid reaction between the solvent (e.g., superacid) and the coagulant may cause the breakdown of the aligned microstructure of the fluid. For example, the solidification pace may be controlled (to increase the pace) through the selection of a coagulant (e.g., acetone may solidify relatively quickly, while chloroform may solidify more slowly) and / or by facilitating exposure to a "fresh" coagulant, such as the spray solidification method disclosed in U.S. Patent No. 11,111,146.

[0042] Additionally or alternatively, p-type doping can be achieved via low-temperature blending and / or mixing of CNTs with superacidic solvents. While not bound by theory, it is thought that superacids can p-type dope semiconductor CNTs. Therefore, homogeneous blending and / or mixing of superacidic solvents and CNTs can be effective in this regard.

[0043] The retention of the original length distribution of CNTs can be achieved by performing low-temperature blending and / or mixing of CNTs (e.g., with a superacidic solvent) in a manner that reduces or minimizes shear forces (this can otherwise be applied in the normal mixing step to overcome the restricted diffusion of the solvent into the CNT raw materials). Thus, by avoiding high shear forces, CNTs will not be irreversibly damaged by the very high shear forces they might otherwise be subjected to. For example, studies have shown that sonication (e.g., sonication applied during the mixing step) can damage (e.g., break) CNTs, and therefore the average length of the CNTs may decrease, possibly due to high shear forces.

[0044] Therefore, aligned, p-doped, undamaged CNTs (e.g., those with the original length distribution of the CNTs preserved) can be obtained as described above. Although not bound by theory, alignment is thought to increase the mean free path of electrons moving within the CNT material by reducing the number of junctions between CNTs (where electrons must move from one CNT to an adjacent CNT). The resistance of junctions between CNTs is generally considered a major limiting factor in translating the remarkable conductivity of a single CNT to a macroscopic scale in a CNT material. Thus, alignment of CNTs can achieve high conductivity in CNT materials. Additionally, p-doping also increases conductivity. Meanwhile, a high aspect ratio is achieved by preventing damage (e.g., fracture) and preserving the length distribution. This is generally thought to be related to the mechanical toughness and conductivity of the finished product.

[0045] In some embodiments, the CNT material described herein is included in a CNT component (for example, a CNT component in a device such as those described above). In some embodiments, the CNT material described herein is included in a CNT connector pad described herein.

[0046] In some embodiments, the CNT material described herein comprises at least 90% by weight, at least 95% by weight, or at least 99% by weight of CNTs. The CNTs may be one or more selected from single-walled CNTs, double-walled CNTs, and multi-walled CNTs. The CNTs in the CNT material described herein may have one or more of the advantageous properties described herein.

[0047] In some embodiments, the CNT material described herein has a conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m. Additionally or alternatively, in some embodiments, the CNTs in the CNT material described herein have an average aspect ratio of at least 1000, at least 5000, or at least 10000. Additionally or alternatively, in some embodiments, the CNTs in the CNT material described herein have an average G / D ratio of at least 1, at least 10, or at least 100. In some embodiments, the CNTs in the CNT material described herein have a conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m, an average aspect ratio of at least 1000, at least 5000, or at least 10000, and an average G / D ratio of at least 1, at least 10, or at least 100.

[0048] The CNT materials described herein may or may not contain non-sp2 hybridized carbon material. In some embodiments, the CNT materials described herein contain less than 20% by weight, less than 10% by weight, or less than 5% by weight of non-sp2 hybridized carbon material. In some embodiments, the CNT materials described herein are substantially free of non-sp2 hybridized carbon material. In some embodiments, non-sp2 hybridized carbon material is not present in the CNT material. As used herein, the term “substantially free” means that the material (e.g., non-sp2 hybridized carbon material) is below the detection limit of TGA (thermogravimetric analysis), and the term “not present” means that the material is below the detection limit of EELS (electron energy loss spectroscopy).

[0049] The CNT materials described herein may or may not contain impurities such as metal particle impurities. In some embodiments, the CNT materials described herein contain less than 10% by weight, less than 5% by weight, or less than 2% by weight of metal particle impurities. In some embodiments, the CNT materials described herein are substantially free of metal particle impurities, and in some embodiments, metal particle impurities are not present in the CNT material. While not bound by theory, it is believed that in certain applications, such as AC signal transmission applications, the presence of ferromagnetic compounds (e.g., Fe) may introduce distortion to the signal, such as passive intermodulation (PIM). Therefore, it can be advantageous if the metal content in the CNT material (e.g., due to residual metal catalyst particles in the CNT material used as a CNT component or CNT connector pad described herein) is negligibly low in such applications. Additionally or alternatively, in certain applications, such as RF applications, the presence of ferromagnetic compounds (e.g., Fe) may introduce additional loss mechanisms. Therefore, it can be advantageous if the metal content in the CNT material is negligibly low in such applications as well.

[0050] CNT materials can have any density suitable for their intended use (e.g., type of device and / or type of use). In some embodiments, the CNT material has a density of at least 1 g / cm³.3 、at least 1.2 g / cm 3 、or at least 1.4 g / cm 3 in density.

[0051] As described above, the CNT materials used in this specification may exhibit one or more or all of the properties (including the above properties) described in this specification.

[0052] When the CNT material is part of a CNT member (e.g., a CNT member that includes or is composed of the CNT material), the form of the CNT member can vary depending on the specific application. For example, the CNT member may be a CNT coating, a CNT film, a CNT foam, or a CNT fiber.

[0053] Without being bound by theory, selecting and using a CNT material that exhibits one or more or all of the above properties is thought to be able to address and / or overcome one or more of the problems discussed above that occur when connecting a CNT member to a metal member. For example, using a CNT material with a high density may reduce unwanted voids. Using a CNT material with high conductivity may reduce contact resistance. Using a CNT material with a high aspect ratio may improve the fatigue resistance of the CNT material and make the connector site less likely to be damaged in difficult use cases (e.g., those involving a chemically harsh environment and / or those involving mechanical / thermal cycles). Using a CNT material with a high G / D ratio may improve the chemical and thermal resistance of the CNT material and make the connector site less likely to be damaged in difficult use cases. Using a CNT material having one or both of a high G / D ratio and a high aspect ratio may improve conductivity.

[0054] CNT connector pad Using the CNT material described above, a CNT connector pad (for example, a connector pad that can function as an interface between a CNT member and a metal member, or as an interface between a CNT member and another CNT-to-metal connector) may be formed. Although not bound by theory, the mechanical properties of the CNT connector pad described herein are considered to allow for mechanical compression without damage. Additionally, if the conductivity is high, it is possible to minimize losses at the interface between the CNT member and the metal member.

[0055] As will be discussed in more detail below, CNT-to-metal assemblies are also provided herein. A CNT-to-metal assembly comprises CNT members and metal members, which are connected via CNT connector pads used alone or in conjunction with other CNT-to-metal connectors. This disclosure includes CNT connector pads themselves and CNT connector pads present in CNT-to-metal assemblies.

[0056] The CNT connector pads described herein comprise the CNT material described herein and, for example, possess one or more or all of the above advantageous properties. As a non-limiting example, the CNT connector pads described herein may be prepared from a CNT material comprising CNTs having conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m, and an average aspect ratio of at least 1000, at least 5000, or at least 10000, wherein the CNT material has an average G / D ratio of at least 1, at least 10, or at least 100. Additionally or alternatively, the CNT material of the CNT connector pad may comprise less than 20% by weight, less than 10% by weight, or less than 5% by weight of non-sp2 hybridized carbon material. Additionally or alternatively, the CNT material of the CNT connector pad may comprise less than 10% by weight, less than 5% by weight, or less than 2% by weight of metallic particulate impurities. Additionally or alternatively, the CNT material of the CNT connector pad may comprise at least 1 g / cm³ 3 at least 1.2 g / cm³ 3 , or at least 1.4 g / cm³ 3The density may be such that the CNT connector pad may contain at least 90% by weight, at least 95% by weight, or at least 99% by weight of CNTs.

[0057] The form of the CNT connector pad described herein is not particularly limited. Generally, the CNT connector pad is a form or configuration that can be placed on, formed on, wrapped around (or tied to), surround, or cover a metal member (e.g., a metal member of an assembly). In some embodiments, the CNT connector pad described herein is in the form of a pre-formed film or foam of CNT material. In some embodiments, the CNT connector pad described herein is a film, foam or coating of CNT material formed directly on the surface of a member of an assembly (e.g., a film, foam or coating formed directly on the surface of a metal member of an assembly). In some embodiments, the CNT connector pad described herein is formed from CNT fibers. In some aspects of any of these embodiments, the CNT connector pad described herein is a separate structure from the CNT member of the assembly. In other aspects of any of these embodiments, the CNT connector pad described herein is an area of ​​the CNT member of the assembly.

[0058] In some embodiments, the CNT connector pad can conform to a non-planar surface (e.g., a non-planar surface of a metal component of an assembly) by, for example, having sufficient flexibility to conform to a non-planar surface and / or having a shape complementary to the non-planar surface.

[0059] The CNT connector pads described herein can be manufactured in any desired shape. For example, the CNT connector pad may be square, circular, or any centrally symmetric shape suitable for through-type connectors. For end-launch type connectors, the CNT connector pad may be rectangular, semicircular, or symmetric with respect to the central axis. The CNT connector pad may include concentric rectangular traces, spirals, or be arranged in an orientation selected to optimize resonance with adjacent metal resonant circuits for inductive connectors.

[0060] CNT connector pads can be prepared as pre-formed films or foams for wrapping around (or tying, including making knots) a metal member (e.g., in the form of a “tape”). CNT connector pads can be formed from, or in the form of, one or more fibers, e.g., one or more fibers that can be wrapped around (or tied) a metal member. CNT connector pads can be in the form of pre-formed films or foams, generally having a cylindrical shape (with or without a cap) for wrapping a metal member (optionally, for use with a transfer sleeve, as will be described in more detail below). CNT connector pads can be films, foams, or coatings formed from a fluid phase onto the surface of a metal member (as will be described in more detail below).

[0061] In some embodiments, the CNT connector pad consists of a single layer of the CNT material described herein. In some embodiments, such a single-layer CNT connector pad has a thickness of about 1 μm to about 10 μm, including, for example, about 1 μm, about 2 μm, about 3 μm, about 4 μm, about 5 μm, about 6 μm, about 7 μm, about 8 μm, about 9 μm, or about 10 μm, or any value in between. In some embodiments, the single-layer CNT connector pad is formed by wrapping (or tying) CNT fibers or a pre-formed CNT film or foam around a metal member. In some embodiments, the single-layer CNT connector pad is formed by applying a pre-formed film, generally having a cylindrical shape (with or without a cap), to enclose the metal member (as will be described in more detail below). In some embodiments, the single-layer CNT connector pad is formed on the surface of a metal member from a fluid phase (as will be described in more detail below).

[0062] In some embodiments, the CNT connector pad comprises multiple layers of the CNT material described herein (e.g., a multilayer CNT connector pad). In some embodiments, the multilayer CNT connector pad has a thickness of about 1 μm to about 0.5 mm, including, for example, about 1 μm, about 10 μm, about 50 μm, about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm, or about 0.5 mm, or any value in between. In some embodiments, the multilayer CNT connector pad is formed by winding (or tying) a pre-formed CNT film or foam, or one or more CNT fibers, around a metal member until multiple layers are formed. In some embodiments, the multilayer CNT connector pad is formed by applying multiple layers of separate pre-formed CNT films or foams to the surface of a metal member to form multiple layers. In some embodiments, the multilayer CNT connector pad is formed in situ from a fluid phase, and the layers are formed directly on the surface of the metal member from the fluid phase.

[0063] In some embodiments, the CNT connector pad comprises multiple layers of CNT material, wherein the multiple layers include an outer layer of CNT material and one or more intermediate layers of CNT material, with the "outer" layer being close to the CNT member and far from the metal member, and the "intermediate" layer being close to / on top of the metal member. In some embodiments, a thin film may be provided in which one or more of the intermediate layers contain a conductive material (e.g., a metal or other conductive material). According to such embodiments, the film may be provided by any preferred method such as sputtering, electroplating, or vapor deposition. In some embodiments, the film comprises one or more metals selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W. As used herein, the "thin" film may have a thickness in the range of 1 nm to 100 μm (0.1 mm). Depending on the application and environmental conditions, some metals may be preferred over others to provide a high surface area metal interface for electrical connection to the CNT material.

[0064] Another property that can be selected and controlled to achieve desired characteristics is the alignment of CNTs. In some contexts, CNT alignment is a preferred structure for achieving certain high-performance characteristics. However, the introduction of anisotropic conductivity in the connector portion can have detrimental effects on the performance of the connector in certain applications. In that context, it may be advantageous to use a CNT connector pad comprising a single layer of aligned or unaligned CNT material as described herein, or multiple layers of aligned CNT material as described herein, where these layers have different orientations relative to each other. For example, in some embodiments, a CNT connector pad comprising multiple layers of CNT material as described herein may comprise a first layer of CNT material (e.g., CNT material as described herein) and a second layer of CNT material (e.g., CNT material as described herein), where the first and second layers are arranged in different orientations relative to each other. For example, in a CNT connector pad consisting of five layers, the layers can be aligned in increments of approximately 36 degrees to cover a total of 180 degrees. As another example, the orientation of the alignment of the CNT connector pad layers can be selected to design different antenna characteristics. For example, aligning the CNT connector pad layers perpendicular to the direction of current transport can produce a broader bandwidth (lower Q) resonance, while aligning them parallel to the direction of current transport can produce a narrower bandwidth (higher Q) resonance. In these embodiments, the CNT material of each layer may be the CNT material described herein, and optionally, each layer may consist of the same CNT material, or one or more layers may consist of different CNT materials, each having the structure and properties described herein.

[0065] As described above, the CNT connector pads described herein are advantageously used as interfaces for CNT-to-metal assemblies, for example, to connect CNT members to metal members. Additionally or alternatively, as described above, the CNT connector pads described herein are advantageously used as interfaces for CNT-to-metal assemblies, for example, to connect CNT members to metal members via other CNT-to-metal connectors, such as CNT-to-metal connectors known in the art. Unless otherwise specified, in any embodiment and configuration described herein, in any given assembly, the CNT material of the connector pad may be the same as or different from the CNT material of the CNT member.

[0066] In the context of CNT members that are CNT coatings, bonding a typical CNT-to-metal connector to a thin layer of a soft CNT member can damage the CNT member, particularly during thermal and mechanical cycling. In contrast, the CNT connector pads described herein can provide a durable, conformal, and highly conductive interface (between a CNT member and a metal member, or between a CNT member and another CNT-to-metal connector). The CNT connector pads can protect the underlying thin CNT coating by dissipating both mechanical and thermal energy from the connector and the environment while ensuring a stable electrical connection.

[0067] In the context of CNT members that are CNT films or foams, if the film or foam area is limited, the CNT connector pads described herein may be formed from the same material as the CNT film or foam (for example, they may be part of the same structure as the CNT member, for example, they may be a region of the CNT member), or they may be attached to the CNT film or foam as a reinforcing material.

[0068] In the context of CNT members, which are CNT fibers composed of thin CNT filaments that cannot provide a large surface area at the interface with the connector, the CNT connector pads described herein can be connected to the ends of the fibers to provide a larger, more durable, and lower contact resistance area to facilitate interfacing with metal or another CNT-to-metal connector.

[0069] The use of connector pads and / or surface preparation and bonding methods disclosed herein can enhance connections compared to conventional CNT-to-metal connections by reducing surface roughness at the connection site, reducing voids, increasing the contact area, and providing good contact resistance.

[0070] Connected Assembly In another embodiment, the Disclosure provides assemblies (e.g., CNT-to-metal assemblies) comprising carbon nanotube (CNT) members connected to a metal member. The assemblies described herein (e.g., CNT-to-metal assemblies) may exhibit one or more of the following advantageous properties: For example, the assemblies described herein (e.g., CNT-to-metal assemblies) may exhibit advantageous signal attenuation. In some embodiments, the assemblies described herein may have a signal attenuation of 20 dB to 30 dB. In some embodiments, the assemblies described herein may have a signal attenuation of 10 dB to 20 dB. In some embodiments, the assemblies described herein may have a signal attenuation of 5 dB to 10 dB. Additionally or alternatively, the assemblies described herein may exhibit an advantageous signal-to-noise ratio (e.g., 2:1 to 100:1 or higher). In some embodiments, the assemblies described herein may have a signal-to-noise ratio of 2:1 to 5:1. In some embodiments, the assemblies described herein may have a signal-to-noise ratio of 5:1 to 20:1. In some embodiments, the assemblies described herein may have a signal-to-noise ratio of 20:1 to 100:1. Additionally or alternatively, the assemblies described herein may have phase shift characteristics favorable to the original signal entering the assembly. In some embodiments, the assemblies described herein may have a phase shift of less than pi / 12rad. In some embodiments, the assemblies described herein may have a phase shift of less than pi / 24rad. In some embodiments, the assemblies described herein may have a phase shift of less than pi / 96rad. Additionally or alternatively, the assemblies described herein may exhibit temperature difference characteristics favorable to the steady-state temperature of the metal members. In some embodiments, the assemblies described herein may have a temperature difference of less than 25°C with respect to the steady-state temperature of the metal members. In some embodiments, the assemblies described herein may have a temperature difference of less than 15°C. In some embodiments, the assemblies described herein may have a temperature difference of less than 5°C.

[0071] In this context, the CNT members of the assemblies described herein (e.g., CNT-to-metal assemblies) include or consist of the CNT material described herein and have, for example, one or more or all of the advantageous properties described herein.

[0072] Examples of CNT components include, but are not limited to, display electrodes, touchscreen electrodes, energy harvesting electrodes, solar cell electrodes, battery electrodes, electrostatic dissipation elements, grounding elements, resistive heating elements, strain detection elements, chemical sensor elements, antenna radiating elements, antenna grounding surfaces, coaxial cable outer shields, coaxial cable inner conductors, smart sheathing for on-site wear monitoring, resistive elements for other sensors, capacitive elements for other sensors, inductive elements for other sensors, biosensing elements for muscle or nerve activity, muscle and / or nerve stimulating electrodes, DC power cables and transmission lines, AC power cables and transmission lines, field emitters, transformer coils, DC motor coils, electronic textiles, transistors, conductors, capacitors, or inductors.

[0073] Examples of metal components include, but are not limited to, metal matrices, metal wires, metal cables, ring terminals, circuit board terminals, quick disconnect terminals, spade terminals, hook terminals, snap plug terminals, battery terminals, battery terminal clamps, battery springs, grounding blocks, butt splices, wire ferrules, terminal blocks, compression lugs, set screw lugs, BNC (Bayonet Neill-Concelman) connectors, TNC (Threaded Neill-Concelman) connectors, RCA (Radio Corporation of America) connectors, SMA (SubMiniature version A) connectors, SMC (SubMiniature version C) connectors, FFC (Flat Flexible Cable) connectors, FPC (Flexible Printed Circuit) connectors, DIN (Deutsches Institut für Normung) connectors, and F-type connectors.

[0074] As a non-limiting example, a CNT member may include or be composed of a CNT material containing CNTs having conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m, and an average aspect ratio of at least 1000, at least 5000, or at least 10000, wherein the CNT material has an average G / D ratio of at least 1, at least 10, or at least 100. Additionally or alternatively, the CNT material of a CNT member may contain less than 20% by weight, less than 10% by weight, or less than 5% by weight of non-sp2 hybridized carbon material. Additionally or alternatively, the CNT material of a CNT member may contain less than 10% by weight, less than 5% by weight, or less than 2% by weight of metal particulate impurities. Additionally or alternatively, the CNT material of a CNT member may contain at least 1 g / cm³ 3 at least 1.2 g / cm³ 3 , or at least 1.4 g / cm³ 3 It may have a density of . The CNT material of the CNT member may contain at least 90% by weight, at least 95% by weight, or at least 99% by weight of CNTs.

[0075] In some embodiments, the metal components of the assemblies described herein may be or include a metal matrix, or any metal connector such as wires (e.g., solid core or braided wire), metal cables, plugs, lugs, ferrules, wire nuts, spade terminals, hook terminals, ring terminals, block terminals, pin terminals, etc. The metal components may include or be composed of any metal such as one or more metals selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W.

[0076] In some embodiments, the CNT member is connected to the metal member via a CNT-to-metal connector described herein. In some embodiments, the connector pad described herein functions as a CNT-to-metal connector. In other embodiments, the CNT-to-metal connector is a conventional CNT-to-metal connector (e.g., a CNT-to-metal connector known in the art). In other embodiments, the CNT-to-metal connector includes a CNT connector pad described herein and another CNT-to-metal connector (e.g., a CNT-to-metal connector known in the art).

[0077] In some embodiments, the CNT-to-metal connector member comprises a material selected from graphene, a metal, and a metal-containing epoxy. In some embodiments, the graphene is dispersed in a slurry, paste, or suspension. In some embodiments, the metal is one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W. In some embodiments, the metal-containing epoxy is a silver-containing epoxy.

[0078] As described above, in some embodiments, the CNT-to-metal connector described herein further includes a CNT connector pad (e.g., the CNT connector pad described herein). The surface of the CNT connector pad may be connected to a standard metal connector by any preferred means, for example, via a reactive foil containing Al / Ni / Sn solder (or other metal compounds) and / or by applying one or more of pressure, current (e.g., for resistive heating) and heat to the CNT / connector / foil assembly (e.g., to the interface).

[0079] In some embodiments, the CNT-to-metal connectors described herein do not include the CNT connector pads described herein.

[0080] Accordingly, in some embodiments, assemblies comprising carbon nanotube (CNT) members connected to a metal member are provided herein, wherein the CNT members are connected to the metal member via CNT-to-metal connectors comprising (a) a material selected from graphene, metal, and metal-containing epoxy.

[0081] According to any of these embodiments, the joint (interface) between the CNT material (of the CNT member or CNT connector pad) and the CNT-to-metal connector or metal may be wrapped (or tied) with CNT fibers. In some embodiments, the CNT fibers are tied for further durability. In some embodiments, the CNT fibers are the CNT material described herein and have, for example, one or more or all of the advantageous properties described herein.

[0082] Additionally or alternatively, according to any embodiment of the assembly, a thin film comprising a conductive material, such as a metal or other conductive material, may be provided on the surface of the CNT material (of the CNT member or CNT connector pad). According to such embodiments, the film may be provided by any preferred method such as electroplating, sputtering, or vapor deposition. In some embodiments, the film comprises one or more metals selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W. As used herein, the “thin” film may have a thickness in the range of 1 nm to 100 μm (0.1 mm). Thus, the surface described herein (e.g., the surface of the CNT material (of the CNT member or CNT connector pad)) can be made more wettable for subsequent soldering, brazing, fusion, or welding. The wetted surface can then be soldered, brazed, welded, or fused to form a connection with a metal connector via the use of a suitable metal filler compound. Metals typically do not readily wet CNTs, considering their irregular surface topology, as shown in the following examples, for example. However, the inventors have found that good metal coverage can be achieved with the CNT materials described herein.

[0083] When the flexibility of CNT material is a problem in connector applications, nickel (Ni) metal can be particularly interesting. Although not bound by theory, since Ni is a hard metal, it is thought that even a small amount of Ni can impart significant rigidity to the CNT material. Additionally, because Ni is corrosion-resistant and stable at high temperatures, it can stabilize dopants (e.g., acidic dopants) from solution treatment in superacids. Therefore, in any particular embodiment of the assembly configuration, a thin film containing Ni may be provided on the surface of the CNT material (of the CNT member or CNT connector pad).

[0084] In metal can also be of particular interest if its low melting point is advantageous for manufacturing equipment, etc. Therefore, in any particular embodiment of the assembly embodiment, a thin film containing In may be provided on the surface of the CNT material (of the CNT member or CNT connector pad). In any other particular embodiment of the assembly embodiment, a thin film containing Cu may be provided on the surface of the CNT material (of the CNT member or CNT connector pad).

[0085] Additionally or alternatively, according to any embodiment of the assembly, the surface of the CNT material (of the CNT member or CNT connector pad) may be coated with a conductive compound such as silver epoxy, other solder paste, conductive polymer, or metal-filled epoxy (e.g., metal-filled polymer) to facilitate electrical contact with mechanical connections such as crimp connectors or spring connectors.

[0086] Assembly manufacturing method In another embodiment, a method for fabricating an assembly (e.g., a CNT-to-metal assembly as described herein) is provided herein.

[0087] In some embodiments, the assembly is prepared by directly bonding CNT material (e.g., CNT material of a CNT member) to a metal member. In some embodiments, the assembly includes a CNT connector pad as described herein. Thus, a method for preparing an assembly as described herein may include providing a CNT connector pad as disclosed herein to the surface of a CNT material (e.g., CNT material of a CNT member). Once the CNT connector pad is provided on the CNT material (e.g., CNT material of a CNT member), the subassembly can be connected to a metal member. Additionally or alternatively, a method for preparing an assembly as described herein may include providing a CNT connector pad as disclosed herein to the surface of a metal member. Once the CNT connector pad is provided on the metal member, the subassembly can be connected to the CNT material (e.g., CNT material of a CNT member). More specific embodiments are described in more detail below.

[0088] Connection of CNT connector pad to CNT component In some embodiments, a method for manufacturing an assembly as described herein may include connecting a CNT connector pad (e.g., a CNT connector pad as described herein) to a CNT member (e.g., a CNT member as described herein), each of which independently comprises or is composed of a CNT material as described herein (e.g., having one or more or all of the advantageous properties described herein).

[0089] In some embodiments, a method for connecting a CNT connector pad to a CNT member includes bringing the CNT member and the CNT connector pad into contact at an interface, and optionally further including crimping and / or clamping the CNT member and the CNT connector pad together.

[0090] In some embodiments, a method for connecting a CNT connector pad to a CNT member involves evaporating a solvent at the interface to connect the CNT member to the CNT connector pad via capillary action. In some embodiments, the solvent is one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether). In some embodiments, one or more of pressure, current (e.g., for resistive heating), and heat may be used at the interface to assist in forming a connection between the CNT member and the CNT connector pad.

[0091] In some embodiments, the method for connecting a CNT connector pad to a CNT member involves solvent welding the CNT connector pad to the CNT member using an acid (e.g., a strong acid or superacid). In some embodiments, the strong acid or superacid is one or more selected from Bronsted strong or superacids, Lewis strong or superacids, conjugated Bronsted-Lewis strong or superacids, and any two or more combinations thereof. In some embodiments, the strong acid or superacid is one or more selected from sulfuric acid, perchloric acid, chlorosulfonic acid, fluorosulfonic acid, trifluoromethanesulfonic acid, perfluoroalkanesulfonic acid, antimony pentafluoride, arsenic pentafluoride, oleum, polyphosphate-oleum mixture, tetra(hydrogen sulfate)boric acid-sulfuric acid, fluorosulfuric acid-antimony pentafluoride, fluorosulfuric acid-SO3, fluorosulfuric acid-arsenic pentafluoride, fluorosulfonic acid, fluorosulfonic acid-hydrogen fluoride-antimony pentafluoride, fluorosulfonic acid-antimony pentafluoride-sulfur trioxide, fluoroantimonic acid, tetrafluoroboric acid, trifluic acid, and any two or more combinations thereof. In some embodiments, the strong acid or superacid is provided in a solution containing CNTs (of the CNT member) in an amount of up to about 20% by weight, for example, up to 15% by weight or up to 10% by weight.

[0092] In some embodiments, a method for connecting a CNT connector pad to a CNT member includes mechanically joining the CNT connector pad to the CNT member, for example, passing CNT fibers through the CNT connector pad and the CNT member. In some embodiments, the CNT fibers are CNT materials as described herein, having, for example, one or more of the advantageous properties described herein.

[0093] Connection of CNT connector pads or CNT members to metal members In some embodiments, the method for manufacturing the assembly described herein includes connecting a CNT member (e.g., a CNT member described herein) or a CNT connector pad (e.g., a CNT connector pad described herein) to a metal member (e.g., a metal member described herein). As will be discussed in more detail below, in some embodiments, the surface of the metal member is coated with a CNT film or foam (e.g., coated as a fluid phase) to provide a CNT connector pad on the metal member. Additionally or alternatively, as will be discussed in more detail below, in some embodiments, the surface of the metal member is mechanically bonded to a pre-formed CNT connector pad, such as a solid CNT film or CNT foam. Additionally or alternatively, as will be discussed in more detail below, in some embodiments, the surface of the metal member is mechanically bonded to a pre-formed CNT connector pad, for example, by wrapping (or tying) it with a pre-formed CNT film or foam or CNT fibers.

[0094] In some embodiments, the method for fabricating the assembly described herein includes directly connecting CNT members to a metal member (e.g., without CNT connector pads). Such a method may include (i) bringing the CNT material of the CNT member and (ii) the metal member into contact at an interface to form a joint of the assembly. In some embodiments, the method may include crimping and / or clamping (i) with (ii) to form a joint of the assembly. In some embodiments, the method may include the following steps: wrapping (or tying) the joint with CNT fibers or film or foam; electroplating the surface of the CNT material of the CNT member with a metal (e.g., the metal includes one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W); and electroplating the surface of the CNT material of the CNT member with a metal (e.g., the metal includes one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, P The method may include sputter coating with one or more selected from t, Pd, Pb, Mo, Mg, Rh, and W; wetting the surface of the CNT material of the CNT member before the soldering or brazing step; soldering or brazing the CNT material of the CNT member to the metal member; providing a conductive metal-filled epoxy to the interface; and applying a reactive foil containing metal solder to the interface using one or more selected from pressure, current, and heat. In some embodiments, the method may include potting, heat shrinking, or molding the assembly obtained from the steps described above.

[0095] In other embodiments, the method for manufacturing the assembly described herein uses the CNT connector pad described herein. In such embodiments, the method may include connecting a CNT connector pad (optionally already connected to a CNT member) to a metal member using a methodology similar to the above-described method for directly connecting a CNT member to a metal member. For example, the method may include (i) bringing the CNT material of the CNT connector pad (optionally already connected to a CNT member) and (ii) the metal member into contact at an interface to form a joint of the assembly. In some embodiments, the method involves the following steps: wrapping (or tying) the joint with CNT fibers, film, or foam; electroplating the surface of the CNT material of the CNT connector pad with a metal (for example, the metal includes one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W); and plating the surface of the CNT material of the CNT connector pad with a metal (for example, the metal includes Cu, In, Ni, Ag, Au, Sn, Al, Zn, P The method may include sputter coating with one or more selected from t, Pd, Pb, Mo, Mg, Rh, and W; wetting the surface of the CNT material of the CNT connector pad before the soldering or brazing step; soldering or brazing the CNT material of the CNT connector pad to a metal member; providing a conductive metal-filled epoxy to the interface; and applying a reactive foil containing metal solder to the interface using one or more selected from pressure, current, and heat. In some embodiments, the method may include potting, heat shrinking, or molding the assembly obtained from the steps described above.

[0096] As described above, in some embodiments, the CNT connector pad is in the form of a pre-formed CNT film or foam or CNT fibers. In such embodiments, the method may include bringing the pre-formed CNT film or foam or CNT fibers and the metal member into interface contact to form the bond described above, and optionally performing one or more or all of the additional steps outlined above. Additionally or alternatively, the method may include wrapping (or tying, including making a knot) the metal member with the pre-formed CNT film or foam or CNT fibers. Additionally or alternatively, the method may include inserting the metal member into a pre-formed CNT film or foam having a generally cylindrical shape (with or without a cap) (optionally using a transfer sleeve as discussed below). Any such embodiment may further optionally include performing one or more or all of the additional steps outlined above. In some embodiments, wrapping (or tying) can be achieved by extruding the pre-formed CNT film or foam or CNT fibers onto the metal member while the metal member is rotating. In any embodiment, as described above, a single-layer CNT connector pad or a multi-layer CNT connector pad can be achieved by applying a pre-formed CNT film or foam or CNT fibers, thereby achieving any of the above embodiments of CNT connector pads.

[0097] As described above, in some embodiments, the method may provide a CNT connector pad, prepared in the form of a pre-formed CNT film or CNT foam having a generally cylindrical shape (with or without a cap), to a metal member using a transfer sleeve, as shown in Figure 10. For use in such embodiments, the transfer sleeve is generally cylindrical and sized and shaped to mate with the metal member. This allows the transfer sleeve to be positioned around the metal member and / or the metal member to be inserted into the transfer sleeve, and the CNT connector pad can be transferred from the transfer sleeve to the metal member according to the method. To facilitate such transfer, the internal dimensions of the transfer sleeve may be designed to provide a "tight fit" with the metal member. Typically, the transfer sleeve will have a length that correlates with the dimensions of the pre-formed CNT film or foam to be transferred, such as being at least the same length as the corresponding dimensions of the pre-formed CNT film or foam to be transferred. Advantageously, the transfer sleeves described herein are made of a material having low surface energy and low surface area to facilitate transfer. Additionally or alternatively, the transfer sleeves described herein may be made of a flexible material (e.g., a material that can be sufficiently deformed without suffering irreversible damage during the transfer step). For example, the transfer sleeves described herein may be made of one or more materials selected from high-density polyethylene (HDPE), polypropylene (PP), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), ethylene tetrafluoroethylene (ETFE), and polytetrafluoroethylene (PTFE). In some embodiments, the transfer sleeve is a single-use sleeve. In some embodiments, the transfer sleeve is a multi-use sleeve. For example, the transfer sleeve may be used for up to 10,000 transfer cycles.

[0098] As shown in Figure 10, the method generally involves transferring a pre-formed CNT film or foam (CNT connector pad) from the inside of a transfer sleeve to the surface of a metal member (see panels c-f of Figure 10). In some embodiments, the method may first involve transferring the pre-formed CNT film or foam from a support (shown as a rod in panels a-b of Figure 10) into the inside of the transfer sleeve, for example, by a process including compressing the sleeve over / around the support carrying the pre-formed CNT film or foam, and optionally wetting it (e.g., spraying with water) to obtain a transfer sleeve loaded with the pre-formed CNT film or foam (see panels a-c of Figure 10). Alternatively, the CNT film or CNT foam may be loaded into the transfer sleeve by directly forming the CNT film or CNT foam on the inner surface of the transfer sleeve from a fluid phase, by preparing the CNT film or CNT foam in situ inside the transfer sleeve, for example, by using the processes generally described below for directly forming a CNT film on a metal surface.

[0099] To transfer a pre-formed CNT film or foam from a transfer sleeve to a metal member, the loaded transfer sleeve may be positioned around the metal member and / or the metal member may be inserted into the transfer sleeve, and then the sleeve may be compressed over / around the metal member, or optionally, the pre-formed CNT film or foam may be transferred to the metal member by wetting it (e.g., by spraying with water) (see panels d-e of Figure 10). After the metal member (provided here with the CNT connector pads of the CNT film or foam) is removed from the transfer sleeve, the method may further include one or more additional steps to further connect the CNT connector pads to the metal member, as discussed below: for example, applying further compression, evaporating a solvent (e.g., acetone) to promote densification via capillary action, and applying heat or electric current (e.g., for resistive heating) (see panel f of Figure 10).

[0100] The properties of the support are not important, but it should be of appropriate dimensions for supporting a pre-formed CNT film (CNT connector pad) and being inserted into a transfer sleeve. Therefore, it generally has the same cross-sectional dimensions as the metal member and a length at least the same as or greater than the pre-formed CNT film (optionally, longer than the transfer sleeve). The support typically includes suitable materials for supporting and transferring the pre-formed CNT film (CNT connector pad), such as polytetrafluoroethylene (PTFE), titanium, Hastelloy, and fluorinated ethylene propylene (FEP).

[0101] According to these embodiments, the pre-formed CNT film or CNT foam (CNT connector pad) can be prepared by any preferred method such that the pre-formed CNT film or CNT foam suitable for use as a CNT connector pad as described herein is positioned on the support so that it can be transferred from the solid support to the transfer sleeve as described above. For example, in some embodiments, the pre-formed CNT film or CNT foam (e.g., the pre-formed CNT film or CNT foam to be transferred to the transfer sleeve) is positioned on the support by winding the CNT film or CNT foam or one or more CNT fibers around the support. Additionally or alternatively, in some embodiments, the pre-formed CNT film or CNT foam (e.g., the pre-formed CNT film or CNT foam to be transferred to the transfer sleeve) is formed directly from a fluid phase onto the surface of the solid support (described in more detail below). Alternatively, in some embodiments, a pre-formed CNT film or CNT form (e.g., a pre-formed CNT film or CNT form transferred via a transfer sleeve) is formed directly from the fluid phase to the transfer sleeve (e.g., directly onto the inner surface of the transfer sleeve) by using, for example, the process generally described below for directly forming a CNT film on a metal surface.

[0102] As described above, in other embodiments, the CNT connector pad (e.g., composed of a CNT film or foam as described herein) is formed directly from the fluid phase onto the surface of the metal member. Such a method may include one or more or all of the following steps: preparing a CNT fluid; dipping the metal member in the CNT fluid; withdrawing the metal member from the CNT fluid; solidifying the coated CNT fluid (i.e., the CNT fluid coated on the surface of the metal member); and cleaning the CNT-coated metal member.

[0103] CNT fluids may be prepared as described in U.S. Patent No. 11,111,146 (the whole of which is incorporated herein by reference). For example, a CNT fluid may be prepared by one or more or all of the following steps: blending a carbon nanotube starting material (e.g., raw CNTs such as untreated CNTs in powder form) with solid solvent particles of a carbon nanotube solvent; then activating the solvent (e.g., by heating, etc., to obtain the carbon nanotube solvent); and mixing to obtain a CNT fluid. Alternatively, a CNT fluid may be prepared by one or more or all of the following steps: blending a carbon nanotube starting material with a carbon nanotube solvent precursor; then reacting the solvent precursor with a solvent activator to obtain the carbon nanotube solvent; and mixing to obtain a CNT fluid. The CNT fluid can be optionally extruded onto the surface of a metal component, for example, by an extrusion step, followed by a solidification step. In some embodiments, the solidification step includes exposure to an infrared radiation source, optionally, the infrared radiation being of a wavelength that reduces the absorption of radiation by the nanotube solvent compared to the absorption of radiation by the carbon nanotubes. Additionally or alternatively, in some embodiments, the solidification step includes exposure to a chemical coagulant, which is a solvent for the carbon nanotube solvent and a non-solvent for the carbon nanotubes (e.g., a mixture of acetone, water, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), ether, chloroform, and sulfuric acid in water). Additionally or alternatively, a washing step may be performed to remove, for example, residual traces of the carbon nanotube solvent and / or by-products formed during the process.

[0104] According to these embodiments, the carbon nanotube solvent is a solvent capable of dissolving carbon nanotube starting materials. Exemplary nanotube solvents include acids (e.g., chlorosulfonic acid (HSO3Cl), fluorosulfonic acid, fluorosulfuric acid, hydrochloric acid, methanesulfonic acid, nitric acid, hydrofluoric acid, fluoroantimonic acid, magic acid, and other carborane acids) and supercritical fluids (e.g., supercritical carbon dioxide). As used herein, a supercritical fluid is a substance at a temperature and pressure above its critical point. In some embodiments, the solid solvent particles are frozen nanotube solvent particles, such as low-temperature frozen nanotube solvent particles.

[0105] According to these embodiments, the solvent precursor material is a chemical compound that cannot dissolve carbon nanotube starting material on its own, but can be mixed with and / or reacted with a solvent activator to produce a carbon nanotube solvent. The solvent precursor material may be a solid material such as phosphorus pentachloride in powder form, which can be activated using sulfuric acid as a solvent activator to obtain a carbon nanotube solvent.

[0106] In any of these different embodiments for connecting a CNT connector pad to a metal member, the method may further include one or more of the following additional steps for further connecting the CNT connector pad to the metal member: applying and evaporating a solvent (e.g., one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether)) to promote densification via capillary action; applying pressure (optionally, providing mechanical compression using a tape such as a fluorinated ethylene propylene (FEP) tape with a silicone adhesive); applying electric current (e.g., for resistive heating); and applying heat.

[0107] Connection of CNT to metal connector to CNT member or metal member In some embodiments, the assembly described herein includes a CNT-to-metal connector, and a method for manufacturing such an assembly includes connecting the CNT-to-metal connector directly to a CNT member (e.g., a CNT member described herein) or via a CNT connector pad (e.g., a CNT connector pad described herein). In some embodiments, the method includes connecting the CNT-to-metal connector to a metal member (e.g., a metal member described herein).

[0108] In some embodiments, the method includes bringing (i) a CNT member and (ii) a CNT-to-metal connector (optionally connected to the metal member (directly or via a CNT connector pad)) into interface contact to form a joint of the assembly. In some embodiments, the method includes the following steps: wrapping (or tying, including making knots) the joint with CNT fibers or film; electroplating the surface of the CNT material of the CNT member with a metal (e.g., the metal includes one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W); and electroplating the surface of the CNT material of the CNT member with a metal (e.g., the metal includes Cu, In, Ni, Ag, Au, Sn, Al, Zn, P The method may include sputter coating with one or more selected from t, Pd, Pb, Mo, Mg, Rh, and W; wetting the surface of the CNT material of the CNT member before the soldering or brazing step; soldering or brazing the CNT material of the CNT member to the CNT-to-metal connector; providing a conductive metal-filled epoxy at the interface; and applying a reactive foil containing metal solder to the interface using one or more selected from pressure, current, and heat. In some embodiments, the method may include potting, heat shrinking, or molding the assembly obtained from the steps described above.

[0109] In some embodiments, the method includes (i) bringing the CNT-to-metal connector (optionally connected to the CNT member (directly or via a CNT connector pad)) and (ii) bringing the metal member into contact at an interface to form a joint of the assembly. In some embodiments, the CNT-to-metal connector may include graphene, and the method may include a solidification step (e.g., drying the graphene). Additionally or alternatively, the CNT-to-metal connector may include epoxy (e.g., metal-containing epoxy), and the method may include a curing step.

[0110] In some embodiments, the method includes soldering or brazing CNT material (of the CNT component of the CNT connector pad) to a CNT-to-metal connector or metal component. In some embodiments, the soldering or brazing is performed using a reactive metal foil (e.g., a reactive Al / Ni metal foil plated with a metal solder such as Sn solder).

[0111] In some embodiments, the method includes wetting the surface of the CNT material before the soldering or brazing step. In some embodiments, wetting the surface of the CNT material includes one or more of the following: (a) electroplating the surface of the CNT member with a metal (e.g., the metal includes one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W); (b) sputter coating the surface of the CNT member with a metal (e.g., the metal includes one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W); and (c) vapor deposition of a metal (e.g., the metal includes one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W). In some embodiments, the method includes providing a conductive metal-filled epoxy (e.g., Ag-filled epoxy) to the interface. In some embodiments, the method includes wrapping (or tying, including making knots) the joint with CNT fibers. In some embodiments, the method includes potting, heat-shrinking, or molding the assembly.

[0112] According to some embodiments, CNT fibers or films used in a method for producing an assembly (e.g., a CNT-to-metal assembly as described herein) may be prepared from the CNT materials described herein.

[0113] Exemplary Embodiments The following embodiments are provided as examples only, and are not limiting.

[0114] Embodiment 1. An assembly comprising a carbon nanotube (CNT) member connected to a metal member, wherein the CNT member comprises a CNT material comprising at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), and the CNT or CNT material exhibits one or more or all of the following properties: (a) the CNT material has an electrical conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m; (b) the CNT has an average aspect ratio of at least 1,000, at least 5,000, or at least 10,000; and (c) the CNT has an average G / D ratio of at least 1, at least 10, or at least 100.

[0115] Embodiment 2. The assembly according to Embodiment 1, wherein the CNT members are connected to a metal member via a CNT-to-metal connector, and the CNT-to-metal connector comprises a material selected from graphene, metal, and metal-containing epoxy.

[0116] Embodiment 3. The assembly according to Embodiment 1, wherein a CNT member is connected to a metal member via a CNT connector pad, the CNT connector pad comprises a CNT material containing at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), and the CNT or CNT material exhibits one or more or all of the following properties: (a) the CNT material has an conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m; (b) the CNT has an average aspect ratio of at least 1,000, at least 5,000, or at least 10,000; and (c) the CNT has an average G / D ratio of at least 1, at least 10, or at least 100.

[0117] Embodiment 4. The assembly according to Embodiment 3, wherein the CNT connector pad is connected to a metal member via a CNT-to-metal connector, and the CNT-to-metal connector comprises a material selected from graphene, metal, and metal-containing epoxy.

[0118] Embodiment 5. The assembly according to Embodiment 3, wherein the CNT connector pad consists of a single layer of aligned or unaligned CNT material having a thickness of 1 to 10 μm.

[0119] Embodiment 6. The assembly according to Embodiment 3, wherein the CNT connector pad is composed of multiple aligned layers of CNT material and has a thickness of 1 μm to 0.5 mm.

[0120] Embodiment 7. The assembly according to Embodiment 3, wherein the CNT connector pad is composed of multiple aligned layers of CNT material, the multiple layers include a first layer of the CNT material and a second layer of the CNT material, and the first layer and the second layer are arranged in different orientations relative to each other.

[0121] Embodiment 8. The assembly according to Embodiment 3, wherein the CNT connector pad is composed of multiple aligned layers of CNT material, the multiple layers comprising an outer layer of the CNT material and one or more intermediate layers of the CNT material, one or more of the intermediate layers being sputter-coated or electroplated with a thin metal layer, optionally being one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W, and optionally being selected from Cu, In, or Ni.

[0122] Embodiment 9. The CNT material of the CNT member has the following characteristics: (i) The CNT material contains less than 20% by weight, less than 10% by weight, or less than 5% by weight of non-sp2 hybridized carbon material, or the non-sp2 hybridized carbon material is not present in the CNT material; (ii) The CNT material contains less than 10% by weight, less than 5% by weight, or less than 2% by weight of metal particle impurities, or the metal particle impurities are not present in the CNT material; and (iii) The CNT material contains at least 1 g / cm³ 3 at least 1.2 g / cm³ 3 , or at least 1.4 g / cm³ 3 An assembly according to any one of embodiments 1 to 8, further indicating that it has a density of , one or more of the following:

[0123] Embodiment 10. The CNT material of the CNT connector pad has the following characteristics: (i) The CNT material contains less than 20% by weight, less than 10% by weight, or less than 5% by weight of non-sp2 hybridized carbon material, or the non-sp2 hybridized carbon material is not present in the CNT material; (ii) The CNT material contains less than 10% by weight, less than 5% by weight, or less than 2% by weight of metal particle impurities, or the metal particle impurities are not present in the CNT material; and (iii) The CNT material has at least 1 g / cm³ 3 at least 1.2 g / cm³ 3 , or at least 1.4 g / cm³ 3 An assembly according to any one of embodiments 3 to 8, further indicating that it has a density of , one or more of the following:

[0124] Embodiment 11. The assembly according to any one of the prior embodiments, wherein the CNT member is in a form selected from film, fiber, foam, and coating.

[0125] Embodiment 12. An assembly according to any one of the prior embodiments, wherein the metal component is selected from a metal matrix, metal wires, metal cables, ring terminals, circuit board terminals, quick disconnect terminals, spade terminals, hook terminals, snap plug terminals, battery terminals, battery terminal clamps, battery springs, grounding blocks, butt splices, wire ferrules, terminal blocks, compression lugs, set screw lugs, BNC (Bayonet Neill-Concelman) connectors, RCA (Radio Corporation of America) connectors, SMA (SubMiniature version A) connectors, and F-type connectors.

[0126] Embodiment 13. An assembly according to any one of the prior embodiments, wherein the CNT member is selected from display electrodes, touchscreen electrodes, energy harvesting electrodes, solar cell electrodes, battery electrodes, electrostatic dissipation elements, grounding elements, resistive heating elements, strain detection elements, chemical sensor elements, antenna radiating elements, antenna grounding surfaces, coaxial cable outer shields, coaxial cable inner conductors, smart sheathing for on-site wear monitoring, resistive elements for sensors, capacitive elements for sensors, inductive elements for sensors, biosensing elements for muscle activity, biosensing elements for nerve activity, muscle stimulation electrodes, nerve stimulation electrodes, DC power cables, DC transmission lines, AC power cables, A / C transmission lines, field emitters, transformer coils, DC motor coils, electronic textiles, transistors, conductors, capacitors, and inductors.

[0127] Embodiment 14. An assembly according to any one of the prior embodiments, wherein the assembly exhibits one or more of the following characteristics: (i) signal attenuation of 20 dB to 30 dB, 10 dB to 20 dB, or 5 dB to 10 dB; (ii) signal-to-noise ratio of 2:1 to 5:1, 5:1 to 20:1, or 20:1 to 100:1; (iii) phase shift of the signal entering the assembly less than pi / 12 rad, less than pi / 24 rad, or less than pi / 96 rad; and (iv) temperature difference compared to the steady-state temperature of the metal component less than 25 °C, less than 15 °C, or less than 5 °C.

[0128] Embodiment 15. A method for manufacturing an assembly described in any one of the prior embodiments, comprising bringing a CNT member and a metal member into contact at an interface to form a joint, further comprising one or more of the following steps: wrapping or tying the joint with CNT fibers or a film or foam; electroplating the surface of the CNT material of the CNT member with metal; sputter coating the surface of the CNT material of the CNT member with metal; wetting the surface of the CNT material of the CNT member before a soldering or brazing step; soldering or brazing the CNT material of the CNT member to the metal member; providing a conductive metal-filled epoxy at the interface; applying a reactive foil containing metal solder to the interface using one or more selected from pressure, electric current and heat; and potting, heat-shrinking or molding the assembly.

[0129] Embodiment 16. A method for manufacturing the assembly described in Embodiment 2, comprising bringing a CNT member and a CNT-to-metal connector into contact at an interface to form a joint, further comprising one or more of the following steps: wrapping or tying the joint with CNT fibers or film or foam; electroplating the surface of the CNT material of the CNT member with metal; sputter coating the surface of the CNT material of the CNT member with metal; wetting the surface of the CNT material of the CNT member before a soldering or brazing step; soldering or brazing the CNT material of the CNT member to the CNT-to-metal connector; providing a conductive metal-filled epoxy to the interface; applying a reactive foil containing metal solder to the interface using one or more selected from pressure, current and heat; and potting, heat-shrinking or molding the assembly.

[0130] Embodiment 17. The method according to Embodiment 15 or 16, wherein the metal is one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W, and optionally the metal is selected from Cu, In, or Ni.

[0131] Embodiment 18. A method for manufacturing an assembly according to any one of Embodiments 3 to 8, comprising bringing a CNT member and a CNT connector pad into contact at an interface, further comprising the following steps: connecting the CNT member to the CNT connector pad via capillary action by evaporating a solvent at the interface, wherein optionally the solvent is one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether); solvent welding the CNT connector pad to the CNT member using an acid; and mechanically joining the CNT connector pad to the CNT member.

[0132] Embodiment 19. The method according to Embodiment 18, further comprising bringing a CNT connector pad and a metal member into contact at an interface to form a joint of an assembly, further comprising one or more of the following steps: wrapping or tying the joint with CNT fibers or film or foam; electroplating the surface of the CNT material of the CNT connector pad with metal; sputter coating the surface of the CNT material of the CNT connector pad with metal; wetting the surface of the CNT material of the CNT connector pad before the soldering or brazing step; soldering or brazing the CNT material of the CNT connector pad to the metal member; providing a conductive metal-filled epoxy to the interface; applying a reactive foil containing metal solder to the interface using one or more selected from pressure, current and heat; and potting, heat-shrinking or molding the assembly.

[0133] Embodiment 20. The method according to Embodiment 19, wherein the metal is one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W, and optionally the metal is selected from Cu, In, or Ni.

[0134] Embodiment 21. A method for manufacturing an assembly according to any one of Embodiments 3 and 5 to 8, comprising providing a CNT connector pad on the surface of a metal member by wrapping or tying a pre-formed CNT film or foam around the metal member, wrapping or tying CNT fibers around the metal member, or directly forming a CNT film on the surface of the metal member from a fluid phase.

[0135] Embodiment 22. A method for producing an assembly according to any one of Embodiments 3 and 5-8, wherein (i) a pre-formed CNT film or CNT foam is loaded into a transfer sleeve, optionally including one or more of the following steps: (a) providing the CNT film or CNT foam around the support, wetting the inner surface of the transfer sleeve, inserting the support into the transfer sleeve, compressing the transfer sleeve over / around the support, and withdrawing the support from the transfer sleeve to obtain a sleeve loaded with the CNT film or CNT foam; or (b) the CNT film or CNT foam is directly transferred from the fluid phase to the inner surface of the transfer sleeve. A method comprising (i) loading, which includes (ii) preparing a CNT film or CNT foam in situ inside a transfer sleeve by forming a T-form, and (ii) transferring the CNT film or CNT foam from the transfer sleeve to a metal member, wherein the transfer optionally includes one or more of the following steps: wetting the surface of the metal member; inserting the metal member into the sleeve loaded with the CNT film or CNT foam; compressing the sleeve over / around the metal member; and withdrawing the sleeve from the metal member to obtain a metal member having a CNT connector pad made of CNT film or CNT foam.

[0136] Embodiment 23. The method according to any one of Embodiments 19 to 22, further comprising the steps of: promoting densification between the CNT connector pad and the metal member by evaporating a solvent at the interface between the CNT connector pad and the metal member to promote densification via capillary action, wherein optionally the solvent is one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether); applying pressure to the interface; applying electric current to the interface; and applying heat to the interface.

[0137] Embodiment 24. The method according to any one of Embodiments 21 to 23, further comprising: bringing a CNT member and a CNT connector pad into contact at an interface; and promoting the connection between a CNT member and a CNT connector pad by one or more of the following steps: evaporating a solvent at the interface between the CNT connector pad and the CNT member to promote densification via capillary action, wherein optionally the solvent is one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether); solvent welding the CNT connector pad to the CNT member using an acid; and mechanically joining the CNT connector pad to the CNT member.

[0138] Embodiment 25. An assembly comprising a carbon nanotube (CNT) member connected to a CNT connector pad, wherein each of the CNT member and the CNT connector pad independently comprises a CNT material comprising at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), and the CNT or CNT material exhibits one or more of the following properties: the CNT material has an conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m; the CNT has an average aspect ratio of at least 1,000, at least 5,000, or at least 10,000; and the CNT has an average G / D ratio of at least 1, at least 10, or at least 100.

[0139] Embodiment 26. An assembly comprising a metal member connected to a CNT connector pad, wherein the CNT connector pad comprises a CNT material comprising at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), and the CNTs or CNT material exhibit one or more or all of the following properties: the CNT material has a conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m; the CNTs have an average aspect ratio of at least 1,000, at least 5,000, or at least 10,000; and the CNTs have an average G / D ratio of at least 1, at least 10, or at least 100.

[0140] Embodiment 27. An assembly according to any one of Embodiments 1 to 14 and 26, or the method according to any one of Embodiments 15 to 24, wherein the metal member comprises one or more metals selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W. [Examples]

[0141] Example 1. Mechanical fixation Example 1a. Preparation of CNT film. A CNT film (approximately 4 μm thick) was prepared from CNT material using a doctor blade coating method according to the method described in U.S. Patent No. 11,111,146 (which is incorporated in whole by reference).

[0142] Example 1b. Preparation of an SMA connector for mechanical fixation to a CNT antenna. A CNT connector pad was formed by individually winding a CNT film, manufactured according to Example 1a, around the center pin and grounding feet of an SMA connector (SubMiniature version A connector), respectively, until the thickness reached approximately 100 μm around the connector element. The wound CNT film (CNT connector pad) was then exposed to acetone mist and pressure was applied to compress the wound film to a thickness of less than 70 μm. Evaporation of the acetone improved the adhesion of the film, strengthening the connection between the CNT connector pad and the SMA connector, for example. The SMA connector with the wound CNT film was mounted on the dielectric substrate of a CNT patch antenna so that the center pin of the SMA connector with the wound CNT film was in close contact with the radiating element, and the grounding feet of the SMA connector with the wound CNT film were in close contact with the grounding element. A fluorinated ethylene propylene (FEP) tape (50 μm thick) with silicone adhesive was applied over these areas to provide mechanical compression. The potting compound was applied to the tape to mechanically secure the connection area (Image c in Figure 5).

[0143] Example 2. Electroplating of copper pads A CNT power transmission line having a 2 mm wide trace and terminating at a CNT connector pad (5 mm in diameter) was laser-cut from a 4 μm thick CNT film prepared according to Example 1a. See Figure 3E. Therefore, the CNT connector pad was the region of the CNT member (CNT power transmission line).

[0144] Electroplating. Copper-plated CNT connector pads were prepared on a power line as follows. Droplets of electroplating solution (20% w / w copper sulfate (CuSO4) aqueous solution) were applied to each of the four CNT connector pads so that the CNT connector pads were covered with the electroplating solution. A DC power supply was connected to the CNT material of the power line via spring-loaded gold-plated connector pins, the contact surfaces of which had a diameter of 2 mm. A copper wire (18 American Wire Gauge, acting as the anode) was gently brought into contact with the top surface of the droplet while applying a DC voltage of 1.2 V in constant voltage mode (Figure 3E).

[0145] Example 3. Soldering Soldering between the copper-plated CNT connector pads prepared as described above and the resistor legs for contact resistance testing was achieved using lead-free tin solder and indium solder, as well as reactive indium foil (such as NanoFoil® from Indium Corporation, a reactive multilayer foil manufactured by alternately depositing nanoscale layers of Al and Ni). Soldering was applied using conventional techniques. NanoFoil® was activated using a hot tip of a nichrome wire heating element. Soldering with lead-free tin solder produced the solder droplets and contact angles shown in Figures 3A to 3D.

[0146] Example 4. Measurement of Resistance Measurement Setup - Method A. Two lead wires were soldered to either end of an electroplated Cu pad on two CNT films prepared in the same manner as in Example 2 above. Except that CNT films were used as the substrate instead of CNT transmission wires. The CNT films were connected to a 10Ω resistor via the electroplated Cu pads, and the resistor legs were soldered. Using a Keysight 34461A multimeter, a total series resistance of 11.38Ω was observed. Separately, a resistance of 10.33Ω was observed in the resistor. After subtracting the measured resistance of the CNT films, the remaining difference (due to the four contact resistances of the soldered wires and resistor legs on the electroplated Cu pads) was less than the measurement uncertainty of the multimeter. The negligible contact resistance demonstrates that the CNT connection provided good electrical contact without loss.

[0147] Measurement Setup - Method B. Two lead wires were wrapped with CNT film and mechanically joined to the two bare ends of the CNT fibers, as in Example 1a above. The other ends of the wrapped lead wires were electroplated and connected to a 10Ω resistor via soldered heat shrink tubing (Figure 5). Using a Keysight 34461A multimeter, a total series resistance of 12.48 Ω was observed. Separately, a resistance of 10.12 Ω was observed in the resistor. After subtracting the measured resistance of the CNT fibers, the remaining difference (attributed by the following four contact resistances: two contact resistances between the electroplated CNT fibers and the resistor legs, and two contact resistances between the mechanically joined CNT fibers and the lead wires wrapped with CNTs) was less than the measurement uncertainty of the multimeter. The negligible contact resistances demonstrate that the CNT connection provided good electrical contact without loss.

[0148] Example 5. Method using a transfer sleeve A transfer sleeve designed to mate with a 1mm x 1mm square metal pin having an exposed length of 5mm is used to certify the CNT connector pad on the metal pin. The internal dimensions of the transfer sleeve are 1.1mm x 1.1mm and its length is 3mm.

[0149] A pre-formed CNT film was wrapped around a PTFE support (rod) that had the same cross-sectional dimensions as the metal pin and was twice the length of the transfer sleeve. The CNT film was wrapped around the support so that it covered a length of 3 mm (corresponding to the inner length of the sleeve). See panel a in Figure 10.

[0150] Transfer of CNT film from support to sleeve: Wet the inner surface of the sleeve with water to facilitate the transfer of the CNT film from the support to the sleeve. Insert the support into the sleeve and compress the sleeve around the support to promote contact with the CNT film and the transfer of the CNT film from the support to the sleeve. Remove the sleeve, leaving the CNT film inside. Refer to panels b-c of Figure 10.

[0151] Transferring the CNT film from the sleeve to the metal pin: The film is transferred to the metal pin using a similar procedure. The metal pin is moistened with water to facilitate the transfer of the CNT film from the sleeve to the metal pin. The sleeve is fitted onto the metal pin (i.e., placed on top of it) and compressed around the metal pin to facilitate contact with the CNT film and the transfer of the CNT film from the sleeve to the metal pin. The sleeve is then removed from the metal pin. The metal pin is finally covered with the CNT film and can function as a CNT connector pad on the metal pin. See panels d-e of Figure 10.

[0152] Optionally, take further steps (e.g., wetting with water, wetting with acetone, heating, or compressing) to ensure that the CNT film (CNT connector pad) remains securely in place on the metal pin until it is connected to the CNT member. See panel f in Figure 10.

Claims

1. An assembly comprising a carbon nanotube (CNT) member connected to a metal member, wherein the CNT member comprises a CNT material containing at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), and the CNT or CNT material has the following properties: (a) The CNT material has an electrical conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m. (b) The CNT has an average aspect ratio of at least 1000, at least 5000, or at least 10,000, and (c) An assembly that exhibits one or more of the following: the CNT has an average G / D ratio of at least 1, at least 10, or at least 100.

2. The assembly according to claim 1, wherein the CNT member is connected to the metal member via a CNT-to-metal connector, and the CNT-to-metal connector comprises a material selected from graphene, metal, and metal-containing epoxy.

3. The CNT member is connected to the metal member via a CNT connector pad, and the CNT connector pad comprises a CNT material containing at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), and the CNT or CNT material has the following properties: (a) The CNT material has an electrical conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m. (b) The CNT has an average aspect ratio of at least 1000, at least 5000, or at least 10,000, and (c) The assembly according to claim 1, wherein one or more of the following are represented: the CNT has an average G / D ratio of at least 1, at least 10, or at least 100.

4. The assembly according to claim 3, wherein the CNT connector pad is connected to the metal member via a CNT-to-metal connector, and the CNT-to-metal connector comprises a material selected from graphene, metal, and metal-containing epoxy.

5. The assembly according to claim 3, wherein the CNT connector pad is composed of a single layer of aligned or unaligned CNT material having a thickness of 1 to 10 μm.

6. The assembly according to claim 3, wherein the CNT connector pad is composed of multiple aligned layers of CNT material and has a thickness of 1 μm to 0.5 mm.

7. The assembly according to claim 3, wherein the CNT connector pad is composed of a plurality of aligned layers of CNT material, the plurality of layers including a first layer of the CNT material and a second layer of the CNT material, and the first layer and the second layer are arranged in different orientations relative to each other.

8. The assembly according to claim 3, wherein the CNT connector pad is composed of a plurality of aligned layers of CNT material, the plurality of layers comprising an outer layer of the CNT material and one or more intermediate layers of the CNT material, one or more of the intermediate layers being sputter-coated or electroplated with a thin metal layer, optionally the metal being one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W, and optionally the metal being selected from Cu, In, or Ni.

9. The CNT material of the CNT member has the following characteristics: (i) The CNT material contains less than 20% by weight, less than 10% by weight, or less than 5% by weight of non-sp2 hybridized carbon material, or the non-sp2 hybridized carbon material is not present in the CNT material. (ii) The CNT material contains less than 10% by weight, less than 5% by weight, or less than 2% by weight of metal particle impurities, or metal particle impurities are not present in the CNT material, and (iii) The CNT material contains at least 1 g / cm³ ３ at least 1.2 g / cm³ ３ , or at least 1.4 g / cm³ ３ The assembly according to claim 3, further relating to having a density of, one or more of the following:

10. The CNT material of the CNT connector pad has the following characteristics: (i) The CNT material contains less than 20% by weight, less than 10% by weight, or less than 5% by weight of non-sp2 hybridized carbon material, or the non-sp2 hybridized carbon material is not present in the CNT material. (ii) The CNT material contains less than 10% by weight, less than 5% by weight, or less than 2% by weight of metal particle impurities, or metal particle impurities are not present in the CNT material, and (iii) The CNT material contains at least 1 g / cm³ ３ at least 1.2 g / cm³ ３ , or at least 1.4 g / cm³ ３ The assembly according to claim 3, further relating to having a density of, one or more of the following:

11. The assembly according to claim 3, wherein the CNT member is in a form selected from film, fiber, foam, and coating.

12. The aforementioned metal components include metal matrices, metal wires, metal cables, ring terminals, circuit board terminals, quick disconnect terminals, spade terminals, hook terminals, snap plug terminals, battery terminals, battery terminal clamps, battery springs, grounding blocks, butt splices, wire ferrules, terminal blocks, compression lugs, set screw lugs, BNC (Bayonet Neill-Concelman) connectors, TNC (Thrreaded Neill-Concelman) connectors, RCA (Radio Corporation of America) connectors, SMA (SubMiniature version A) connectors, SMC (SubMiniature version C) connectors, FFC (Flat Flexible Cable) connectors, and FPC (Flexible Printed) connectors. The assembly according to claim 3, which is selected from a Circuit connector, a DIN (Deutsches Institute for Normung) connector, and an F-type connector.

13. The assembly according to claim 3, wherein the CNT member is selected from display electrodes, touchscreen electrodes, energy harvesting electrodes, solar cell electrodes, battery electrodes, electrostatic dissipation elements, grounding elements, resistive heating elements, strain detection elements, chemical sensor elements, antenna radiating elements, antenna grounding surfaces, coaxial cable outer shields, coaxial cable inner conductors, smart sheathing for on-site monitoring of wear, sensor resistive elements, sensor capacitive elements, sensor inductive elements, muscle activity biosensing elements, nerve activity biosensing elements, muscle stimulation electrodes, nerve stimulation electrodes, DC power cables, DC transmission lines, AC power cables, A / C transmission lines, field emitters, transformer coils, DC motor coils, electronic textiles, resistors, transistors, conductors, capacitors, and inductors.

14. The assembly has the following characteristics: Signal attenuation of 20 dB to 30 dB, 10 dB to 20 dB, or 5 dB to 10 dB. Signal-to-noise ratios of 2:1 to 5:1, 5:1 to 20:1, or 20:1 to 100:

1. Phase shift for signals entering the assembly less than pi / 12rad, less than pi / 24rad, or less than pi / 96rad, and The assembly according to claim 3, wherein one or more of the following are observed: a temperature difference compared to the steady-state temperature of the metal member, which is less than 25°C, less than 15°C, or less than 5°C.

15. A method for manufacturing the assembly described in claim 1, comprising bringing the CNT member and the metal member into contact at an interface to form a joint, the following steps: Wrapping or tying the joint with CNT fibers, film, or foam, The surface of the CNT material of the CNT member is electroplated with metal. The surface of the CNT material of the CNT member is sputter-coated with metal. Before the soldering or brazing step, wet the surface of the CNT material of the CNT member. Soldering or brazing the CNT material of the CNT member to the metal member, To provide a conductive metal-filled epoxy at the interface, Applying a reactive foil containing metal solder to the interface using one or more selected from pressure, current, and heat, and A method further comprising one or more or all of the following: potting, heat shrinking, or molding the assembly.

16. The method according to claim 15, wherein the metal is one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W, and optionally the metal is selected from Cu, In, or Ni.

17. A method for manufacturing the assembly described in claim 2, comprising bringing the CNT member and the CNT-to-metal connector into contact at an interface to form a joint, the following steps: Wrapping or tying the joint with CNT fibers, film, or foam, The surface of the CNT material of the CNT member is electroplated with metal. The surface of the CNT material of the CNT member is sputter-coated with metal. Before the soldering or brazing step, wet the surface of the CNT material of the CNT member. Soldering or brazing the CNT material of the CNT member to the CNT-to-metal connector. To provide a conductive metal-filled epoxy at the interface, Applying a reactive foil containing metal solder to the interface using one or more selected from pressure, current, and heat, and A method further comprising one or more or all of the following: potting, heat shrinking, or molding the assembly.

18. The method according to claim 17, wherein the metal is one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W, and optionally the metal is selected from Cu, In, or Ni.

19. A method for manufacturing the assembly described in claim 3, comprising bringing the CNT member and the CNT connector pad into contact at an interface, the following steps: The process involves evaporating the solvent at the interface to connect the CNT member to the CNT connector pad via capillary action, wherein the solvent is optionally one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether). Solvent welding the CNT connector pad to the CNT member using an acid, and A method further comprising one or more of the following: mechanically joining the CNT connector pad to the CNT member.

20. The process further includes bringing the CNT connector pad and the metal member into contact at the interface to form a joint of the assembly, and the following steps: Wrapping or tying the joint with CNT fibers, film, or foam, The surface of the CNT material of the CNT connector pad is electroplated with metal. The surface of the CNT material of the CNT connector pad is sputtered with metal. Before the soldering or brazing step, wet the surface of the CNT material of the CNT connector pad. Soldering or brazing the CNT material of the CNT connector pad to the metal member, To provide a conductive metal-filled epoxy at the interface, Applying a reactive foil containing metal solder to the interface using one or more selected from pressure, current, and heat, and The method according to claim 19, further comprising one or more of the following: potting, heat shrinking, or molding the assembly.

21. The method according to claim 20, wherein the metal is one or more selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W, and optionally the metal is selected from Cu, In, or Ni.

22. A method for manufacturing the assembly described in claim 3, Wrapping or tying a pre-formed CNT film or foam around a metal component, Wrapping or tying CNT fibers around the metal member, A method comprising providing a CNT connector pad on the surface of a metal member by directly forming a CNT film on the surface of the metal member from a fluid phase.

23. A method for manufacturing the assembly described in claim 3, (i) Loading a pre-formed CNT film or CNT foam into a transfer sleeve, optionally comprising one or more of the following steps: (a) providing the CNT film or CNT foam around a support, wetting the inner surface of the transfer sleeve, inserting the support into the transfer sleeve, compressing the transfer sleeve on / around the support, and withdrawing the support from the transfer sleeve to obtain a sleeve loaded with the CNT film or CNT foam, or (b) preparing the CNT film or CNT foam in situ inside the transfer sleeve by forming the CNT film or CNT foam directly on the inner surface of the transfer sleeve from a fluid phase. (ii) A method for transferring the CNT film or CNT foam from the transfer sleeve to a metal member, wherein the transfer optionally includes one or more of the following steps: wetting the surface of the metal member; inserting the metal member into the sleeve loaded with the CNT film or CNT foam; compressing the sleeve over / around the metal member; and withdrawing the sleeve from the metal member to obtain the metal member having a CNT connector pad made of the CNT film or CNT foam.

24. The following steps: The process involves evaporating a solvent at the interface between the CNT connector pad and the metal member to promote densification via capillary action, wherein the solvent is optionally one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether). Applying pressure to the aforementioned interface, Applying current to the interface, and The method according to claim 20, further comprising facilitating the connection between the CNT connector pad and the metal member by one or more of the following: applying heat to the interface.

25. The CNT member and the CNT connector pad are brought into contact at the interface, and the following steps are taken: The method involves evaporating a solvent at the interface between the CNT connector pad and the CNT member to promote densification via capillary action, wherein the solvent is optionally one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether). Solvent welding the CNT connector pad to the CNT member using an acid, and The method according to claim 22, further comprising facilitating connection between the CNT member and the CNT connector pad by mechanically joining the CNT connector pad to the CNT member, by one or more of the above.

26. The CNT member and the CNT connector pad are brought into contact at the interface, and the following steps are taken: The method involves evaporating a solvent at the interface between the CNT connector pad and the CNT member to promote densification via capillary action, wherein the solvent is optionally one or more selected from water, acetone, methyl ethyl ketone, diethyl ether, chloroform, n-hexane, ethanol, ethylene glycol, xylene, toluene, THF (tetrahydrofuran), NMP (N-methyl-2-pyrrolidone), and HFE (hydrofluoroether). Solvent welding the CNT connector pad to the CNT member using an acid, and The method according to claim 23, further comprising facilitating connection between the CNT member and the CNT connector pad by mechanically joining the CNT connector pad to the CNT member, by one or more of the above.

27. An assembly comprising a carbon nanotube (CNT) member connected to a CNT connector pad, wherein each of the CNT member and the CNT connector pad independently comprises a CNT material containing at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), and the CNT or CNT material has the following properties: The CNT material has an electrical conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m. The CNT has an average aspect ratio of at least 1000, at least 5000, or at least 10,000, and An assembly in which the CNT has one or more or all of the following: at least 1, at least 10, or at least 100 average G / D ratios.

28. An assembly comprising a metal member connected to a CNT connector pad, wherein the CNT connector pad comprises a CNT material containing at least 90% by weight, at least 95% by weight, or at least 99% by weight of carbon nanotubes (CNTs), and the CNT or CNT material has the following properties: The CNT material has an electrical conductivity of at least 1 MS / m, at least 5 MS / m, or at least 10 MS / m. The CNT has an average aspect ratio of at least 1000, at least 5000, or at least 10,000, and An assembly in which the CNT has one or more or all of the following: at least 1, at least 10, or at least 100 average G / D ratios.

29. The assembly according to claim 1, wherein the metal member comprises one or more metals selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W.

30. The assembly according to claim 2, wherein the metal member comprises one or more metals selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W.

31. The assembly according to claim 3, wherein the metal member comprises one or more metals selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W.

32. The method according to claim 15, wherein the metal member comprises one or more metals selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W.

33. The method according to claim 20, wherein the metal member comprises one or more metals selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W.

34. The method according to claim 22, wherein the metal member comprises one or more metals selected from Cu, In, Ni, Ag, Au, Sn, Al, Zn, Pt, Pd, Pb, Mo, Mg, Rh, and W.

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