Field of invention

[001] The subject matter of the present invention relates to a low resistance nanostructured electrical conductor with a combination of a first set of nanostructured metal nanoparticles that are dispersed in a second set of metal nanoparticles. The present invention also provides a process for the preparation of the low resistance nanostructured electrical conductor.

Background of the invention

[002] Low resistance electrical conductors are of great fundamental and technological importance and can have far-reaching impact on society and environment. Superconductors are such conductors, which can not only carry electrical current with no measurable energy dissipation, but are also robust at high magnetic fields, having applications in medical diagnostics, and research sectors. However, under ambient pressure, the known superconductors carry dissipation-less supercurrent only at low temperatures, which severely limits their large-scale applications. The low superconducting transition temperature in conventional superconductors is due to small phonon energy (or Debye frequency), which increases to close to 200 Kelvin in high Tc ceramics, although a microscopic understanding of the latter is not available. It has been suggested that some of the plasmonic nanostructures can host high temperature superconductivity, owing to large plasmon frequency (~ 2 eV) in metals.

[003] In a publication titled "Evidence for Superconductivity at Ambient Temperature and Pressure in Nanostructures" by Thapa & Pandey (arXiv: 1807.08572 [cond-mat.supr-con]) it is disclosed that clusters of silver nanoparticles (diameter ~ 1 nm) that are dispersed in gold matrix can exhibit ambient pressure superconducting state at or above room temperature. While the microscopic mechanism of such a superconducting transition is currently being investigated, the superconducting nanostructures has to be realized in the film and the pellet forms, so that they can be employed in various applications, such as interconnects in electronics, cables in electrical appliances, coils in high field magnets, shielding against electromagnetic interference, and many other domestic, technological, and strategic applications. Unprotected film of nanostructures are prone to rapid degradation due to adverse effects of oxygen and/or moisture present in the ambient conditions.

[004] In known nanostructured conductors with at least two components, the resistivity of the nanostructured conductor is typically in excess of or comparable to the resistivity of the individual component materials.

Objects of the present invention

[005] The primary object of the present invention is to provide a low resistance nanostructured electrical conductor with a combination of a first set of nanostructured metal nanoparticles that are dispersed in a second set of metal nanoparticles.

[006] An object of the present invention is to provide a process for the preparation of the low resistance nanostructured electrical conductor with a combination of a first set of nanostructured metal nanoparticles that are dispersed in a second set of metal nanoparticles.

[007] Another object of the present invention is to provide the low resistance nanostructured electrical conductor, where electrical resistivity of the nanostructured conductor is lower than the individual resistivities of the first and second sets of metal nanoparticles.

[008] Yet another object of the present invention is to provide a process for the preparation of the low resistance nanostructured electrical conductor. Summary of the present invention

[009] A nanostructured electrical conductor is provided comprising a first set of metal nanoparticles with diameters in the range of about 0.3 to 2.5 nanometers are dispersed in a second set of metal particles, to form a low resistance nanostructured conductor. The present invention also provides a process for the preparation of the nanostructured conductor exhibiting a very low resistance. These conductors are composed of nanoparticles of metal (e.g. silver) dispersed in another metallic matrix (e.g. gold), and their electrical resistivity is three decades or more below that of conventional highly conducting metals, such as gold, copper or silver. The low resistance of these conductors can maintained up to 1000 K, depending on the composition, and under operating pressure.

Brief description of the drawings

[010] FIG. 1(a) is an image of a transmission electron micrograph (TEM) of Gold(Au)-Silver(Ag) nanoconductor.

[Oil] FIG. 1(b) is a selected area electron diffraction (SAED) pattern of Au-Ag nanoconductor.

[012] FIG. 1(c) is an image of a high resolution transmission electron microscopy (HRTEM) of Au-Ag nanoconductor.

[013] FIG. 1(d) and (e) are images of high annular aperture dark field imaging (HAADF) and elemental mapping of Au-Ag nanoconductor.

[014] FIG. 2 is an optical micrograph of the nanoconductor as an exemplary nanocluster film, on a van der pau lead geometry.

[015] FIG. 3 shows a transition to the low resistance state in the exemplary nanocluster film.

[016] FIG. 4 demonstrates that the low resistance of the exemplary film is about six orders of magnitude below that of the normal metallic state of individual components. [017] FIG. 5 shows the current voltage characteristics of the exemplary nanoconductor film in the higher (normal) and lower resistance states.

[018] FIG. 6 depicts the effect of encapsulation of the nanoconductor film of the present invention.

[019] FIG. 7 depicts the emergence of diamagnetic screening property of the exemplary nanoconductor film at the onset of the low resistance state.

[020] FIG. 8 shows the emergence of diamagnetic screening property as the nanoconductor film is cooled.

[021] FIG. 9 shows the emergence of diamagnetic screening property as the nanoconductor film is cooled below a certain temperature

[022] FIG. 10 shows the screening of optical frequencies of the exemplary nanoconductor film.

Detailed description of the invention

[023] The present invention provides a low resistance nanostructured electrical conductor with combination of sets of metal nanoparticles.

[024] The nanostructured electrical conductor comprises, a first set of metal nanoparticles with diameters in the range of 0.3 to 2.5 nanometers are dispersed in a second set of metal nanoparticles having diameter in the range of about 8-12 nm, to form the low resistance nanostructured conductor. The low resistance and magnetic properties arise exclusively from the sizing of the first set of nanoparticles, their loading levels into the second material as well as factors such as spatial variations in the loading density. However, it is significant to note that size of the second set of metal particles is variable do not have a direct bearing on the formation of the nanostructured electrical conductor. In other words, the second set of nanoparticles can be a metal other than of nanoparticles.

[025] The present invention also provides a process for the preparation of the nanostructured electrical conductor and the protection of this conductor from environmental effects. The process which is an encapsulation process leads to an excellent protection against oxygen and moisture by overlaying the conductor with a layer of second substance that prevents direct contact between the conductor and the surroundings.

[026] In an aspect of the present invention, the nanostructured electrical conductor is formed from combination of the first and second set of metal nanoparticles, which are selected from a group of noble metals consisting of gold, silver and copper.

[027] In another aspect of the present invention, the electrical resistivity of the nanostructured electrical conductor is lower than the individual resistivities of the first and second set of metal nanoparticles.

[028] In yet another aspect of the present invention, volume diamagnetism of the nanostructured electrical conductor is greater than the individual volume diamagnetisms of first and second set of metal nanoparticles, in their normal states.

[029] In yet another exemplary aspect, in the present disclosure, the nanostructured electrical conductor is formed from a combination of metal nanoparticles.

[030] Accordingly, the nanostructured electrical conductor of the present invention, comprises, a first set of metal nanoparticles with diameters in the range of 0.3 to 2.5 nanometers are dispersed in a second set of metal nanoparticles, to form a low resistance nanostructured conductor.

[031] The first and second set of metal nanoparticles are selected from a group of noble metals consisting of gold, silver, manganese, platinum, palladium, aluminum, zinc and copper.

[032] In the present invention, as an exemplary embodiment, a combination or a set of silver (Ag)-gold (Au) nanoparticles, as first and second sets of metal nanoparticles, are used to form the the nanostructured electrical conductor that exhibits a low resistivity. However, it is within purview of the invention, to form a suitable nanostructured electrical conductor, by using different combinations of metal nanoparticles selected from materials such as copper and gold etc. In other cases, metals are favourably chosen to ensure a Volta potential difference between the two participants.

[033] An encapsulation layer is preferably is used to encapsulate or cover the nanostructured electrical conductor, so as to cover the active areas the nanostructured electrical conductor. The encapsulation layer typically serves as an oxygen and water diffusion barrier protecting the sensitive nanostructured electrical conductor. The encapsulation layer is also disposed to effectively reduce gas and liquid molecules permeating through the nanostructured electrical conductor, thereby extending the life of the nanostructured electrical conductor. The encapsulation layer is thus any layer that exhibits adhesion to the low resistance conductor, while also exhibiting a tendency to exclude oxygen.

[034] The encapsulation layer, in an exemplary aspect, for the nanostructured electrical conductor, is formed from an organic compound, which is preferably an epoxy resin, a polyacrylate, poly aniline or a paraffinic gel or a combination these compounds. The preferred material for the encapsulation layer can also be selected from materials such as, polycarbonate, or polyimide, and cross linked small molecules. The preferred material for the encapsulation layer further includes metals, organo-metallic compounds and oxides of metals such as copper, oxides of aluminium and tin oxide as well as certain metal salts such as zinc- acetate-oleate. The polymer encapsulation layer protects underlying nanostructured electrical conductor from unwanted oxidation.

[035] The nanostructured electrical conductor of the present invention can be formed into desired structures or members, such as a film, a wire and a pellet or any other suitable structures. These structures may be favourably used in a variety of possible applications as shields, current, voltage or energy carriers, signal and data transfer between two points, magnetic field generators etc.

[036] In yet another aspect of the present invention, substrate mounted films are prepared by depositing nanostructured electrical conductor onto a substrate. The second conductive material is subsequently overgrown onto the nanoparticles of the first, giving rise to a low resistance conductor film.

[037] In another aspect of the present invention, pellets are prepared by the deposition of either preformed architectures onto a substrate or else deposition of components that may or may not be in a low resistance state by themselves but allow access to a low resistant state below a certain temperature upon assembly. In an exemplary aspect, nanoparticles are agglomerated to lead to a pellet that is subsequently shaped to the desired form by mechanical pressing.

[038] Pellets are also prepared by agglomerating nanoparticles of two conductive materials, giving rise to a low resistance pellet. In an exemplary aspect, a conductive material is first coated on top of the nanoparticles of a second material. Low resistance pellets with enhanced diamagnetic properties are then prepared by forcing the agglomeration of the resultant core/shell particles to form a pellet.

[039] Low resistance regions of a pellet are coupled to each other by a conductor that may or may not be one of the ingredients of the low resistance regions. In a related implementation, the third material is an organic molecule capable of showing conductivity in films and assemblies. [040] In yet another aspect of the present invention, wires are prepared by the deposition of either preformed architectures onto a substrate wire or else deposition of components that may or may not be superconducting in themselves but form the low resistance conductor upon assembly. In an exemplary aspect, this process involves the deposition of low resistance conductor nanoparticles onto an elongated substrate. Post deposition, the substrate and deposited material together comprise a wire or else are coupled and/or packaged in to form a wire. In another implementation, nanoparticles are agglomerated to lead to a pellet that is subsequently shaped to form a film by mechanical pressing. Wires are also prepared by depositing nanoparticles of a conductive material onto an elongated substrate. The second conductive material is subsequently overgrown onto the nanoparticles of the first, giving rise to a low resistance film over the elongated substrate.

[041] In yet another aspect, patches of a low resistance conductor that are small in dimension are deposited onto a substrate. Subsequently, these are filled in by a third material. In a related implementation, the third material is an organic molecule capable of showing conductivity in films and assemblies.

[042] The preferred embodiments of the nanostructured electrical conductor of the present invention, which is exemplarily formed as a thin member, such as a film or a slab, preferably of a micron size, are now described, by initially referring to FIGs. l(a)-(e).

[043] In this aspect, the structural characteristics of the film are demonstrated by casting the film directly onto a graphite coated copper grid. Themis Titan transmission electron microscope (TEM) (300 kV) is used to collect data of the film. FIG.1(a), which is an exemplary low resolution TEM image of the nanostructured electrical conductor (film), comprises a first set of nanoparticles of silver (Ag), with a preferred diameter in the range of 0.3-2 nm that are disposed or embedded into a second set of nanoparticles of gold (Au) that shows a diameter of about 8- 12 nm.

[044] Now, lattice parameters of the two sets of metal nanoparticles viz., Ag and Au of the nanostructured electrical conductor (film) are now described, by referring to the crystallographic characteristics as shown in

FIGs. 1(b) and 1(c).

[045] As it can be seen from FIG.1(b), the nanoparticles of the nanostructured electrical conductor (film) demonstrate a selected area electron diffraction (SAED) pattern that agrees well with the patterns that are typically observed, in the case of individual nanometal particles - Au and Ag. It is to be noted in FIG.1(b) that the most of the significant planes are marked. These correspond to the standard lattice planes of gold and silver metals. The positions of these reflections are identical to the values observed in bulk samples and therefore suggest an overall retention of gold and silver lattice structure into the low resistance conductor material. In this pattern, forbidden reflections at 0.37 nm are also observed, which are attributed to the presence of twinned or otherwise defective nanoparticles. This attribute provides an indication that the lattice parameters of the two metals are conserved at the nanoscale. These results are also further corroborated in the high resolution TEM (HRTEM) image as shown in FIG.1(c), where both single and poly crystalline particles are present within the plurality of nanoparticles.

[046] The embedding of the metal nanoparticles in the nanostructured electrical conductor (film), is shown in FIG. 1(d) and FIG. 1(e), which evidences the embedding of Ag nanoparticles into an Au matrix. It is also seen the presence of a small number of individual free Ag particles in the nanostructured electrical conductor (film). A photograph of the film is shown in FIG. 2. [047] The preferred embodiments of the electrical resistivity of the nanostructured conductor of the present claimed invention, are now described by referring to FIG. 3 and FIG. 4.

[048] FIG. 3 shows a typical transition to the low resistance state in the nanocluster film, where the nanocluster density is such that the transition occurred at 272.8 K. This manifests itself in a nominally large resistance that is observed initially at higher temperatures. Subsequently, the resistance drops sharply below a certain temperature. Here this is shown on a logarithmic plot. The drop corresponds to an over of order of magnitude fall.

[049] Whereas, FIG. 4 demonstrates that the low resistance state of the nanocluster film (Ag-Au nanostructured electrical conductor), is nearly six orders of magnitude below that of the normal metallic state. The electrical resistivity of the nanocluster film in the low resistance state is at least three orders of magnitude smaller than the specific resistivity of noble metals, such as gold, silver and copper.

[050] FIG. 5 shows the current-voltage characteristics of an exemplary film below and above the transition temperature to a low resistance state. As evident, below the transition temperature, viz. in the low resistance state, the current-voltage characteristics are almost flat, consistent with a very low resistance. This corresponds to a very small, almost immesurable drop in voltage being observable across a pair of contacts when a current is forced through the film through the current contacts.

[051] Accordingly, the above-mentioned preferred embodiments, establish the fact that the electrical resistivity of the nanostructured conductor of the present invention, is lower than the individual resistivities of the first and second set of metal nanoparticles. In particular, the measured film resistivity in the low resistance state is as low as 10 ¹² Ohm-m or lower as opposed to the resistivity of gold and silver metals (~10 ⁸ Ohm-m)

[052] The diamagnetic characteristics of the nanostructured conductor of the present invention are now described. The nanostructured conductor of the present invention, exhibits a volume diamagnetism that is greater than the individual volume diamagnetism of the first and second set of metal nanoparticles, in their normal states.

[053] Accordingly, the present invention also provides an electromagnetic shield, that exhibits diamagnetism, comprising, the nanostructured electrical conductor that is formed from the dispersal of the first set of metal nanoparticles with diameters in the range of 0.3 to 2.5 nanometers in the second set of metal nanoparticles of about 10 nm diameter. The nanostructured electrical conductor is encapsulated by the encapsulating layer. The encapsulated nanostructured electrical conductor is disposed on a substrate. The shield thus formed can obstruct the flow of electromagnetic radiation and fields between two points in space. The substrate for this purpose is preferably glass or a metal. The substrate can also be made from polymer materials and an organic polymer material such as polystyrene. The material for the substrate can also be an inorganic solid material such as a borosilicate glass or a sapphire.

[054] The electromagnetic shield that is provided with the nanostructured electrical conductor, exhibits diamagnetism and repels or screens the external magnetic fields (up to the critical field) and the electromagnetic radiation. Beyond the critical field, the electromagnetic shield breaks down. Shielding property may be restored by either lowering the temperature of the shield or else employing it at a reduced field. This property can be exploited in electromagnetically shielding of any volume that is encapsulated by the nanostructured electrical conductor, as exemplarily shown in FIG.6. FIG.6 demonstrates diamagnetic screening in the superconducting phase in the nanocluster films (exemplary nanostructured electrical conductor). The mutual inductance drops approximately 1% at the transition, indicating that the screening property is connected to the low-resistance state.

[055] In this exemplary aspect, the nanostructured electrical conductor is positioned between a source of electromagnetic radiation and an object to be shielded. The nanostructured electrical conductor expels magnetic fields by virtue of its diamagnetism and also has a very limited penetration depth for electric fields due to its high electrical conductivity. As a result, the nanostructured electrical conductor acts as broadband shields for electromagnetic radiation and is efficacious over both long and short wavelengths of electromagnetic energy.

[056] Exemplary aspects of electromagnetic expulsion are shown in FIG. 7 and FIG. 8. As shown here, below a certain temperature, a film of the material expels electromagnetic fields, and greatly shields a second sense coil from magnetic fields being generated at a source coil. As shown in FIG. 7, the shielding effect in this example occurs at ~192 K.

[057] A similar shielding is operational at optical frequencies, whereby films of this material under different conditions attenuate light, as shown in FIG. 9. This is indicated by the reduced, non-100% optical transmission through the film.

[058] In another exemplary aspect, a source coil with 1 mA current at 43 kHz is placed over the nanostructured electrical conductor (film). A sense coil is placed 1.5 mm below the assembly in order to detect the presence of leaked electromagnetic radiation from the first coil. It is found that upon the transition to the low resistance state in the system, the coupling between the source and sense coils decreases. This suggests the ability of these class of conductors to efficiently act as electromagnetic shields. In contrast, a typical metal such as gold enables a significantly stronger coupling between the two coils. [059] Now, the preferred embodiments relating to the process steps for the preparation of the nanostructured electrical conductor as a thin film are described. In this process nanostructured electrical conductor nanostructures is deposited on the substrate. Thereafter, One or more of chemical, thermal, electrical or electromagnetic treatments at varied pressures are used to remove surfactant molecules from the deposit. These steps are repeated to obtain the desired thickness of nanostructured low resistance electrical conductor as a thin film. Alternatively, nanostructured electrical conductor as a thin film may also be obtained by agglomerating nanostructured electrical conductors as a thin film and subsequently pressing the agglomerates into films. Fillers such as metals or conducting organic molecules or doped semiconductors may be employed to increase inter grain connectivity or robustness. Films may be subsequently encapsulated to protect these from environmental damage using the procedures described.

[060] Now, the preferred embodiments relating to the process steps for the preparation of the nanostructured electrical conductor as a wire are described. In this process wires are prepared by favorably depositing nanostructured electrical conductors on elongated substrate. These could be cylindrical or strips.

[061] Subsequently, the usual procedures involved in film making are implemented as described above. It is further possible to combine multiple such films into a single bundle to produce a high gauge wire.

[062] Alternatively, it is possible to prepare nanostructure aggregates and further shape such aggregates into a wire by pressing.

[063] The process steps involved in the formation of a low resistance conductor or an electromagnetic shield essentially involve the incorporation of a plurality of nanoparticles into a second metal. Subsequent disposal onto a desired substrate as well as potential encapsulation enhance utility and applicability of the low resistance conductor.

[064] Accordingly, in the present invention, the nanostructured electrical conductor comprises, the first set of metal nanoparticles with diameters in the range of 0.3 to 2.5 nanometers are dispersed in the set of metal particles, to form the low resistance nanostructured conductor. The first set of nanoparticles and the second set of metal particles are selected from a group of noble metals consisting of gold, silver, manganese, platinum, palladium, aluminum, zinc and copper.

[065] In yet another aspect of the present invention, the low resistance nanostructured conductor includes the encapsulation layer, where the encapsulation layer is formed from the organic compound preferably an epoxy resin, a polyacrylate, poly aniline or a paraffinic gel or a combination thereof. The encapsulation layer can also be formed from materials such as copper, oxides of aluminium and tin oxide and zinc- acetate-oleate.

[066] It is also an aspect of the present invention, where the low resistance nanostructured conductor is a film, a wire and a pellet.

[067] In another aspect of the present invention, the electrical resistivity of the low resistance nanostructured conductor is between zero and the individual resistivities of the first set of metal nanoparticles and the second set of metals in their bulk states. The low resistance nanostructured conductor also exhibits a volume diamagnetism between - 1 (SI) and the individual volume diamagnetism of the first set of metal nanoparticles and the second set of metal particles, in their normal states.

[068] The present invention also provides the electromagnetic shield comprising : the low resistance nanostructured conductor and the substrate, where the material for the substrate is selected from glass, metal, organic polymer or an oxide such as aluminium oxide. [069] The preferred embodiments of the present invention are further described in the form of the following illustrating examples. However, these Examples should not be construed as limiting the scope of the claimed invention, since these examples illustrate the working of the invention.

Example 1: (Preparation of nanostructured electrical conductor)

[070] Aqueous solutions of 0.1M hexadecyltrimethylammonium bromide (10 ml_), 0.1M NaOH(0.1 ml), 1M ammonium bromide(l ml_), 0.1M potassium iodide (40 pL) and 1 mM silver nitrate(5 ml_) are mixed. The mixture is continuously stirred at 84 RCF till slight cloudiness appears, which is followed by the addition of 2 ml_ of 0.1M aqueous solution of sodium borohydride to produce the silver nanoparticles. Then 800 pl_ of ImM aqueous solution hydrogen tetrachloroaurate (III) trihydrate is added to the silver nanoparticles followed by 3 ml_ of propan-2-ol. The resulting solution and acetone are mixed in the ratio 1 : 1 by volume and centrifuged for 3-4 min at 4100 RCF. After centrifugation the supernatant is disposed off and the precipitate is dried in vacuum. The dry precipitate is dissolved in chloroform to obtain the nanostructured electrical conductor of Ag and Au. The resultant conductors are formed from agglomerated particles typically 8-12 nm in diameter. The agglomeration process however changes the size and connectivity of the resultant conductor. This process has been used to deposit films such as the ones as shown in FIGs. 1 and 2

Example 2: Preparation of nanostructured electrical conductor as a thin film

[071] The precipitate as obtained from the Example 1 is dispersed in chloroform and then drop-cast on a cleaned and pre-patterned gold deposited glass substrate to obtain a film. The film kept is for drying for a short while. A separate KOH solution is prepared in IPA (isopropyl alcohol) as a cross-linker. The dried film is treated with this solution for cross- linking and left for drying. After that the film is then immediately washed very smoothly with methanol. The film making process is performed inside a glove box. The next round of sample is then drop-cast on the top of this film and the step of crosslinking is carried out again. This step is repeated multiple times (eg., 20 times) till the required density of the film is achieved. After the completion of filmmaking procedure the film is encapsulated by drop-casting epoxy resin and hardener mixture, in the ratio of 1 : 1 over the film. A glass sheet is subsequently placed on top. For example this has been employed to get data shown in FIG. 6 that further highlights the utility of encapsulation.

Example 3: Preparation of nanostructured electrical conductor as a thin wire

[072] In another implementation, the precipitate from Example 1 is dispersed in chloroform and then cast on a plastic ribbon (10 cm long, 3 mm wide). The film is kept for drying for a few seconds. A separate 0.01M KOH solution is prepared in IPA (isopropyl alcohol) as a cross-linker. The dried film is treated with this solution for cross-linking and left for drying. After that the film is then immediately washed with methanol. The wire making process is carried out inside a glove box. Care is also taken so as not to wash away the nanoparticles. The next round of sample is drop- cast on the top of this film and the step of crosslinking is carried out again. This procedure was repeated multiple times (usually 20) till the required density of the film was achieved. After the completion of filmmaking procedure the film was encapsulated by overlaying a 8 cm x 3 mm plastic ribbon over the original ribbon. The two ribbons are sealed at the edges using a 1 : 1 epoxy resin, hardener combination. The projecting edges of the original ribbon serve as contacts. This procedure along with its generalizations to differently sized and shaped substrates allows for the creation of stable elongated wires of low resistance nanostructured conductors.

Example 4: Preparation of nanostructured electrical conductor as a thin wire

[073] In another implementation, the elongated film from Example 3 is bundled together with a plurality of other films to produce a multi component low resistance cable.

Example 5: Preparation of an electromagnetic shield

[074] In another implementation, the precipitate from Example 1 is dispersed in chloroform and then drop-cast on a cleaned and glassy substrate. The film is kept for drying for a few seconds. A separate KOH solution is prepared in IPA (isopropyl alcohol) as a cross-linker. The dried film is treated with this solution for cross-linking and left for drying. After that the film is then immediately washed very smoothly with methanol. The film making is carried out in a glove box. Care is taken so as not to wash away the nanoparticles. The next round of sample is drop-cast on the top of this film and crosslinking step is carried out again. This procedure is repeated multiple times (usually 20) till the required density of the film is achieved. After the completion of filmmaking step, the film is encapsulated by drop-casting 1 : 1 epoxy resin and hardener mixture over the film. A glass sheet is subsequently placed on top. The resultant electromagnetic shield is used for attenuating undesirable electric and magnetic fields arising from a source. Effective attenuation is observed at a specific point of space. This process has been employed to collect data as shown in FIGs. 7, 8 and 9.

[075] The screening effects of the nanostructured electrical conductor (film) of present invention is shown in FIG.10, at optical frequencies. It shows that the nanostructured electrical conductor (film) is having a sub-100% transmission, consistent with the screening effect at optical frequencies. In this exemplary aspect, the nanostructured electrical conductor (film) is introduced between a source and detector that operate at optical frequencies

Advantages

[076] The zero or low resistance nanostructured electrical conductors (films and wires) of the present invention, minimize energy dissipation at a finite current leading to significant energy saving.

[077] The nanostructured electrical conductors are made of nanostructured composites and therefore are flexible and amenable for use in a broad variety of applications.

[078] The nanostructured electrical conductors of the present invention exhibit extremely strong diamagnetism and therefore the conductors can be far more efficient in magnetic shielding that known materials of equivalent dimensions.

[079] The nanostructured electrical conductors of the present invention can carry very large current before the onset of dissipation. The critical current in the conductors exceeds 1000-10,000 A/cm ² , which enables electrical appliances and electronic circuits to operate at large current.

[080] The implementation of an encapsulation scheme renders these nanostructured electrical conductors inert to local environmental factors. In particular, encapsulation methods enable the large scale, long term deployment of these nanostructured electrical conductors in a variety of short and long range electrical transmission and shielding applications.

[081] The nanostructured electrical conductors with such a low- resistance state find applications at an operating temperature of over 1000 K, based on the nanoparticle density.

[082] The nanostructured electrical conductors with such a low- resistance state find applications in operating magnetic field range of 14 Tesla and above.

[083] The nanostructured electrical conductors with such a low- resistance state find applications even under a very high pressure.