Abstract: The successful fabrication of alloy foam (or porous alloy) is very rare, despite their potentially better properties and wider applicability than pure metallic foams. The processing of three-dimensional copper-nickel alloy foams is achieved through a strategic solid-solution alloying method based on oxide powder reduction or sintering processes, or both. Solid-solution alloy foams with five different compositions are successfully created, resulting in open-pore structures with varied porosity. The corrosion resistance of the synthesized copper-nickel alloy foams is superior to those of the pure copper and nickel foams.

Abstract: Morphology, microstructure, compressive behavior, and biocorrosive properties of magnesium or magnesium alloy foams allow for their use in biodegradable biomedical, metal-air battery electrode, hydrogen storage, and lightweight transportation applications. Magnesium or Mg alloy foams are usually very difficult to manufacture due to the strong oxidation layer around the metallic particles; however, in this invention, they can be synthesized via a camphene-based freeze-casting process with the addition of graphite powder using precisely controlled heat-treatment parameters. The average porosity ranges from 45 to 85 percent and the median pore diameter is about a few tens to hundreds of microns, which are suitable for bio and energy applications utilizing their enhanced surface area.

Abstract: An innovative fuel cell system with membrane electrode assemblies (MEAs) includes a polymer electrolyte membrane, a gas diffusion layer (GDL) made of porous metal foam, and a catalyst layer. A fuel cell has a metal foam layer that improves efficiency and lifetime of the conventional gas diffusion layer, which consists of both gas diffusion barrier (GDB) and microporous layer (MPL). This metal foam GDL enables consistent maintenance of the suitable structure and even distribution of pores during the operation. Due to the combination of mechanical and physical properties of metallic foam, the fuel cell is not deformed by external physical strain. Among many other processing methods of open-cell metal foams, ice-templating provides a cheap, easy processing route suitable for mass production. Furthermore, it provides well-aligned and long channel pores, which improve gas and water flow during the operation of the fuel cell.

Abstract: A three-dimensional metallic foam is fabricated with an active oxide material for use as an anode for lithium batteries. The porous metal foam, which can be fabricated by a freeze-casting process, is used as the anode current collector of the lithium battery. The porous metal foam can be heat-treated to form an active oxide material to form on the surface of the metal foam. The oxide material acts as the three-dimensional active material that reacts with lithium ions during charging and discharging.

Abstract: A sodium-chloride-space-holder process with two-step heat treatment is used to create an open-porous metal foam (e.g., titanium foam) with a high porosity of about 70 to 90 percent for use in load-bearing applications. A mechanically reliable titanium foam is manufactured using a space-holder method containing two-step heat treatment where a sodium chloride powder is first sieved for desired pore size range, mixed with titanium powder, and compacted under pressure at high temperature. An additional heat treatment is applied to further strengthen the chemical bonding between the titanium particles after the removal of sodium chloride in water to create pores. This process uses a pneumatic pressing machine in combination with a furnace under an argon gas to simultaneously apply both the pressure and temperature. The resulting titanium foam is chemically well bonded and has enhanced durability for proper used in structural applications.

Abstract: An innovative fuel cell system with membrane electrode assemblies (MEAs) includes a polymer electrolyte membrane, a gas diffusion layer (GDL) made of porous metal foam, and a catalyst layer. A fuel cell has a metal foam layer that improves efficiency and lifetime of the conventional gas diffusion layer, which consists of both gas diffusion barrier (GDB) and microporous layer (MPL). This metal foam GDL enables consistent maintenance of the suitable structure and even distribution of pores during the operation. Due to the combination of mechanical and physical properties of metallic foam, the fuel cell is not deformed by external physical strain. Among many other processing methods of open-cell metal foams, ice-templating provides a cheap, easy processing route suitable for mass production. Furthermore, it provides well-aligned and long channel pores, which improve gas and water flow during the operation of the fuel cell.

Abstract: A metal-foam structure is used to shield or reduce harmful electromagnetic waves that are generated by electronic devices. A metal-foam material has regulated pores and is incorporated in an electronic device. The metal foam structure shields, prevents, or reduces harmful electromagnetic waves generated by the electronic device from reaching the human body or interfering with a sensitive electronic component. This metal foam is a relatively lightweight material having regulated microscale pore structure. The pores in the metal foam can also form directionality relative to the direction of incoming electromagnetic waves for more effective reflection or absorption of electromagnetic waves. The metal foam can also be used as both an electromagnetic-shielding and a heat-dissipating component for electronics including popular consumer electronics such as mobile phones, notebooks, and high-power desktop computers.

Abstract: A three-dimensional metallic foam is fabricated with an active oxide material for use as an anode for lithium batteries. The porous metal foam, which can be fabricated by a freeze-casting process, is used as the anode current collector of the lithium battery. The porous metal foam can be heat-treated to form an active oxide material to form on the surface of the metal foam. The oxide material acts as the three-dimensional active material that reacts with lithium ions during charging and discharging.

Abstract: A metal foam ball, several millimeters in diameter, is manufactured to have an open-pore structure to absorb fluid (e.g., gas and liquid) such as water or lubricant. As an example, a copper foam ball is manufactured via a freeze casting method using prepared oxide powder slurry where a spherical silica gel mold is used to freeze the slurry, which is subsequently dried at low temperature in vacuum and then sintered at high temperature. For improved oxidation, copper alloy foam ball or copper foam ball coated with tin can also be manufactured through the same method. For improved strength, steel, copper-nickel alloy, or titanium foam ball can also be manufactured through the same method.

Abstract: A three-dimensional (3D) printing device presented in this invention has a novel printing head design that can be used with a cost-effective 3D printing ink based on cost-competitive camphene solvent utilizing its burning-free, room-temperature solidifying and sublimating properties for 3D printing purposes. The unique combination of the new printing head with pressured air control and the invented ink allows for a mass-production of complex metallic components and parts with a variety of compositions for use in advanced manufacturing in a highly cost-effective way.

Abstract: A capacitor and supercapacitor design are based on metal-foam electrodes. An electrolytic capacitor has a metal foam dielectric (e.g., aluminum oxide, titanium oxide, iron oxide, or others). An electric double-layer supercapacitor has an electrode with metal foam (e.g., copper, nickel, titanium, iron, steel alloy, or aluminum) filled with activated carbon, or graphene, or metal foam with activated carbon foam, or any combination of these to enhance the electrical conductivity and thus the power and capacity of the cell. A pseudocapacitor device has an electrode with metal foam (e.g., iron, cobalt, nickel, copper, titanium, aluminum, magnesium, tin, manganese, and stainless steel, and their alloy foams) coated with an oxide- or hydroxide-based material containing highly active zones. The pseudocapacitor metal-foam electrode can also be filled with activated carbon in the form of a slurry to further enhance its capacity.

Abstract: A gas sensing device is manufactured with three dimensionally connected metal oxide foam structure of large surface area and elongated channel pores within the three-dimensional porous structure for gas sensing applications, thereby increasing the surface area of the sensing layer and expediting sensitivity and sensor response. A gas sensor device includes the fabricated metal-oxide-foam sensing material attached via silver paste to platinum electrodes and ruthenium heater that are printed on low temperature co-fired ceramic substrate. This device will provide improved gas sensing performance with improved sensitivity and response time. Gas sensors including the metal oxide foam sensing material exhibit higher sensitivity to toxic gases such as ethanol and carbon monoxide due to the large surface area achieved from the porous three-dimensional structure providing increased chemical reaction sites and the larger porous channels allowing gases to easily pass, shortening the gas diffusion reaction path.

Abstract: A facile method is based on a pack-cementation process using large-area copper foil instead of copper powder. By controlling a pack-cementation time and an amount of alloying element (e.g., aluminum), a hierarchical microporous or nanoporous copper can be created. When coated with tin active material, the hierarchical microporous or nanoporous copper can be used as an advanced lithium-ion battery anode. A coin-cell test exhibited a four-fold higher areal capacity (e.g., 7.4 milliamp-hours per square centimeter without any performance degradation up to 20 cycles) as compared to a traditional graphite anode.

Abstract: The successful fabrication of alloy foam (or porous alloy) is very rare, despite their potentially better properties and wider applicability than pure metallic foams. The processing of three-dimensional copper-nickel alloy foams is achieved through a strategic solid-solution alloying method based on oxide powder reduction or sintering processes, or both. Solid-solution alloy foams with five different compositions are successfully created, resulting in open-pore structures with varied porosity. The corrosion resistance of the synthesized copper-nickel alloy foams is superior to those of the pure copper and nickel foams.

Abstract: An innovative fuel cell system with membrane electrode assemblies (MEAs) includes a polymer electrolyte membrane, a gas diffusion layer (GDL) made of porous metal foam, and a catalyst layer. A fuel cell has a metal foam layer that improves efficiency and lifetime of the conventional gas diffusion layer, which consists of both gas diffusion barrier (GDB) and microporous layer (MPL). This metal foam GDL enables consistent maintenance of the suitable structure and even distribution of pores during the operation. Due to the combination of mechanical and physical properties of metallic foam, the fuel cell is not deformed by external physical strain. Among many other processing methods of open-cell metal foams, ice-templating provides a cheap, easy processing route suitable for mass production. Furthermore, it provides well-aligned and long channel pores, which improve gas and water flow during the operation of the fuel cell.

Abstract: Anode and cathode electrodes of a rechargeable lithium-ion battery are manufactured using metal foam. This lithium-ion battery with the metal-foam electrodes can have pores coated or filled, or both, with high-capacity active materials for greater energy density, better safety, improved power, and longer cycle life. Aluminum (or nickel) and copper metal-foam electrodes are manufactured using space-holder and freeze-casting methods. An anode can be filled with a graphite or silicon slurry, or a combination. A cathode can be filled with a lithium cobalt oxide (or other higher-capacity active materials) slurry. The relatively thick metal-foam electrodes are attached to the cell, separated by a separator, and wetted by an electrolyte, forming a high-capacity secondary battery. The battery will have higher density, improved power, and good cycle life.

Abstract: Morphology, microstructure, compressive behavior, and biocorrosive properties of magnesium or magnesium alloy foams allow for their use in biodegradable biomedical, metal-air battery electrode, hydrogen storage, and lightweight transportation applications. Magnesium or Mg alloy foams are usually very difficult to manufacture due to the strong oxidation layer around the metallic particles; however, in this invention, they can be synthesized via a camphene-based freeze-casting process with the addition of graphite powder using precisely controlled heat-treatment parameters. The average porosity ranges from 45 to 85 percent and the median pore diameter is about a few tens to hundreds of microns, which are suitable for bio and energy applications utilizing their enhanced surface area.

Abstract: An electrode for the use of an advanced lithium battery is fabricated using three-dimensionally structured metal foam coated with an active material. The metal foam is porous metal foam that can be used as an anode current collector of a lithium-ion battery and is coated with an anode active material, such as tin, through a sonication-assisted electroless plating method. Additionally, the coated metal foam is heat-treated at an appropriate temperature in order to improve the integrity of the coating layer and hence, the cyclic performance of the lithium-ion battery.

Abstract: An innovative fuel cell system with MEAs includes a polymer electrolyte membrane, a gas diffusion layer (GDL) made of porous metal foam, and a catalyst layer. A fuel cell has a metal foam layer that improves efficiency and lifetime of the conventional gas diffusion layer, which consists of both gas diffusion barrier (GDB) and microporous layer (MPL). This metal foam GDL enables consistent maintenance of the suitable structure and even distribution of pores during the operation. Due to the combination of mechanical and physical properties of metallic foam, the fuel cell is not deformed by external physical strain. Among many other processing methods of open-cell metal foams, ice-templating provides a cheap, easy processing route suitable for mass production. Furthermore, it provides well-aligned and long channel pores, which improve gas and water flow during the operation of the fuel cell.

Abstract: An electrode for the use of an advanced lithium battery is fabricated using three-dimensionally structured metal foam coated with an active material. The metal foam is porous metal foam that can be used as an anode current collector of a lithium-ion battery and is coated with an anode active material, such as tin, through a sonication-assisted electroless plating method. Additionally, the coated metal foam is heat-treated at an appropriate temperature in order to improve the integrity of the coating layer and hence, the cyclic performance of the lithium-ion battery.