 | This article has multiple issues. Please help improve it or discuss these issues on the talk page . (Learn how and when to remove these messages)
|
The Slide (stylized SLIDE) is a magnetically levitating hoverboard demonstration developed by Lexus, [1] who built a skate park in Barcelona, Spain specifically for the project. The system was built as a promotional demonstration and was not on sale to the public. [1] [2]
The overall project took about 57 weeks to complete. [3] [4] The SLIDE was teased in June 2015 and was officially revealed 5 August of the same year. [5] [6] Dietmar Berger, a magnetic levitation engineer, and Ludwig Schultz, an engineer of superconducting levitation, were mostly responsible for the design of the system. [7] [8] Professional skateboarder Ross McGouran was the main rider for both prototype testing and promotional demonstration. [3]
The main focus of the demonstration is the levitation of the hoverboard, which was achieved through the use of superconductors inside the board and a magnetic track. The board itself was made of bamboo and carbon fibre support structures. [9] The board had 32 yttrium barium copper oxide superconductors cooled by liquid nitrogen. [10]
Superconductors are conductors that have no internal resistance as long as they are kept below a certain temperature based on the particular material. [11] When a metal has no internal resistance, a current running through the metal will run forever without a power source. When a superconductor is subjected to a magnetic field, the superconductor aligns itself with the magnetic field and can remain in a fixed position above it. [12] In order to maintain the required temperature, this system uses liquid nitrogen to cool it down to −197 °C (76.1 K; −322.6 °F). [8] [13] [14] Because of the transfer of heat energy from the magnets to the liquid nitrogen, the nitrogen boils and eventually evaporates away. [13] This makes it difficult to have a constant supply of liquid nitrogen to continually cool down the superconductors, and the system can only operate for an average time of about 20 minutes on maximum liquid nitrogen onboard capacity. [15]
The track built by Lexus for the SLIDE project is in Cubelles, Barcelona, Spain. [16] The entire skate park has magnetic tracks concealed beneath a thin layer of wood. The magnetic track pulls the board along the path. [3] All the uphill and downhill slopes of the track were specifically designed to ensure the magnetic field has enough momentum to maintain the board's movement. [3]
In physics, cryogenics is the production and behaviour of materials at very low temperatures.
Superconductivity is a set of physical properties observed in superconductors: materials where electrical resistance vanishes and magnetic fields are expelled from the material. Unlike an ordinary metallic conductor, whose resistance decreases gradually as its temperature is lowered, even down to near absolute zero, a superconductor has a characteristic critical temperature below which the resistance drops abruptly to zero. An electric current through a loop of superconducting wire can persist indefinitely with no power source.
Skateboarding is an action sport that involves riding and performing tricks using a skateboard, as well as a recreational activity, an art form, an entertainment industry job, and a method of transportation. Originating in the United States, skateboarding has been shaped and influenced by many skateboarders throughout the years. A 2009 report found that the skateboarding market is worth an estimated $4.8 billion in annual revenue, with 11.08 million active skateboarders in the world. In 2016, it was announced that skateboarding would be represented at the 2020 Summer Olympics in Tokyo, for both male and female teams. Skateboarding made its Olympic debut in 2020 and was included in the 2024 games.
Technological applications of superconductivity include:
A skatepark, or skate park, is a purpose-built recreational environment made for skateboarding, BMX, scootering, and aggressive inline skating. A skatepark may contain half-pipes, handrails, funboxes, vert ramps, stairsets, quarter pipes, ledges, spine transfers, pyramids, banked ramps, full pipes, pools, bowls, snake runs, and any number of other objects.
Liquid nitrogen (LN2) is nitrogen in a liquid state at low temperature. Liquid nitrogen has a boiling point of about −196 °C (−321 °F; 77 K). It is produced industrially by fractional distillation of liquid air. It is a colorless, mobile liquid whose viscosity is about one-tenth that of acetone (i.e. roughly one-thirtieth that of water at room temperature). Liquid nitrogen is widely used as a coolant.
A superconducting magnet is an electromagnet made from coils of superconducting wire. They must be cooled to cryogenic temperatures during operation. In its superconducting state the wire has no electrical resistance and therefore can conduct much larger electric currents than ordinary wire, creating intense magnetic fields. Superconducting magnets can produce stronger magnetic fields than all but the strongest non-superconducting electromagnets, and large superconducting magnets can be cheaper to operate because no energy is dissipated as heat in the windings. They are used in MRI instruments in hospitals, and in scientific equipment such as NMR spectrometers, mass spectrometers, fusion reactors and particle accelerators. They are also used for levitation, guidance and propulsion in a magnetic levitation (maglev) railway system being constructed in Japan.
Flux pinning is a phenomenon that occurs when flux vortices in a type-II superconductor are prevented from moving within the bulk of the superconductor, so that the magnetic field lines are "pinned" to those locations. The superconductor must be a type-II superconductor because type-I superconductors cannot be penetrated by magnetic fields. Some type-I superconductors can experience the effects of flux pinning if they are thin enough. If the material's thickness is comparable to the London penetration depth, the magnetic field can pass through the material. The act of magnetic penetration is what makes flux pinning possible. At higher magnetic fields the superconductor allows magnetic flux to enter in quantized packets surrounded by a superconducting current vortex. These sites of penetration are known as flux tubes. The number of flux tubes per unit area is proportional to the magnetic field with a constant of proportionality equal to the magnetic flux quantum. On a simple 76 millimeter diameter, 1-micrometer thick disk, next to a magnetic field of 28 kA/m, there are approximately 100 billion flux tubes that hold 70,000 times the superconductor's weight. At lower temperatures the flux tubes are pinned in place and cannot move. This pinning is what holds the superconductor in place thereby allowing it to levitate. This phenomenon is closely related to the Meissner effect, though with one crucial difference — the Meissner effect shields the superconductor from all magnetic fields causing repulsion, unlike the pinned state of the superconductor disk which pins flux, and the superconductor in place.
Levitation is the process by which an object is held aloft in a stable position, without mechanical support via any physical contact.
A hoverboard is a fictional levitating board used for personal transportation, first described in science-fiction, and made famous by the appearance of a skateboard-like hoverboard in the film Back to the Future Part II. Many attempts have been made to invent a functioning hoverboard.
Maglev is a system of rail transport whose rolling stock is levitated by electromagnets rather than rolled on wheels, eliminating rolling resistance.
The Mendocino motor is a solar-powered magnetically levitated electric motor. With a very low power output, they are generally used as technical demonstrations only, but are a popular construction project with electronic enthusiasts.
Superconducting electric machines are electromechanical systems that rely on the use of one or more superconducting elements. Since superconductors have no DC resistance, they typically have greater efficiency. The most important parameter that is of utmost interest in superconducting machine is the generation of a very high magnetic field that is not possible in a conventional machine. This leads to a substantial decrease in the motor volume; which means a great increase in the power density. However, since superconductors only have zero resistance under a certain superconducting transition temperature, Tc that is hundreds of degrees lower than room temperature, cryogenics are required.
Street skateboarding is a skateboarding discipline which focuses on flat-ground tricks, grinds, slides and aerials within urban environments, and public spaces. Street skateboarders meet, skate, and hang out in and around urban areas referred to as "spots," which are commonly streets, plazas or industrial areas. To add variety and complexity to street skateboarding, obstacles such as handrails, stairs, walls, flower beds, bins, park benches, picnic tables, and other street furniture may be traversed as single tricks or as part of a series of consecutive tricks called a "line."
Magnetic levitation (maglev) or magnetic suspension is a method by which an object is suspended with no support other than magnetic fields. Magnetic force is used to counteract the effects of the gravitational force and any other forces.
A self-balancing scooter is a self-balancing personal transporter consisting of two motorized wheels connected to a pair of articulated pads on which the rider places their feet. The rider controls the speed by leaning forward or backward, and direction of travel by twisting the pads.
A skate spot is a location used for skateboarding.
Hydrogen cryomagnetics is a term used to denote the use of cryogenic liquid hydrogen to cool the windings of an electromagnet. A key benefit of hydrogen cryomagnetics is that low temperature liquid hydrogen can be deployed simultaneously both as a cryogen to cool electromagnet windings and as an energy carrier. That is, powerful synergistic benefits are likely to arise when hydrogen is used as a fuel and as a coolant. Even without the fuel/coolant synergies, hydrogen cryomagnetics is an attractive option for the cooling of superconducting electromagnets as it eliminates dependence upon increasingly scarce and expensive liquid helium. For hydrogen cryomagnetic applications specialist hydrogen-cooled electromagnets are wound using either copper or superconductors. Liquid-hydrogen-cooled copper-wound magnets work well as pulsed field magnets. Superconductors have the property that they can operate continuously and very efficiently as electrical resistive losses are almost entirely avoided. Most commonly the term "hydrogen cryomagnetics" is used to denote the use of cryogenic liquid hydrogen directly, or indirectly, to enable high temperature superconductivity in electromagnet windings.
Alec Beck is an American professional skateboarder, public space advocate, skatepark designer, and Olympic coach.