Technology and the built world

Liquid hydrogen

Liquid hydrogen (LH2) is hydrogen cooled below its −252.8 °C boiling point, about 850 times denser than the gas and used as a common rocket propellant.

Liquid hydrogen tank

A liquid hydrogen tank is a double-walled, vacuum-insulated cryogenic pressure vessel storing hydrogen at about −253 °C, used for bulk storage, transport, and rocket propellant.

Liquid metal elastomer composites

Liquid metal elastomer composites, also called liquid metal embedded elastomers (LMEEs), are soft materials that disperse droplets of liquid gallium alloys in rubber, conducting electricity while stretching.

Liquid metal electronics

Liquid metal electronics are electronic circuits, sensors, and thermal interfaces built from gallium alloys liquid at room temperature, such as EGaIn and Galinstan, enabling stretchable, self-healing wearable and soft-robotic devices.

Liquid metal reconfigurable electronics

Liquid metal reconfigurable electronics are circuits, antennas, and sensors built from liquid gallium alloys like EGaIn and Galinstan, whose shape and electrical function change mechanically, electrically, or thermally.

Liquid metal thermal energy storage

Liquid metal thermal energy storage is a high-temperature storage method in which molten metals such as sodium, lead, or tin move heat into and out of a solid storage medium.

Liquid neural network

A liquid neural network is a recurrent neural network whose hidden units follow differential equations with input-dependent time constants, letting the network adapt continuously to new data.

Liquid organic hydrogen carriers

Liquid organic hydrogen carriers (LOHCs) are organic liquids that store hydrogen by reversible catalytic bonding, allowing transport at ambient temperature and pressure using existing fuel infrastructure.

Liquid oxygen

Liquid oxygen (LOX) is a cryogenic fluid used medically, industrially, and as a rocket oxidizer. It is produced by cooling and separating oxygen from nitrogen in air.

Liquid packaging board

Liquid packaging board (LPB) is a food-grade paperboard made from virgin wood fiber and laminated with polyethylene, sometimes with aluminum foil, to hold milk, juice, and other liquid foods in cartons.

Liquid phase sintering

Liquid phase sintering is a powder-metallurgy process in which a liquid phase densifies powder particles into a solid component, faster and at lower temperatures than solid-state sintering.

Liquid Piston Compression

Liquid piston compression is a method of compressing gas in which a pumped liquid column, usually water, displaces the gas, removing heat efficiently for near-isothermal compressed air energy storage.

Liquid piston compressor

A liquid piston compressor is a positive-displacement gas compressor in which a rising liquid column displaces and compresses the gas, replacing the solid piston and crankshaft.

Liquid silicon infiltration

Liquid silicon infiltration (LSI) is a fabrication process in which capillary forces draw molten silicon into porous carbon preforms, forming dense silicon carbide and ceramic composites.

Liquid sunlight

Liquid sunlight (液态阳光), or liquid solar fuel, is a technology named in 2018 that stores renewable electricity as liquid methanol from green hydrogen and captured CO2.

Liquid types

Liquid types are refinement types, data types augmented with logical predicates verifying program invariants, introduced by Rondon, Kawaguchi, and Jhala at UC San Diego at PLDI 2008.

Liquid-crystal display

A liquid-crystal display (LCD), or LC display, is a flat-panel display using liquid crystals to control light per pixel, invented at RCA in New Jersey from 1963 to 1968.

Liquid-metal thermal switches

A liquid-metal thermal switch is a device whose thermal conductance is reversibly switched by moving room-temperature liquid metal such as Galinstan between a heat source and sink.

Liquid-phase epitaxy

Liquid-phase epitaxy (LPE) is a crystal growth method that deposits a thin single-crystalline layer from a solution onto a substrate, used for LEDs and compound semiconductors.

Liquid-propellant rocket

A liquid-propellant rocket, also called a liquid-fueled rocket, carries its fuel and oxidizer as liquids in separate tanks and burns them for thrust; Robert Goddard first flew one in 1926.

Liquipedia

Liquipedia, also known as Liquipedia.net, is a volunteer-run wiki network covering esports, launched by Team Liquid in 2009 and covering more than 17 games, including Counter-Strike and Dota 2.

LIRMM

LIRMM, the Laboratoire d'Informatique, de Robotique et de Microélectronique de Montpellier, is a French joint research unit of the University of Montpellier and CNRS, founded in 1992 and based in Montpellier.

Lisa Brannon-Peppas

Lisa Brannon-Peppas is an American biomedical engineer elected to the National Academy of Engineering in 2025, known for biomaterials swelling theory and targeted nanoparticle cancer drug delivery.

Lisa Kelly (trucker)

Lisa Kelly, born 1980, is an American trucker from Alaska who became the first woman on Ice Road Truckers in 2009 and starred in IRT: Deadliest Roads.

Lisa Nowak

Lisa Nowak, née Caputo, is an American former naval flight officer and NASA astronaut who flew STS-121 in 2006 and was the first astronaut dismissed by NASA, in 2007.

LISA Pathfinder

LISA Pathfinder was a European Space Agency technology-demonstration spacecraft that flew from December 2015 to June 2017, proving drag-free flight and picometre laser metrology for the LISA gravitational-wave observatory.

Lisbon Airport

Lisbon Airport, also known as Humberto Delgado Airport or Portela airport, is Portugal's main international airport, opened in 1942 and hub of TAP Air Portugal.

Lisi (company)

LISI, short for Link Solutions for Industry, is a French family-owned group making fasteners and assembly components, with 38 production sites and more than 9,600 employees.

Liskov substitution principle

The Liskov substitution principle (LSP) is an object-oriented design rule, introduced by Barbara Liskov in 1987, stating that subtypes must be usable wherever supertypes are expected.