Technology and the built world

Single-minute exchange of die

The single-minute exchange of die (SMED) is a lean manufacturing setup-reduction method developed by Shigeo Shingo at Toyota that aims to cut machine changeover times below ten minutes.

Single-molecule diode

A single-molecule diode is an electronic device in which a single molecule between two electrodes allows current in one bias direction and largely blocks it in the reverse direction.

Single-molecule electronics is a subfield of nanoelectronics in which electronic components are individual molecules wired between electrodes, studied since Aviram and Ratner proposed a molecular rectifier in 1974.

Single-molecule light-emitting diode

A single-molecule light-emitting diode (SM-LED) is a device in which a single molecule between two electrodes emits light as current passes, the molecular-scale limit of the OLED.

Single-molecule transistor

A single-molecule transistor is a three-terminal electronic device whose conducting channel is a single molecule bridging source and drain electrodes, with a gate controlling the current.

Single-page application

A single-page application (SPA) is a web application that loads a single HTML document, then updates content via JavaScript APIs such as Fetch, giving a desktop-like experience.

Single-phase electric power

Single-phase electric power, abbreviated 1φ, is alternating current distribution in which all supply voltages vary in unison, serving homes and small buildings while three-phase systems serve industrial loads.

Single-phase induction motor

A single-phase induction motor is an AC motor that runs from a single-phase supply and needs auxiliary means, such as a capacitor or shading coil, to start.

Single-photon avalanche diode

A single-photon avalanche diode (SPAD), also called a Geiger-mode avalanche photodiode, is a semiconductor photodetector that detects single photons and is used in LiDAR and PET scans.

Single-photon detector

A single-photon detector (SPD) is a device that converts individual photons into measurable electrical signals, underpinning quantum key distribution and computing, with types including SNSPDs, transition-edge sensors, and avalanche photodiodes.

Single-point urban interchange

A single-point urban interchange is a highway interchange where all freeway ramps meet the cross street at one large signalized intersection, developed in 1970 to improve traffic capacity.

Single-responsibility principle

The single-responsibility principle (SRP) is a software design principle, introduced by Robert C. Martin in the late 1990s, stating each class should have only one reason to change.

Single-screw extruder

A single-screw extruder is a continuous machine with one rotating screw inside a heated barrel that conveys, melts, and pressurizes material, most often thermoplastic polymer, through a shaping die.

Single-shield tunnel boring machine

A single-shield tunnel boring machine (single-shield TBM) is a hard-rock boring machine that thrusts against the segmental lining it erects, so boring and ring building alternate rather than overlap.

Single-shot

A single-shot firearm is a gun whose mechanism holds no more than one cartridge, requiring manual reload after each shot; it dominated firearms into the 1890s.

Single-sideband modulation

Single-sideband modulation (SSB) is an efficient form of amplitude modulation that transmits only one sideband and suppresses the carrier, halving bandwidth; it is the standard voice mode on HF radio.

Single-stage-to-orbit

A single-stage-to-orbit (SSTO) vehicle, also called one stage to orbit, reaches low Earth orbit using a single rocket stage. No Earth-launched SSTO has ever flown.

Single-walled carbon nanotube conductive additives

Single-walled carbon nanotube conductive additives are SWCNTs added in small mass fractions to lithium-ion battery electrodes, forming conductive networks at far lower loadings than carbon black.

Oct 26, 2026

SingleStore

SingleStore (formerly MemSQL, founded 2011, Y Combinator W11) is a distributed SQL HTAP database combining in-memory rowstore and on-disk columnstore; MySQL-compatible, C++, owned by Vector Capital since October 2025.

Singlet fission

Singlet fission is a photophysical process where one excited singlet molecule splits into two triplet states, potentially lifting solar cell efficiency past the Shockley–Queisser limit to about 45%.

Singlet fission sensitization of silicon solar cells

Singlet fission sensitization of silicon solar cells places an organic layer that splits one photon's energy into two excitons on silicon, potentially raising its efficiency limit from 29.4% to 34.6%.

Singlet fission solar cells

Singlet fission solar cells are photovoltaic devices that use singlet fission to convert one photon into two charge carriers, pursued mainly as an add-on to silicon cells.

Singlet-triplet qubit

The singlet-triplet qubit is a semiconductor spin qubit encoding a logical qubit in the singlet and triplet states of two electrons in a double quantum dot.

Singleton pattern

The singleton pattern is a software design pattern that restricts a class to a single instance with a global access point, a mechanism often criticized as hidden global state.

Singrauli Super Thermal Power Station

Singrauli Super Thermal Power Station is a 2,000 MW coal-fired NTPC power station at Shaktinagar in Sonebhadra district, Uttar Pradesh, whose first unit began generating in 1982.

Singtel

Singtel, or Singapore Telecommunications Limited, is a Singapore telecommunications and technology group tracing its heritage to 1879, majority-owned by Temasek, and the owner of Optus, Australia's second largest telecom provider.

Singularities of parallel manipulators

A singularity of a parallel manipulator is a configuration where a Jacobian matrix loses rank, so the mechanism gains or loses degrees of freedom and control degenerates.

Singularity avoidance

Singularity avoidance is the set of methods in robot kinematics and control that keep a manipulator away from or safely through singular poses, where required joint velocities become unbounded.

Singulation

Singulation is the process of separating a bulk stream of items into individual, spaced units moving in single file, typically for parcel scanning and sortation.