Nanotechnology Glossary

TryNano.org has compiled lists of many terms that apply to the field of nanotechnology.

Glossary

We acknowledge Wikipedia as a source of some of these definitions.

Adhesion: 
Property of certain dissimilar molecules that cling together due to attractive forces

Atom:
Basic unit of matter consisting of a dense, central nucleus surrounded by a cloud of negatively charged electrons.  The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons.

Atomic Force Microscope (AFM):
A very high-resolution microscope that uses a microcantilever to scan the surface of a substrate. This microscope can image and scan surface features on the order of less than a nanometer. Same as Scanning Force Microscope.

Bandgap (in solid state physics and related fields):
The energy range in a solid in which no electron states exist. For insulators and semiconductors, the band gap generally refers to the energy difference (in electron volts) between the top of the valence band and the bottom of the conduction band; it is the amount of energy required to free an outer shell electron from its orbit about the nucleus to a free state.

Biosensor:
A device that combines a biological indicator with an electrical, mechanical, or chemical sensing system.

Buckyball:
Fullerene (a family of molecules composed entirely of carbon, in the form of a hollow sphere, ellipsoid, tube, or plane) forming a spherical shape.

Bulk Properties:
Material properties that are exhibited when the material is available in large quantities, and largely affected by nanoscale interactions.

Carbon Nanotube:
A form of carbon with a nanostructure that can have a length-to-diameter ratio of up to 28,000,000:1.This ratio is significantly larger than in any other material. These cylindrical carbon molecules have novel properties that make them potentially useful in applications in nanotechnology, electronics, optics and other fields of materials science.

Catalytic Converter:  
Component on the exhaust system of an internal combustion engine used to detoxify harmful emissions before exposing to environment. This device is chemical reaction driven and catalyzed with a precious metal such as platinum.

Chemical Vapor Deposition: 
A chemical process used to produce high-purity, high-performance solid materials.  The process is often used in the semiconductor industry to produce thin films.

Chirality:
A phenomenon is said to be chiral if it is not identical to its mirror image.  Here we refer to a molecular direction property that designates a “left hand” and a “right hand” direction where the two symmetries cannot be superposed upon one another.

Ceramic:
An inorganic, non-metallic solid prepared by the action of heat and subsequent cooling.  A hard porous nonmetallic composite that can exhibit various material properties such as ferroelectricity and superconducting.

Colloid:
A chemical mixture where one substance is dispersed evenly within another. The particles of the dispersed substance are only suspended in the mixture, unlike a solution, where they are completely dissolved within.

Conductivity:
A measure of a material’s ability to conduct electric current.

Crystalline: 
A solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions.

Dendrite (crystal):
A crystal that grows in a snowflake pattern or a tree branching pattern.

Dielectric: 
An insulating material in which electrons are bound and unable to freely move within a substrate. A nonconducting substance, i.e., an insulator.

DNA:
Abbreviation of Deoxyribonucleic acid: a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses.  

DRAM: 
Dynamic Random Access Memory (DRAM), a memory that stores each bit of data in a separate capacitor within an integrated circuit. Since real capacitors leak charge, the information eventually fades unless the capacitor charge is refreshed periodically. Because of this refresh requirement, it is a dynamic memory as opposed to SRAM and other types of static memory.

Elasticity:
A material property that allows deformation under stress and reformation when stress is released.

Electron:
Subatomic particle that carries negative electric charge. The number of electrons in an atom and their energy levels determine many of the electrical properties of material. The elcetron is not known to have substructure; that is, it is not known to be made up of smaller particles.

Electron Beam Lithography:
The practice of scanning a beam of electrons in a patterned fashion across a surface covered with a film (called the resist) (“exposing” the resist) and of selectively removing either exposed or non-exposed regions of the resist (“developing”). The purpose is to create very small structures in the resist that can subsequently be transferred into another material for a number of purposes, for example for the creation of very small electronic devices.

Energy: 
A scalar physical quantity that describes the amount of work that can be performed by a force. Several different forms of energy exist, including  kinetic, potential, thermal, gravitational, sound, light, elastic, and electromagnetic energy.

Ferroelectricity:
A material property that is characterized by natural electric polarizability that can be altered by an external electric field. The term is used in analogy to ferromagnetism, in which a material exhibits a permanent magnetic moment.

Filtration: 
A mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases) by interposing a medium through which the fluid can pass, but the solids (or at least part of the solids) in the fluid are retained.

FRAM:
Ferroelectric RAM (Random Access Memory) – a memory that uses a ferroelectric layer rather than a dielectric layer to achieve non-volatility.  A non-volatile memory will retain the stored information even if it is not constantly supplied with electric power.

Fullerene: 
A family of molecules composed entirely of carbon, in the form of a hollow sphere, ellipsoid, tube, or plane. Spherical fullerenes are also called buckyballs, and cylindrical ones are called carbon nanotubes or buckytubes. Graphene is an example of a planar fullerene sheet.

Hydrophobicity/Hydrophobe:
The word hydrophobicity is obtained from combining the words for a form of water  hydro- and for fear phobos in Attic Greek).  It refers to the physical property of a molecule (known as a hydrophobe ) that is repelled from a mass of water.

Hydrophilicity/Hydrophilic:
Hydrophilicity is the tendency of a molecule to be solvated by water. Hydrophile, from the Greek (hydros) “water” and φιλια (philia) “friendship” refers to a physical property of a molecule that can bond with water.

Kinetic Energy:
The kinetic energy of an object is the extra energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its current velocity.

Liquid Crystal Display (LCD):
An electronically-modulated optical device shaped into a thin, flat panel made up of color or monochrome pixels filled with liquid crystals.  It is arrayed in front of a light source (backlight) or reflector and is often used in battery-powered electronic devices because it uses very small amounts of electric power.

LASER:
Abbreviation of “Light Amplification of Stimulated Emission Radiation”: a device that emits light (electromagnetic radiation) through a process called stimulated emission. Laser light is usually spatially coherent, which means that the light either is emitted in a narrow, low-divergence beam, or can be converted into one with the help of optical components such as lenses.

Lithography (Photolithography):
Method of fabrication of integrated circuits and microelectromechanical systems that uses alternating steps of material deposition and removal. The process selectively removes parts of a thin film or the bulk of a substrate. It uses light to transfer a geometric pattern from a photo mask to a light-sensitive chemical photo resist on the substrate. A series of chemical treatments then engrave the exposure pattern into the material underneath the photo resist.

Magnetic Memory:
Storage of information on magnetized material such as magnetic tape. Magnetic storage uses different patterns of magnetization in a magnetizable material to store data and is a form of non-volatile memory (a memory that will retain the stored information even if it is not constantly supplied with electric power.) An example of a magnetic memory is a computer hard disk drive.

Materials Science:
An interdisciplinary field involving the properties of matter and its applications to several areas of science and engineering. Materials Science investigates the relationship between the structure of materials at atomic or molecular scales and their macroscopic properties. It includes elements of applied physics and chemistry, as well as chemical, mechanical, civil and electrical engineering.

Melting Point:
The temperature point in which a material transitions from solid to liquid.

Millipede Memory (IBM):
A non-volatile memory developed by IBM that uses nanoimprints to code information and atomic force sensing to decode information. It promises a data density of more than 1 terabit per square inch (1 gigabit per square millimeter), about 4 times the density of magnetic storage available today.

Molecule:
A unit of two or more atoms held together by covalent bonds (a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms, or between atoms and other covalent bonds)

Moore’s Law: 
A long-term trend in the history of computing hardware. Since the invention of the integrated circuit in 1958, the number of transistors that can be placed inexpensively on an integrated circuit has increased exponentially, doubling approximately every two years.The trend was first observed by Intel’s co-founder Gordon E. Moore in a 1965 paper

Nanobiosensor:
A device that combines a biological indicator with an electrical, mechanical, or chemical sensing system on the nanoscale.

Nanocrystal:
A single crystalline material that has one dimension on the order of 100 nm.

Nanomaterial:
A material that exhibits distinct properties when studied on the order of less than 100 nm.

Nanometer (nm): 
 A unit of length in the metric system, equal to one billionth of a meter (i.e., 10-9 m or one millionth of a millimeter).

Nanoparticles:
Particles with size on the order of 1-100 nm.

Nanopore: 
A small pore in an electrically insulating membrane, that can be used as a single-molecule detector.

Nanoscale:
A term is used to refer to objects with dimensions on the order 1–100 nm.

Nanotechnology:
The study of materials and properties on the order of 1-100nm.

Nanowhisker:
A nanoscale structure that consists of brushes attached along a common spine.

Nanowire:
A wire of diameter on the order of a nanometer.

Non-volatile Memory: 
A memory that will retain the stored information even if it is not constantly supplied with electric power.

Nucleation:
A site in which a phase transition begins and grows outward from. Some examples of phases that may form via nucleation in liquids are gaseous bubbles, crystals, or glassy regions.

Optics:
The study of the behavior and properties of light including its interactions with matter and its detection by instruments.

Optoelectronics:
The study and application of electronic devices that source, detect and control light (including invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light). Optoelectronic devices are electrical-to-optical or optical-to-electrical transducers, or instruments that use such devices in their operation.

Optoelectronics:
The study and application of electronic devices that source, detect and control light (including invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light). Optoelectronic devices are electrical-to-optical or optical-to-electrical transducers, or instruments that use such devices in their operation.

PDMS (Polydimethylsiloxane): 
An inorganic polymer used in nanotechnology applications such as nanoimprint and soft lithography. It is the most widely used silicon-based organic polymer.

Polarization: 
A property of waves that describes the orientation of their oscillations.

Polymer: 
A large molecule (macromolecule) composed of repeating structural units typically connected by covalent chemical bonds. While polymer in popular usage suggests plastic, the term actually refers to a large class of natural and synthetic materials with a variety of properties.

Polymer Clay:
Deformable composite of polyvinyl chloride (PVC) that can be manipulated similar to a clay. This usually does not contain any actual clay.

Quantum Dot:
A semiconductor in which the electron propagation is confined in three dimensions (differing from quantum wires in which propagation is controlled in two dimensions, and quantum wells in which propagation is controlled in a single direction).

Scanning Force Microscope:
A very high-resolution microscope that uses a microcantilever to scan the surface of a substrate. This microscope can image and scan surface features on the order of less than a nanometer. Same as Atomic Force Microscope. 

Scanning Tunneling Microscope: 
A widely used instrument for viewing surfaces at the atomic level. It provides a three-dimensional profiles of viewed surfaces, which is very useful for characterizing surface roughness, observing surface defects, and determining the size and conformation of molecules and aggregates on the surface.

Semiconductor:
A material that exhibits electrical conductivity properties between those of a conductorand an insulator. [Insulators do not conduct well, while metals readily conduct.]  The conductivity of a semiconductor material can be varied under an external electrical field. Devices made from semiconductor materials are the foundation of modern electronics, including radio, computers, telephones, and many other devices. Semiconductor devices include the transistor, many kinds of diodes including the light-emitting diode, the silicon controlled rectifier, and digital and analog integrated circuits. Solar photovoltaic panels are large semiconductor devices that directly convert light energy into electrical energy.

Self Assembly: 
Processes in which a disordered system of pre-existing components forms an organized structure or pattern as a consequence of specific, local interactions among the components, without external direction.

Solar Cell
Semiconductor or organic device used to harness solar energy and convert into electrical energy.

Solution: 
A homogeneous mixture composed of two or more substances. In such a mixture, a “solute” is dissolved in another substance, known as a “solvent.”

Suspension: 
A heterogeneous fluid containing solid particles that are sufficiently large for sedimentation. An example of a suspension would be sand in water. The suspended particles are visible under a microscope and will settle over time if left undisturbed. This distinguishes a suspension from a colloid in which the suspended particles are smaller and do not settle.

Surface Area:
A measure of exposed area of na object.

Surface to Volume Ratio:
The ratio of exposed surface area to volume of the particle. In nanotechnology, very high surface to volume ratio is the enabler for many nanoscale properties.

Ultra-Violet light:
Electromagnetic radiation with a wavelength shorter than that of visible light, but longer than x-rays, in the range 10nm to 400nm, and energies from 3 eV to 124 eV. It is so named because the spectrum consists of electromagnetic waves with frequencies higher than those that humans identify as the color violet.

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