| A | B |
|---|
| shape-memory alloy SMA | A metal alloy that remembers its geometry. After it is deformed, it is heated to a specific temperature and regains its original geometry by itself |
| single-electron transistor (SET) | A transistor that switches between on and off (in computer terms, 1 and 0) by using a single electron - much smaller than a traditional transistor, which uses many electrons to switch. |
| single-walled carbon nanotube (SWNT) | A carbon nanotube with one wall. |
| soft lithography | A process that uses polymers for molding and printing micro- and nano-structures. Pioneered by George Whitesides and used for microfluidics and its descendant, nanofluidics |
| spectrometers | tools that reveal the composition of things by measuring the light absorbed or emitted by atoms or molecules. |
| spintronics | Spin-based electronics" that exploits not only an electron's charge but also its spin. |
| sputter deposition | A method of creating a thin film of metal by sputtering fine particles onto a surface. |
| stent | An expandable wire mesh used to keep a blood vessel open |
| strained silicon | New method of improving processor speed by stretching individual silicon atoms apart so electrons flow through a transistor faster with little resistance |
| substrate | The supporting surface that serves as a base. |
| scanning electron microscope (SEM) | Electron microscope that creates images of nanoscale features by bombarding the surface of a sample with a stream of electrons, scanning back and forth, and reading the reflected elec¬trons as they bounce off the surface. |
| scanning probe microscope | An instrument that studies the properties of surfaces at the atomic level by scanning an atomically sharp probe over the sample. This produces an image of the sample's topography with atomic resolution. |
| scanning tunneling microscope (STM) | The first scanning probe instrument - measures electrons tunneling between a scanning tip and a conducting surface. |
| Schottky barrier | Area of resistance to electrical conduction, occurring at the junction between the metal wires and the semiconductor in a computer processor |
| self-assembled monolayers (SAMs) | A single layer of atoms or molecules that has assembled itself under controlled conditions. This makes it possible to design surfaces at the molecular scale. |
| self-assembly | Process that creates the specific conditions under which atoms and molecules spontaneously arrange themselves into a final product. An example of self-assembly is the automatic arrangement of phospholipids into a cell wall. |
| semiconductor | Material that has more electrical conductivity than an insula¬tor (which has no conductivity) but less than a conductor; it can be made to insulate or conduct electricity in patterns, as in a computer processor. |
| superconductor | A material through which electricity flows with zero resistance |
| superlattice | A crystal formed of thin layers. A natural example is graphite |
| superposition | When an object simultaneously possesses two or more values of a specified quantity. Useful in the development of quantum computers |
| surface tension | The pull of a liquid into its most compact form to minimize the amount of energy used, keeping the surface area to a minimum |
| surfactants | "Surface-active" molecules that reduce the surface tension between two liquids. Surfactants are used in many detergents as a dispersant between oil and water. |
| tetrapods | -shaped nanocrystals that resemble children's jacks. |
| top-down fabrication | A construction process in which we first work at the large scale and then cut away until we have a smaller product. This is similar to a sculptor cutting away at a block of marble producing the final product, a statue. Compare bottom-up fabrication |
| transistor | A switch that determines whether a bit is a I or a 0. |
| uncertainty principle | In quantum mechanics, a principle made famous by Werner Heisenberg: Measuring one property in a quantum state will perturb another property. You can, for example, measure the position or momentum of an electron - but not both at once. |
| valence electrons | The electrons in the outermost shell of an atom. These electrons largely dictate the chemical reactions of the atom. |
| van der Waals | Weak electrostatic forces between atoms |
| vesicles | Micelles with two layers: a reverse micelle surrounded by a regular micelle. Resembles the walls of biological cells. |
| viscosity | The measure of resistance of a fluid - its "thickness." |
| water window | A range of frequencies in the electromagnetic spectrum that are most easily transmitted through water, making them suitable for optical imaging (800-1300nm). |
| wavelength | In physics, the distance between one wave peak and the next in a transmitted wave of radiant energy. Typically measured in nanometers. |
