Optical Tweezers: A technique that uses LASERS to trap, image, and manipulate small objects (biomolecules, supramolecular assembles, DENDRIMERS) in three dimensional space. (From Glossary of Biotechnology and Nanobiotechnology Terms, 4th ed.)Micromanipulation: The performance of dissections, injections, surgery, etc., by the use of micromanipulators (attachments to a microscope) that manipulate tiny instruments.Optics and Photonics: A specialized field of physics and engineering involved in studying the behavior and properties of light and the technology of analyzing, generating, transmitting, and manipulating ELECTROMAGNETIC RADIATION in the visible, infrared, and ultraviolet range.Lasers: An optical source that emits photons in a coherent beam. Light Amplification by Stimulated Emission of Radiation (LASER) is brought about using devices that transform light of varying frequencies into a single intense, nearly nondivergent beam of monochromatic radiation. Lasers operate in the infrared, visible, ultraviolet, or X-ray regions of the spectrum.Elasticity: Resistance and recovery from distortion of shape.Microspheres: Small uniformly-sized spherical particles, of micrometer dimensions, frequently labeled with radioisotopes or various reagents acting as tags or markers.Biophysics: The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Neodymium: Neodymium. An element of the rare earth family of metals. It has the atomic symbol Nd, atomic number 60, and atomic weight 144.24, and is used in industrial applications.Nanotechnology: The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Molecular Motor Proteins: Proteins that are involved in or cause CELL MOVEMENT such as the rotary structures (flagellar motor) or the structures whose movement is directed along cytoskeletal filaments (MYOSIN; KINESIN; and DYNEIN motor families).Calibration: Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.Biophysical Phenomena: The physical characteristics and processes of biological systems.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Viscosity: The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Polystyrenes: Polymerized forms of styrene used as a biocompatible material, especially in dentistry. They are thermoplastic and are used as insulators, for injection molding and casting, as sheets, plates, rods, rigid forms and beads.Microfluidic Analytical Techniques: Methods utilizing the principles of MICROFLUIDICS for sample handling, reagent mixing, and separation and detection of specific components in fluids.Microscopy, Atomic Force: A type of scanning probe microscopy in which a probe systematically rides across the surface of a sample being scanned in a raster pattern. The vertical position is recorded as a spring attached to the probe rises and falls in response to peaks and valleys on the surface. These deflections produce a topographic map of the sample.Magnetics: The study of MAGNETIC PHENOMENA.Mechanotransduction, Cellular: The process by which cells convert mechanical stimuli into a chemical response. It can occur in both cells specialized for sensing mechanical cues such as MECHANORECEPTORS, and in parenchymal cells whose primary function is not mechanosensory.Microscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.