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Tweezers are small
hand tool A hand tool is any tool that is powered by hand rather than a motor. Categories of hand tools include wrenches, pliers, cutters, files, striking tools, struck or hammered tools, screwdrivers, vises, clamps, snips, hacksaws, drills, and kn ...
s used for grasping objects too small to be easily handled with the human fingers. Tweezers are thumb-driven forceps most likely derived from tongs used to grab or hold hot objects since the dawn of recorded history. In a scientific or medical context, they are normally referred to as just "forceps", a name that is used together with other grasping
surgical instrument A surgical instrument is a tool or device for performing specific actions or carrying out desired effects during a surgery or operation, such as modifying biological tissue, or to provide access for viewing it. Over time, many different kinds of ...
s that resemble
pliers Pliers are a hand tool used to hold objects firmly, possibly developed from tongs used to handle hot metal in Bronze Age Europe. They are also useful for bending and physically compressing a wide range of materials. Generally, pliers consist ...
,
pincer Pincer may refer to: * Pincers (tool) *Pincer (biology), part of an animal *Pincer ligand, a terdentate, often planar molecule that tightly binds a variety of metal ions *The Pincer move in the game of Go See also *Pincer movement The pince ...
s and
scissors Scissors are hand-operated shearing tools. A pair of scissors consists of a pair of metal blades pivoted so that the sharpened edges slide against each other when the handles (bows) opposite to the pivot are closed. Scissors are used for cutt ...
-like clamps. Tweezers make use of two third-class
lever A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or '' fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is ...
s connected at one fixed end (the
fulcrum A fulcrum is the support about which a lever pivots. Fulcrum may also refer to: Companies and organizations * Fulcrum (Anglican think tank), a Church of England think tank * Fulcrum Press, a British publisher of poetry * Fulcrum Wheels, a bicy ...
point of each lever), with the pincers at the others. When used, they are commonly held with one hand in a pen grip between the
thumb The thumb is the first digit of the hand, next to the index finger. When a person is standing in the medical anatomical position (where the palm is facing to the front), the thumb is the outermost digit. The Medical Latin English noun for thum ...
and
index finger The index finger (also referred to as forefinger, first finger, second finger, pointer finger, trigger finger, digitus secundus, digitus II, and many other terms) is the second digit of a human hand. It is located between the thumb and the mid ...
(sometimes also the middle finger), with the top end resting on the first dorsal interosseous muscle at the webspace between the thumb and index finger. Spring tension holds the grasping ends apart until finger pressure is applied. This provides an extended pinch and allows the user to easily grasp, manipulate and quickly release small or delicate objects with readily variable pressure. People commonly use tweezers for such tasks as plucking hair from the face or eyebrows, often using the term eyebrow tweezers. Other common uses for tweezers are as a tool to manipulate small objects, including for example small, particularly surface-mount, electronic parts, and small mechanical parts for
model A model is an informative representation of an object, person or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin ''modulus'', a measure. Models c ...
s and precision mechanisms. Stamp collectors use tweezers (
stamp tongs Stamp tongs are tweezers used to handle postage stamps. They are used by stamp collectors and philatelists, because they are a reliable way to hold and move stamps without damaging or getting skin oils on them. The jaws of stamp tongs are smooth ...
) to handle postage stamps which, while large enough to pick up by hand, could be damaged by handling; the jaws of stamp tongs are smooth. Another example of a specialized use is picking out the flakes of gold in gold panning. Tweezers are also used in kitchens for food presentation to remove bones from fillets of fish in a process known as pin boning, and are as tongs used to serve pieces of cake to restaurant patrons.


History

Tweezers are known to have been used in predynastic Egypt. There are drawings of Egyptian craftsmen holding hot pots over
oven upA double oven A ceramic oven An oven is a tool which is used to expose materials to a hot environment. Ovens contain a hollow chamber and provide a means of heating the chamber in a controlled way. In use since antiquity, they have been us ...
s with a double-bow shaped tool. Asiatic tweezers, consisting of two strips of metal brazed together, were commonly used in Mesopotamia and India from about 3000 BC, perhaps for purposes such as catching lice. During the
Bronze Age The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second prin ...
, tweezers were manufactured in Kerma. The word tweezer comes from etwee which describes a small case that people would use to carry small objects (such as toothpicks) with them. Etwee takes its origin from French ''étui'' "small case" from the Old French verb ''estuier'', "to hold or keep safe." Over time, the object now known as "tweezers" took on this name because the tool was commonly found in these tiny carrying cases. Eventually, the word "tweeze" was accepted as a verb in the English language. There is evidence of Roman shipbuilders pulling nails out of construction with plier-type pincers.


Types

Tweezers come in a variety of tip shapes and sizes. Blunt tip tweezers have a rounded end which can be used when a pointed object may get entangled, when manipulating
cotton swabs Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus ''Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor perc ...
, for example. Flat tip tweezers, pictured at right, have an angled tip which may be used for removing splinters. Some tweezers have a long needle-like tip which may be useful for reaching into small crevices. Triangular tip tweezers have larger, wider tips useful for gripping larger objects. Tweezers with curved tips also exist, sometimes called bent forceps. Microtweezers have an extremely small, pointed tip used for manipulating tiny electronic components and the like. There are two common forms of construction for tweezers: two fused, angled pieces of metal, or one piece of metal bent in half. The bent tweezer is cheaper to manufacture, but gives weaker grip. The fused tweezer is more expensive, but allows for a stronger grip. The width between the tips of the tweezers when no force is applied also affects how powerful the grip is. Cross-locking tweezers (aka reverse-action tweezers or self-closing tweezers) work in the opposite way to normal tweezers. Cross-locking tweezers open when squeezed and close when released, gripping the item without any exertion of the user's fingers.


Usage of traditional tweezers

Applications: *
typesetting Typesetting is the composition of text by means of arranging physical ''type'' (or ''sort'') in mechanical systems or '' glyphs'' in digital systems representing '' characters'' (letters and other symbols).Dictionary.com Unabridged. Random ...
* dealing with stamps (see Philately) * dealing with smaller coins (see Numismatics), to protect the coins these are wrapped at the tips with plastic * electronics ** soldering * cosmetics ** hair removal (eyebrow tweezers) * semiconductor technology in the form of wafer tweezers * medicine (Forceps and Tissue Forceps) * household *
jewelry making Jewellery design is the art or profession of designing and creating jewellery. This is one of civilization's earliest forms of decoration, dating back at least 7,000 years to the oldest known human societies in Indus Valley Civilization, Mesopo ...
* textile industry as iron nubs * science, laboratory *
aquascaping Aquascaping is the craft of arranging aquatic plants, as well as rocks, stones, cavework, or driftwood, in an aesthetically pleasing manner within an aquarium—in effect, gardening under water. Aquascape designs include a number of distinct styl ...
*
watchmaking A watchmaker is an artisan who makes and repairs watches. Since a majority of watches are now factory-made, most modern watchmakers only repair watches. However, originally they were master craftsmen who built watches, including all their par ...


Other kinds of tweezers

The original tweezers for mechanical gripping have given rise to a number of tools with similar action or purpose but not dependent upon mechanical pressure, including *
Optical tweezers Optical tweezers (originally called single-beam gradient force trap) are scientific instruments that use a highly focused laser beam to hold and move microscopic and sub-microscopic objects like atoms, nanoparticles and droplets, in a manner simila ...
use light to manipulate microscopic objects as small as a single atom. The momentum transfer from a focused laser beam is able to trap small particles. In the
biological science Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary ...
s, these instruments have been used to apply forces in the pico Newton range and to measure displacements in the nm range of objects ranging in size from 10 nm to over 100 mm. *
Magnetic tweezers Magnetism is the class of physical attributes that are mediated by a magnetic field, which refers to the capacity to induce attractive and repulsive phenomena in other entities. Electric currents and the magnetic moments of elementary particles ...
use magnetic forces to manipulate single molecules (such as DNA) via paramagnetic interactions. In practice it is an array of magnetic traps designed for manipulating individual biomolecules and measuring the ultra-small forces that affect their behavior. * Electric tweezers deliver an electrical signal through the tip, intended for
depilation Hair removal, also known as epilation or depilation, is the deliberate removal of body hair or head hair. Hair typically grows all over the human body and can vary in thickness and length across human populations. Hair can become more visible d ...
by damaging hair roots to prevent new hair from growing from the same root.
Electrostatic tweezers
use electrostatic voltage to induce the redistribution of charges in targeted objects, therefore generating Coulomb attraction force between tweezers and manipulated objects. Electrostatic tweezers work in a trapping mode or guiding mode. * Vacuum tweezers use differences in atmospheric pressure to grasp items from 100 micrometres in size up to parts weighing several pounds. Special vacuum tweezer tips are manufactured to handle a wide variety of items such as surface-mount electronics, optics, biological material, stamps and coins. They may be used to handle parts that are so small that conventional mechanical tweezers may cause parts to be damaged or dropped and lost. * Acoustic tweezers use sound to manipulate particles or cells in the fluid. An elegant Gor'kov potential theory is used most for small sizes compared with the incident wavelength. *
Molecular tweezers Molecular tweezers, and molecular clips, are host molecules with open cavities capable of binding guest molecules. The open cavity of the molecular tweezers may bind guests using non-covalent bonding which includes hydrogen bonding, metal coor ...
are noncyclic host molecules that have two arms capable of binding guests molecules through non-covalent bonding. * Hot, or soldering, tweezers combine the squeezing action of mechanical tweezers with heating, to grip small surface-mount electronic devices while simultaneously heating them, for
soldering Soldering (; ) is a process in which two or more items are joined by melting and putting a filler metal (solder) into the joint, the filler metal having a lower melting point than the adjoining metal. Unlike welding, soldering does not invol ...
or desoldering. * Tweezer probes are a pair of electrical
test probe A test probe is a physical device used to connect electronic test equipment to a device under test (DUT). Test probes range from very simple, robust devices to complex probes that are sophisticated, expensive, and fragile. Specific types include t ...
s fixed to a tweezer mechanism to measure voltages or other electronic circuit parameters between closely spaced pins. * Tweezers integrated with an electronic measuring device for evaluation of electrical parameters of small-size electronic components. * Carbon nano-tweezers have been fabricated by deposition of MWNT bundles on isolated electrodes deposited on tempered glass micropipettes. Those nanotube bundles can be mechanically manipulated by electricity and can be used to manipulate and transfer micro- and nano-structures. The nanotube bundles used for tweezers are about 50 nm in diameter and 2 µm in lengths. Under electric bias, two close sets of bundles are attracted and can be used as nanoscale tweezers. Other uses of the same principle are named tweezers; although such terms are not necessarily widely used their meaning is clear to people in the relevant field. E.g., Raman tweezers, which combine Raman spectroscopy with optical tweezers.


See also

*
Eyelash curler An eyelash curler is a hand-operated mechanical device for curling eyelashes for cosmetic purposes. Usually only the upper eyelashes are curled. History There were different patents of this invention between 1923 and 1940. The first known patent ...
* Instruments used in general surgery *
Optical tweezers Optical tweezers (originally called single-beam gradient force trap) are scientific instruments that use a highly focused laser beam to hold and move microscopic and sub-microscopic objects like atoms, nanoparticles and droplets, in a manner simila ...
, which use highly focused small lasers and a lens to stabilize atom or cell-sized small objects; the chief inventor won half the 2018
Nobel Prize in Physics ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...


References


External links

* * {{Hand tools Electronics work tools Hair removal Medical equipment Philatelic terminology Surgical instruments