Tweezers
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Tweezers are small
.Tweezers make use of two third-class levers connected at one fixed end (the fulcrum 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 and index finger (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
History
Tweezers are known to have been used in predynastic Egypt. There are drawings of Egyptian craftsmen holding hot pots over ovens 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.[2] During the Bronze Age, tweezers were manufactured in Kerma.[3]
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.
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
- 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)
- nail art (application of gems, stickers etc to fingernails or toenails as part of a manicure)
- semiconductor technology in the form of wafer tweezers
- medicine (Forceps and Tissue Forceps)
- household
- jewelry making
- textile industry as iron nubs[clarification needed]
- science, laboratory
- aquascaping
- watchmaking
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
- biological sciences, 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.[citation needed]
- Magnetic tweezers 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.
- depilationby 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.[6]
- 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.
- non-covalentbonding.
- 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 solderingor desoldering.
- Tweezer probes are a pair of electrical test probes 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.[7]
- 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.[8]
See also
- Eyelash curler
- Instruments used in general surgery
- Optical tweezers, 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
References
- ^ Tocantweezer (December 2015). "Christmas Bakery – Santa Claus Cake Made With Gerald Tweezers". Tocan-Tweezer.org. Archived from the original on 2015-12-22. Sourceforge project. (CC-BY-SA)
- ISBN 978-0-8196-0123-0.
- ISBN 978-0-313-32501-4.
- ^ "Eyelash made in different sizes and shapes". qualitybeautystore.com. 2 July 2019.
- PMID 19730608.
- PMID 34992136.
- ^ "Multimeter/LCR Meter tweezers". advancedevices.com. Archived from the original on July 19, 2013. Retrieved January 17, 2020.
- ^ Hewett J (27 February 2002). "Raman tweezers probe living cells". optics.org. Archived from the original on March 3, 2008. Retrieved 2020-01-17.