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Sharpened to a Single Atom

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"The edges of the Shikra blade have been honed to the thickness of a single atom. I must keep my hand very still, for fear that one slip will cut you... in half."
Qetesh, Stargate: Continuum

Weapons that have been sharpened to a single atom are a particular type of Absurdly Sharp Blade that are so sharp, their cutting edge can be measured in terms of atoms or molecules, often being just a single molecule wide. This usually gives the weapons Absurd Cutting Power, but generally requires the blade to be made out of some sort of Unobtanium to maintain that sharpness without dulling instantly (or just shattering into a million pieces) the first time it's used. For these reasons, the trope is most frequently encountered in Science Fiction settings.

A common term used for this is "monomolecular". Most often seen with knives or swords, but occurs from time to time with Razor Floss, too. This can be particularly troublesome, as monomolecular wire is usually functionally invisible, and walking into one can slice through vital bits without being immediately noticed.

A weapon is only an example of this trope when a specific (very small) width is given for the blade's edge; if no specific measurement is given, then it's just an Absurdly Sharp Blade.


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    Anime & Manga 
  • Eve from Black Cat managed to manipulate her Prehensile Hair to do this later in the manga.
  • In Kiddy Grade, Sinistra and Dextera's ship can split into two, creating a 'monodimensional' blade between the halves.
  • In Hellsing Ultimate, Walter C. Dornez, the Hellsing family's personal butler, uses a set of monomolecular razor wires to devestating effect in combat, where they are shown capable of effortlessly dismembering and slicing apart armies of humans and ghouls alike. It can cut through steel and concrete, and at one point they are even used to bring down several Black Hawk helicopters. Walter controls them as extensions of his own body, and they seem to be of infinite length and durability, as they never break in the series.
  • Quinn Garland of Magical Record Lyrical Nanoha Force slashes at Tohma, Erio, and Caro with an unknown attack from her sword at long-range that isn't magic or some sort of Divider or Virus based power that could slice through things that normal swords can't slice. It's eventually revealed to be her extending her sword by projecting a particle-like blade from its tip.
  • A non Sci-Fi example shows up in Saint Seiya Omega. Hyperion's sword, the Cataclysm Slash, can cut a proton in two. In this case, the sword was forged and given to him by a god.
  • Mamoru's katana from Until Death Do Us Part is a high tech monomolecular blade, able to break the bonds between molecules and cut anything (if the katana's angled properly). At one point he cuts a gun in half; when the pieces are pushed back together, it appears as if the gun was undamaged, because the cut is that sharp.

    Comic Books 
  • Nemesis, a member (and former enemy) of Alpha Flight, uses a saber whose blade is only a single molecule wide.
  • In Marvel's Infinity, Corvus Glaive wields a glaive so sharp that it is capable of splitting atoms, cutting through virtually anything.
    • It's presumably the same reason why he can cut through Vision's vibranium body in the film inspired by that comics, Avengers: Infinity War, although it's never stated onscreen.
  • In Kingdom Come Wonder Woman has a magic sword that is sharp enough to "carve the electrons off an atom". Leaving aside the ways that doesn't actually make sense, it suggests a blade with an edge thinner than an atom. Superman accidentally cuts himself on the blade (since it's Wonder Woman, it's likely the sharpness is due to magic, which Superman has always been vulnerable to).
  • Legion of Super-Heroes: The Persuader, a member of the Fatal Five, has an axe that he claims is so sharp it can shatter electrons. In some stories, it is sharp enough to cut through the force of gravity (Try not to think about that too hard).

    Fan Works 
  • In Harry Potter and the Methods of Rationality, Harry's early experimentation with transfiguration includes the creation of monomolecular wire, made up of braided carbon nanotubes. He uses it in the climactic confrontation to remove the Death Eaters' heads and Lord Voldemort's hands (which are holding his wand and a gun), as actually killing Voldemort is contraindicated by his large number of inaccessible horcruxes.
  • In The Last Son, Superman finds a sword that belonged to one of his ancestors named Von-El. This sword is not only sharp enough to wound Kryptonians powered by a yellow sun, but also has a monomolecular lash concealed in the hilt, which can be used as a long-ranged weapon (he needs a special gauntled to grab it without cutting himself).
  • In The (Questionable) Burdens of Leadership of a Troll Emperor, one of the booby traps Reiko sets on the Wraith hive ship is a length of monomolecular wire at waist height. According to her, the slain patrol probably didn't even feel it until their torsos hit the ground.

    Film — Live Action 
  • Alita: Battle Angel: Zapan carries the Damascus blade, an ancient weapon that is honed to a mono-molecular edge. Zapan experiences it first-hand when Alita takes it from him and slices his face off. It continues to hold up to the hype throughout the movie when she just cuts through everything and everyone. She can make it even sharper by infusing it with plasma from her cyborg body.
  • The assassin in Johnny Mnemonic has a monomolecular wire concealed in a prosthetic thumb tip. The movie makes it glow because an invisible wire whip wouldn't be interesting to look at.
  • The Man in the White Suit is a film about the invention of a completely dirt-proof fabric. It's not emphasised, but it's mentioned in passing in the dialogue about the development of the new material that the threads are, in effect, molecular monofilaments — causing problems in handling and cutting them. It evidently doesn't occur to any of the characters that this could have other applications. This may be one of the earliest occurrences of the concept in fiction.
  • In Stargate: Continuum, the blade held by Ba'al (later stolen by Qetesh) has an edge "only one atom thick", making it thin enough to cut Lord Ba'al clean in half.



  • Larry Niven:
    • The variable sword used in the Known Space stories is a length of monomolecular wire held straight by a projected stasis field. There's a little red ball at the end of the wire so the wielder can tell where the otherwise invisible "blade" ends. There's also Sinclair molecule chain, used as ramship tow cable, that's essentially the same thing with no stasis field.
    • The Descent of Anansi features another monofilament cable where, in effect, a space shuttle is lowered to Earth on a cable. At one point one of the baddies drifts into the cable and realises that it is already inside the faceplate of his spacesuit by the time he notices anything.
    • In a couple of the Ringworld novels, one of the 'strings' that held the shadow squares that provided a day/night cycle to the Ringworld had been broken and eventually fell to the surface, where it was described as a foggy cloud that minced anything that touched it. One of the main characters is semi-decapitated (lost one of his two heads, but he had spares in storage) when the natives found the end spool and strung some of the wire up as a trap.
  • Terry Pratchett:
    • The Dark Side of the Sun features a monomolecular blade (which shatters when swung against a villain gifted with luck manipulation).
    • In the Discworld series, both Death's scythe and sword have edges one molecule thick. Thinner, in fact — they glow blue because of the energy released when they cut the air apart (Genius Bonus: atoms do in fact glow blue when sliced apart. It's called Cherenkov radiation). At one point, he sharpened it so finely that it was able to cut several inches ahead of its physical edge, and could cut a person's sentence in half by swinging it.

Individual works

  • Brasyl, by Ian McDonald, one-ups monomolecular-edged knives with the Q-blades: they have an edge that can cut quantum strings. Y'know, the stuff that decides matter is matter; essentially erasing anything the edge comes into contact with, with zero resistance. If a Q-blade ever breaks, the flying shrapnel will slice through soil and rock, ultimately sinking towards the Earth's core.
  • The Deathstalker handwaves the existence of such blades by explaining that the edge is actually created and maintained by a special force field. Since they can be deactivated, it makes the blades much safer to handle, store, and hide as an assassin's tool.
  • Brazilian novel Espada da Galáxia does it with an extra twist. Not just is the blade that names the book sharpened to a single atom, it's also made of "metallic Hydrogen", making its edge as thin as the smallest atom.
  • In the Firebird Trilogy, the edges of crystaces' blades are precisely one atom thick.
  • The Fountains Of Paradise by Arthur C. Clarke has something very similar to this, but, Clarke being Clarke, it is depicted in a manner closer to scientific reality than most examples on this page. Construction of a Space Elevator becomes a realistic possibility after the development of a process to manufacture a "pseudo-one-dimensional diamond crystal" a few microns thick in continuous lengths, forming invisible fibres of enormous tensile strength. Its main application is as a tension member (of course), not as a weapon, though much attention is given to the handling difficulties and dangers of such a material. Its sharpness is also reasonably realistic—it is extremely sharp, but not absurdly so—it can easily cause severe wounds through mere inattention to handling, but to deliberately cut down a tree with it takes a couple of minutes, and the length of time it takes to cut through a metal fastening with it is an important element at one point in the story.
  • In the His Dark Materials trilogy the Subtle Knife has one edge sharpened so finely that it can cut through any material, the other edge is sharp enough to cut a hole in the universe leading to another one.
  • From the second book onwards in the H.I.V.E. Series series by Mark Walden, Raven fights with a pair of katanas with a variable geometry monomolecular force-field.
  • In Left Behind, Chaim Rozenweig creates a blade like this, so sharp that a falling date splits in two by grazing the blade. He then buries the blade in the head of the leader of the world.
  • The Posleen in John Ringo's Legacy of the Aldenata have monomolecular blades that can carve up an Armored Combat Suit as easy as a Ginzu knife cuts through a tin can. And then they can slice a tomato so thin you can read a newspaper through it!
  • In Daniel Keys Moran's The Long Run, there is the "emblade" (hand-held knife) which goes along with "fineline" (a spool of wire of any length). Both appear to have an edge approximately one molecule wide, allowing them to easily cut through anything. The emblade is useful for cutting holes in walls and floors, because you can simply glue the piece back into place and it is hard to detect. Fineline is useful for putting in front of missile ports, with unfortunate consequences for the missile when it is fired.
  • The main character, as well as just about everyone, in Sergey Lukyanenko's A Lord from Planet Earth series wields a monoatomic sword called a planar sword. The main character, in fact, dual-wields them and carries them on his back. As expected, the swords can cut through any known material. In one-on-one combat with planar swords, one of the swords will invariably slice through the other. The trick is making sure you hit the opponent's sword at just the right angle with a thinner blade. The blade dulls with each strike and swing, requiring it to be periodically sharpened by a button on the hilt (a blade can only handle about 1500 sharpenings). Being a battle-hardened Earthling, the main character comes up with some nonstandard (and questionable) applications for the technology. He creates a throwing disc with monoatomic edges, which can literally take a person's head off. Later, he uses smaller hollow-point monoatomic discs that fire from a blowgun.
  • In Man of the Ice Garden, Vuko Drakkainen, a visitor from future Earth to a primitive planet, uses a Nordland Aeronautics shinobi ken sword with monomolecular blade. He once made a swing at a "monster" and accidentally cut through the ceiling without even noticing until some of its parts fell down. He also accidentally cut through the dog, which hit the ground twice.
  • The Ship Who...: In The City Who Fought, Joat lays a trap using monomolecular wire. The effects are messy.
  • In Snow Crash, by Neal Stephenson, Dmitri "Raven" Ravinoff uses knives made of knapped glass with monomolecular edges. They slash through Kevlar body armor, thick bamboo and people quite effortlessly, though they're still prone to shattering, which is unfortunate as his final opponent just happens to be carrying a sonic weapon.
  • In the first novel The Stainless Steel Rat sees an assassin sneaking into Angelina's room after reeling himself down to her balcony on a monofilament wire. The Rat can't climb down the wire after him as it would slice his fingers off thanks to this trope, and as there's no time for anything else he has to leap off the building and hope he lands on the balcony (it's a long drop if he misses).
  • In the Star Trek Novel Verse, the Tholians have blades with monomolecular edges. The swords become important to the plot in the novels ''The Sundered'' and ''Reap the Whirlwind''.
  • Star Wars Expanded Universe:
    • In the short story "Trip", Jodo Kast, who is actually Thrawn in disguise, gives one to Corran Horn.
    • Blades like this make an appearance in the novel Specter of the Past by Timothy Zahn, in the form of the Xana "molecular stiletto." Depicted somewhat realistically, in that it's described as being capable of cutting through almost anything, but is extremely delicate, with even the carefully executed cutting of a hard surface (such as a lock) being as likely as not to ruin the blade.
  • In the Sten novels, Sten has a small knife in his forearm (within a surgical compartment) that can cut through virtually anything. It's five molecules wide at its tip.
  • Flann O'Brien's The Third Policeman features a spear so sharp that if you were to prick yourself with it, your finger would begin to bleed about 2 inches before the point appeared to reach your finger. In fact, when your finger starts to bleed, the spear point had penetrated your skin 2 inches ago, but was so thin it slipped between the atoms of your finger without causing any damage.
  • Matthew Mantrell wields one in at least the first book of A Wizard in Rhyme. It's also made of a single black diamond. And magic.
  • Wearing the Cape: Repercussions, we see Nike, EU's resident Atlas-Type heroine – homologous to Astra – weilding a glowing leaf-bladed sword and a large Greek hoplite shield, described as having nearly monomolecular edges as grasping vines simply sheared away on contact.

    Live-Action TV 
  • Andromeda once depicted a "monomolecular lash", basically a whip that can cut through anything and has to emit a glow in order for anyone to see it. Since it cuts through its wielder as easily as anything else, it's exceedingly difficult to master without killing yourself with it and expert users of it are very rare, mostly making it Awesome, but Impractical.

    Tabletop Games 
  • R. Talsorian Games' Cyberpunk 2020 had the Monoknife and MonoKatana, both extremely sharp.
  • Dark Conspiracy supplement DarkTek: The Monofilament Machete's blade is 3-4 molecules wide and 1 meter long, with a small red ball on the end so the user can gauge their swing. It can cut through almost any solid substance, including armor.
  • Judges Guild magazine The Dungeoneer Journal #23, article "Magic Item Generator". One of the possible magic items is a Monomolecular Wire that's a single molecule thick. It can cut through any substance but must be anchored at each end to be used as a weapon (e.g. as a garotte).
  • Dungeons & Dragons had psionic powers such as "duo-dimensional blade", which could cut through anything (ignored armor). In the 3rd Edition the power came back as "Deep Impact" (and "Unavoidable Strike" for the unarmed version). A few powers in 4e allowed you to strike against Reflex rather than AC (effectively ignoring armor) and would logically be devastating against anyone relying on heavy armor for protection.
  • Eclipse Phase
    • Monofilament Swords are a common bladed weapon made with self-sharpening smart materials. They easily have some of the highest penetration and damage of any melee weapon in the game. They're still no match for all but the lightest of firearms when it comes to stopping power, though.
    • The 'exotic' Monowire Garrote has the most armour penetration of any melee weapon and inflicts decent damage, although the description notes the wire has fairly low tensile strength and can often break easily.
  • Fading Suns has wireblades — monomolecular swords that will cut through anything with ease. In game mechanics, this means they ignore any armor the opponent is wearing.
  • GURPS Ultra-Tech has a number of (increasingly super-science) ways of working this into the game mechanics. Superfine blades divide damage resistance by two. Monowire blades divide damage resistance by ten. Nanothorn blades divide damage resistance by ten and shreds the bonds that hold the atoms in molecules together.
  • Infinity has monofilament as an ammunition type that is issued almost exclusively to the elite troops of every army. They're not exactly common, but have a nasty effect: anything they hit, if it fails an armor roll, is instantly destroyed and removed from the table, regardless of its remaining wounds or structure. This includes TAGs, named characters, any One-Man Army that might be around. It's hand waved in the background as being stabilized through an EM field.
  • Shadowrun:
    • The game has monomolecular axes that possess a monofilament edge capable of cutting through virtually anything. It tends to lose its edge quickly though. In later editions, other bladed weapons could be outfitted with a monofilament edge. There's also a monofilament whip, noted by 'in character' reviews to be as big a threat to the user as to a potential enemy.
    • At least one supplement had 'consumer annotations' that lampshaded the difference between mere monofilament and a monomolecular filament.
    "Don't believe the hype, kiddies! That's not a real monomolecular filament. After all, my bootlace is monofilament too, and I'm not going to be lopping any limbs off with that."
  • Traveller: In Megatraveller Journal #3, "Worldguide: Vincennes", the Tech Level 16 world Vincennes creates swords of extruded monofilament construction which have astounding penetration.
  • Warhammer 40,000:
    • Monomolecular blades are a fairly common throughout the setting. This includes combat knives, swords, chainsword, some types of ammunition, etc. Counterintuitively it's also stated that one of the reasons for favoring such blades is that they never dull, which makes sense if you don't think about it. These blades are so treasured by the Imperium that a pair of PDF scouts who found a Standard Template Construct printout detailing how to manufacture cheaper and stronger mono-molecular blades were rewarded with a planet, each.
      • Despite fluff books often making it clear how good these are at punching through armour, it's frequently not actually a mechanic in game. One exception is the Dark Heresy (and other Fantasy Flight Games' 40k RPGs), where melee weapons can be upgraded to have monomolecular edges, increasing their armour penetration. In most of the games this can only be done on bladed and chain weapons, but early editions of Dark Heresy didn't have this limitation, allowing any melee weapon to be monomolecular, including hammers and staves. However, the rules stated that an alternative explanation had to be given for the increased penetrative power; there were no monomolecular hammers or staves, they just functioned the same with a different name given to the technology behind it.
    • The various kinds of Eldar are probably the most common users of monomolecular weapons, given that they are generally the most technologically advanced:
      • The most common are "shuriken" weapons. The weapon's magazine is actually a large mostly-cylindrical chuck of matter, and the upper receiver shaves off monomolecular discs. Thousands of them. Per second.
      • Harlequin units have a weapon called The Harlequin's Kiss, which is a hundred-metre-long monomolecular wire, delivered in a neat bundled package with a punch, at which point it unfurls, liquifies the target's internal organs, and then snaps back into the delivery device.
      • Heavier Eldar "spinner" weaponry makes use of "webs" of monofilament cord. They have artillery that sends clouds of this stuff slowly drifting down over the battlefield, invisible until the moment your entire squad falls apart into little chunks.

    Video Games 
  • In the Buck Rogers games, mono(molecular) knives and swords are described in this way. In true RPG fashion, they are superior to most of the 25th-century guns available.
  • The Dragon Tooth Blade from Deus Ex is said to be made of self-organizing nanites which keep the blade always molecularily sharp.
  • Dungeons of Dredmor: The Monofilament Sword is a more typical application of this trope, being a single atom (or thaumaturgon as the game calls 'em) thick, and doing vicious damage. A slightly stranger application is the Moravician Bushdagger, made by the titular (drunk) wizard Moravic on a bet at a pub. The blade starts out normal, then starts branching and branching near-infinitely until every single tip is a single thaumaturgon thick. It stabs a million wounds in one thrust, and is probably the best dagger in the game thanks to it (despite looking like a metallic bush). Unfortunately it also got Moravic banned from the aforementioned pub.
  • The Nanotech Blade in Echoes: Operation Stranglehold is only a few atoms thick at its edge.
  • In Final Fantasy VI, Odin's signature One-Hit Kill movenote  was localized as "Atom Edge," implying this trope.
  • The Avalon WarMech in Implosion wields a sword with a mono molecular edge.
  • Cerberus Phantoms (ninja mooks) in Mass Effect 3 carry monomolecular swords that allow them to do a One-Hit Kill. The player-useable "omni-blades" are equally sharp. These blades increase their practically in two ways: one, the blades are "flash-forged" by high-precision portable fabricators, so they can be renewed as needed; two, they're supported by Mass Effect fields which can also make them Hot Blades.
  • In One Must Fall 2097, the manual describes Thorn's spikes and Katana's blades as using "monofilament technology".
  • A manual for StarCraft states that Ultralisk blades are monomolecular, but this seems to be a case of a writer simply getting carried away with Rule of Cool, as there is no indication elsewhere that this is the case. In game cinematics make you wonder why sharpness would even matter, as their "real" size is shown as far larger than their already large in game models, to the point that their blades are individually larger than things like Terran tanks. They're often shown using their arms more like bludgeons, crushing most targets easily, making actually slicing most things totally unnecessary. It does at least make some sense in game where units are all much closer in size and their attack animations do involve slicing with the blades, though.
  • The retractable blades on the Scorpions in Unreal Tournament 2004 are mentioned to have an edge that is exactly one atom thick. However, while they will instantly cut any on-foot opponent they touch in half, they break off if they touch anything else.

    Web Original 
  • Alton Brown once wrote a short story on his blog about a kitchen apprentice who sharpened a chef's knife until it became one of these...and accidentally set off a nuclear blast while chopping a tomato.
  • Atomic and Subatomic blades in Phaeton
  • SCP Foundation
    • SCP-183 ("Weaver") is a biological entity that creates monofilament wires that can cut through anything up to and including body armor. It uses the wires to kill animals so it can consume them.
    • SCP-314 ("Motion-Seeking Blade"). The blade is described as "sharpened to a molecular level".
    • SCP-585 ("Sharpeners") can do this to pencils. After 100 rotations, the point is so thin that it splits the atoms of the air around it, making the wooden pencil burst into flames and the point impossible to store safely.
    • SCP-608 ("Fractal Tinsel") is a fractal with infinitely and progressively smaller branches radiating from it. Branches of monofilament size and smaller can slice through other substances at a molecular or even atomic level.
    • SCP-1320 ("Refractive Explorers") have extremities that are sharpened to a thickness of a few dozen nanometers. They can use them to cut through solid objects at a molecular level.
  • The long-defunct parody shopping website Villain Supply offered this type of wire for sale as a henchman tool.
  • Things Mr. Welch Is No Longer Allowed to Do in an RPG: "Even if the rules allow it, I cannot have a monofilament sledgehammer."
  • Binder of Shame:
    El Disgusto: “I am sharpening my katana on a mithral whetstone.”
    Me: “Why would you do that?”
    El Disgusto: “So it will be super thin and super sharp.”
    Me: “It will be super broken.”
    El Disgusto: “My character has invented the monofilament blade a thousand years early.”

    Western Animation 
  • In Batman Beyond, Assassin Curare uses a monomolecular sword that effortlessly cuts through anything standing in the way of her swings. During the analysis, Bruce mentions the sword is sharpened by lasers to have an edge as wide as a single molecule.

    Real Life 
  • Contemporary nanotechnology is actually capable of creating blades like this, but, with a few exceptions (see below, mostly), not sustaining them. Regular blades go dull; an edge that can be measured in atoms becomes an ordinary knife very quickly if those atoms do not have very strong atomic and intermolecular bonds.
  • While not quite as far as a single atom, knapped obsidian blades are a small and measurable number of molecules in thickness. And while diamond is the harder material, obsidian can be made sharper. The greatest of care should be used in handling obsidian knives and arrow points etc because they can remain truly Absurdly Sharp even centuries after being made and will cut you badly with even the slightest touch. The drawback of course is that being basically an exotic form of glass, they wear out quickly in use.
    • Obsidian blades are still used in eye surgery when a clean cut is needed.
    • Anthropologists and paleontologists have "tested" the technology available to Stone Age humans by using hand-knapped obsidian blades to butcher an elephant's carcass.
    • Obsidian can be made up to 100 times sharper than steel (the cutting edge can be reduced to 3 nanometers thick). According to The Other Wiki, "even the sharpest metal knife has a jagged, irregular blade when viewed under a strong enough microscope; when examined even under an electron microscope an obsidian blade is still smooth and even." For surgical application, the blades are so sharp that in certain circumstances, no anesthetic is necessary to make the cut. (See here)
    • Many Aztec weapons had obsidian blades or points. The macuahuitl is a wooden sword with the blade made out of obsidian shards. According to Spanish accounts, a single blow from a macuahuitl can decapitate a horse. When they tested it out on Deadliest Warrior, it decapitated the model-horse in three hits and left a pretty big mess.
  • Single-layer graphene is probably the sharpest blade that can be made with conventional matter. It's a single atom thick, and since the atom is carbon (atomic number 6, very low on the periodic table), it's thinner than you can get pretty much any substance without distributed electron orbitals to stiffen it, and it's essentially the strongest material known that operates on that scale. Per unit area, it's stronger than diamond, though diamond is superior at greater thicknesses, due to graphene's weak inter-layer binding.
    • Carbon nanotubes are basically graphene sheets rolled up into a tube, so by definition are a single molecule thick.
    • Graphene monolayer is found to be toxic because the jagged edges they form can pierce cell membrane easily.
  • To prepare a slide for an electron microscope, a diamond or broken glass blade is used to get a less-than-paper-thin slice. Once properly sharpened, it's about a hundred atoms wide, and it will slide through your hand as easily as through the air. Glass blades are sharper (and cheaper) but wear out after a few dozen slides; diamond blades last almost forever if used for their intended purpose; if it slices through your hand, not only are you bleeding horribly, but you'll need a new diamond blade, because cutting through your flesh just broke the damn thing.
  • Best-quality tips of scanning probe microscopes are literally single atom-wide and able to resolve individual atoms of the sample. They are made by laser cutting in the vacuum chambers of the microscopes they are used in, because they're almost impossible to transport without breaking the ends off.

Alternative Title(s): Monomolecular Blade, Sharpened To A Single Molecule