Monomolecular Wire
Tech Level: 14
Monomolecular Wire Whip
Tech Level: 14
Variable Sword
Tech Level: 23

Monomolecular wire is a strand of filament, often microscopically thin, created from a single unbroken chain of molecules. They are also called monofilaments (not to be confused with real life material used in fishing lines) or microfilaments.

Tech Level: 14

Monomolecular wire is found in numerous science fiction works, including the "Known Space" stories of Larry Niven, Stand On Zanzibar by John Brunner, and many cyberpunk sources. The latter includes the works of William Gibson, the movie "Johnny Mnemonic" (based on a Gibson story,) and tabletop RPGs such as Cyberpunk

No matter the source, monomolecular wires share two common characteristics:

One, they are almost always possess extremely high tensile strengths (often at the level of diamond or higher) and are very tough to break. But despite this, they are still as supple and flexible as normal copper or steel wire, sometimes more so.

Two, they are always extremely thin, sometimes barely visible to the human eye, sometimes microscopically invisible (literally a single molecule wide.)

How exactly one could manufacture a single molecule so immensely huge is unknown. However, hints may be found in both crystaline structures such as diamond and repeating lattices such as carbon nanotubes. It may be possible with advanced computer modeling to figure out how modify these substances or to discover new molecular chain configurations that can be repeated over and over without falling apart.

Creating monomolecular wire will also require sophisticated nanoscale manufacturing capabilities. Nanoscale manufacturing allows engineers to create a material literally atom by atom and molecule by molecule using extremely precise industrial tools as well as sophisticated chemical processes. This technology is in its infancy today, but when it will finally gear up for true large-scale applications (estimated at around Tech level 14), monomolecular wire may be the first of its products to reach wide spread use. (If its possible to make at all, of course.)

The wire’s extremely thin profile, combined with its extraordinary strength, leads to the use in which its most often depicted: as a cutting tool. Its thinness actually makes it keener than the sharpest possible knife’s edge, and its tensile strength means they’re very difficult to break under tension. As such, they can cut through almost any normal material if the wire is held taut and pushed or pulled through.

In fiction, they’re usually depicted as being able to slice through most normal materials with little or no resistance, including wood, stone, concrete, plastic, cloth, bone, flesh, and low-grade metals, among others. In some sources, such as the ‘Sinclair molecule chain’ in Niven’s stories, the wire is so impossibly thin it actually slips between the molecules of other substances to cut it, and under tension will pass through them as easily as normal wire passing through water.

Materials approaching or surpassing the tensile strength and hardness of the wire, and some materials with unusual properties, may slow down, hamper, or halt the cutting process altogether. Some substances won’t be able to be cut at all. Diamond and carbon nanotubes, already mentioned, would be two such substances that would resist being cut, as would other monomolecular materials. Certain advanced polymers and alloys may also be difficult to cut through and require an active sawing motion.

Any of these cut-resistant materials may be used to spool and handle the thread. In fact, it is usually the hardness of the spool that determines just which substances can be cut. When force is applied, if the substance to be cut is softer than the spool material, the target substance will be cut. However, if the substance to be cut is harder than the spool material, the wire may cut into the spool instead, ruining it.

Monomolecular wire would ideally be handled by an automaton, but in fiction its often depicted as a human-ready tool, with spools being built into easy-grip handles that are pulled apart. Sometimes one end of the wire is attached to a widget that is designed to be anchored down on a surface, such as a floor or a wall. Sometimes the spools will come with specialized cutting and mounting tools that allow a user to cut and attach variable lengths to different surfaces.

Monomolecular wire may also be carried and used covertly, in which case the spools will be disguised as more mundane items, such as buttons on clothing, in shoe heels, or firearm handles.

As once can imagine, monomolecular wire can be very hazardous to handle by hand. One wrong twist or flip of the hand could result in severed fingers or wrose, and the cut would be so clean the person may not even notice it at first. Handlers, even if wearing protective gloves and clothing, would have to practice extreme caution when handling such a potentially dangerous item.

Monomolecular wire would have other uses, depending on the exact nature of the molecule chain used to create it. In Niven’s "Known Space" stories, for example, they were used both as super-strong tethers and as superconducting wires. Depending on a wire’s exact electrical and physical properties, they could also be used in integrated circuitry, as embedded fibers in clothing for proof against certain types of weapons, and so on.

Tech Level: 14

A potentially devastating melee weapon, a monomolecular whip was seen in the short story and movie version of Johnny Mnemonic and various cyberpunk RPGs, such as Shadowrun and Cyberpunk

It is similar to a normal monomolecular wire spool, but one end of the line is attached to a small weight that will pull the line taught when it is swung or spun. If the wire is spooled out to sufficient length (usually 2-3 meters, sometimes longer), a skilled user can swing it around to cut through opponents and obstacles, as the speed and tension of the wire would ensure it would be able to easily cut through almost anything in its path.

This would be a slashing weapon only. It could not be used to drill holes in a flat surface. If the wire cannot wrap around or slash across the object, with won’t be able to affect it.

While these can be very devastating weapons to use at close quarters, they are also supremely dangerous to the user as well as to potential targets. Anyone who has handled even a normal whip can attest to how difficult it can be to wield them with precision, with a variable-length whip made of invisible wire it could be much worse than even that. One even minor slip could result injury or worse to the user, especially if he or she is not wearing cut-proof materials. Obviously, these weapons would only be used by the truly reckless or the highly-skilled.

In order to help a potential user wield monomolecular whips more effectively, manufacturers could work in several features to help them visualize where the wire would be at any given moment. The weighted end might be painted brightly or with contrasting colors, or it could even glow with an LED. In the movie version of Johnny Mnemonic, the monofilament weapon was constructed in such a way that the wire was able to glow bright red when a small current was run through it.

Tech Level: 23

A variable sword is an ultra-tech update of the monomolecular whip, seen in numerous "Known Space" stories and novels by Larry Niven. The weapon consists of a sword-like handle and a bright, glowing red ball, both attached by a variable length of monomolecular wire.

Like with a monomolecular whip, the wire can spool out to various lengths, in this case from a few centimeters to ten or twenty meters or more. However, with a variable sword, the wire is held perfectly—and immutably—rigid by a stasis field that conforms itself around the molecule-thin wire.

Within the stasis field, the wire goes from very tough to literally indestructible, as very little in the outside universe save gravity can affect it. It cannot be bent or curved in anyway, and is thus held perfectly taut along its entire length. The ‘blade’ of the sword is also of near-negligible weight, with the indicator ball making up most of its mass.

The user can literally slash through any normal material that’s smaller than the sword’s current length. Unlike with a whip, however, the wire stays perfectly straight and with its glowing red indicator ball, its fairly easy to tell where exactly it is. Like the monomolecular whip, though, it is incapable of thrusting attacks.


In Print

Virtual Light and "Johnny Mnemonic", both by William Gibson

Cyberpunk et al

Shadowrun, et al



Article added 2/11/10