The first monomolecular edge blades turn up in the Stone Age as obsidian based prismatic blades, and later in the Atomic Age in glass scalpels used in cardiac surgery. While incredibly sharp, and even used by the Aztecs in construction of the Macuahuitl, they are ineffective at defeating metal based armours - let alone the advanced ceramics of the the 41st millennium. A sharp blade, even one a mere molecule wide at the cutting edge, can not cut through such tough materials.
The monomolecular edge really comes into it own with the development of phase field technologies and the ability to imbue phase into materials, to produce 'phased materials', also know as 'exotics'. Using this technology an advanced ceramic blade, or a metal blade with bonded diamond edge, can be phased to imbue it with unearthly abilities. The most common imparted ability is a 'power field' effect seen in the far more advanced 'power sword' (dealt with below). The power field effect is a phenomena where a material touched by the outside of the field (the blade conducts the field to the surface) is 'softened' as the bonded between molecules are drastically weakened and even negated. This allows a relatively 'fragile' blade to cut through very tough materials with ease.
Imperial (Monomolecular) Blade: This blade can only be processed by the Adeptus Mechanicus. The completed blade, made of mundane materials, is put inside a powerful Phased Field Emitter (PFE) array. The carefully crafted 'phased harmonic' blade's properties are changed and it then produces a local power field effect. The effect is temporary, but the addition of a battery and converter circuits in the handle to supply a constant feed of energy can sustain it. Once the charge in the battery is lost, the power field effect will rapidly dissipate and cease to function, recharging the battery will not reinstate the power field effect. Striking a hard object with a monomolecular blade without it being in a state of phase with seriously damage the edge (as it would be a mundane material once more).
There is a limit to cutting depth as the field's power diminishes with contract, so the 'deeper the cut the lesser the effect'. It is possible to cut so deep into thick armour that the blade becomes stuck and needs a lot of force, or harmonic psionic field, to pull it free (think 'sword in the stone'). Some of the more advanced blades can be synced to a persons latent psionic aura and this actually improves cutting ability to a minor degree (such blades can be passed down through a family, with descendants often having a harmonic aura too). Some Imperial Guard troopers, by chance, have an harmonic aura to the standard issue blade. These individuals find their blades performed exceptionally well, but others have less luck with the exact same weapon. Many myths and superstitions have sprung up to explain this phenomena among the technophobic troopers, most common the idea of Adeptus Mechanicus 'blessing', though 'wytch' is not unknown.
Imperial Power Sword: The weapon is not for general issue, and usually the person wielding it has special dispensation from the Adeptus Mechanicus, with an individual licence. It therefore turns up among the officer class of the Imperial Guard, the higher echelons of the Imperial hierarchy, and the Space Marines. It is an offence for anyone other than the specified licensee to wield the weapon, and the Adeptus Mechanics will seek to reclaim it if they become aware of the contract breach, and usually disable it once within range using their technomancy.
Unlike the monomolecular blade, the power sword actually contains the Phase Field Emitter (PFE) in the hilt and is far more powerful. Having the PFE built in means that if a charge is lost, recharging the power supply with allow the PFE is re-phase the blade (unlike the standard issue monomolecular blade). Power Swords are able to modulate their power output. When the field is compressed (a problem with phased based monomolecular edged weapons), it can increase the power to reinforce the effect. This allows a Power Sword to cut through much thicker armour. Another characteristic of Power Sword are that they can be made far thinner than phased monomolecular blades (though Space Marines seem to love massive blades). Often Power Swords used by officers are Rapier like, some early versions from Earth's Techno-union era are mere 'monomolecular wire' stiffened by the field, and there are rumours of archaeotech Power Swords from the Dark Age of Technology that do not have a physical blade at all - instead using super heated plasma gases and powered by micro-reactors.
No matter the design Power Sword all share the same ability to cut through almost any armour, even some power armours. There are exceptions, and the phased based exotic armours in the Space Marine offer greater resistance than most, but pale in comparison to the Grey Knight's warded anti-psionic armour is virtually immune. It should also be noted that Space Marine flesh is also more resistant to Power Fields than regular human flesh , a minor trace vestige of their Primarch's legacy, though obviously not immune. Power Swords, being a derivative of psionic technologies, can affect lesser daemons.
Generally speaking: a thicker blade is more powerful, and requires less power for the same effect, than a thinner blade - but any loss can be made up by pumping more power into the blade and field. If a field fails, or is ineffective for some reason, then the only power delivered is from the physical blade.
Force Blades: A a further development of this technology. Once tuned to the Psyker wielding the blade, it allows them to channel energy directly into the field. This allows the Psyker to emulate a Power Sword with a super-massive power supply rivalling, and maybe surpassing, the mythical archaeotech blades of the Dark Age. Force Blades are very rare, and can only be used by a Sanction Psyker. A regular person wielding such a weapon with find that are 'underpowered' and handle like a monomolecular blade, and may also induce insomnia, hallucinations and headaches.
Force Blade can affect any class of Daemon, if the Psyker wielding it has sufficient strength to power the blade up to the required level. Some Force Blades, such as those used by the Grey Knights, are attuned to disrupted daemonic aura and links to the warp. Such weapons are incredibly hard to manufacture, as they are attuned to the wielder and attuned to disrupt at the same time, a careful balancing act. The pay-off it that they require far less Psyker energy to rend a daemon, or souls of potent unsanctioned Psykers. Such weapons are the ultimate in Phase Field technology based weaponry.
- Mundane monomolecular edge - notice: fragile edge. (not used as a combat weapon in 40K, used in surgery.)
- Phased monomolecular edge - exotic blade (also known as 'enchanted' in Technophobic and ignorant societies).*
- Power Sword (contains PFE, officer class, requires licence)
- Archaeotech (plasma blade) Power Sword (Adeptus Mechanicus only)
- Force Sword (Sanction Psyker only, require licence)
- This weapon will permanently loose its phase, and become a mundane blade (class 1), if the charge is ever lost. However the blade is much larger than those purposely manufactured mundane monomolecular edge blades (i.e. scalpels) and can be used to slice unarmoured targets much as a Macuahuitl. Any strike to an armoured target will remove the monomolecular edge, and it will then count as a regular blade.
Attunement: All the above, except class 1, can be 'attuned' to the wielder to increase power. The suffix 'a' is added to the class number to denote attunement, so a class 4a phased based weapon could be an attuned archaeotech power sword with inbuilt PFE.
This article may be used as the basis a new page in the Imperial Technology section
Hearing feedback is very important to me in developing my ideas. Much of my designs are inspired, and crafted, by chatting to fans on forums before snowballing into a full concepts posted on this website. I would like to thank all those who have contributed critiques and participated in discussions over the years. If you would like join in, you are most welcome!
To support my work: Connect