The only related question I have found here is: What would it be like to use a vibro-blade

But would a swung or thrust blade using a high-frequency oscillation actually improve its combat effectiveness? Would the oscillation provide a meaningful increase in cutting/stabbing capability, and if so, against what materials? Would such an increase translate to improved combat effectiveness?


  • Vibrations from this oscillation going back into the handle is no longer a problem.
  • We can somehow generate these high-frequency oscillations in a sturdy material.
  • The weight is somehow reasonably able to be wielded for function; i.e. with not much more difficulty than the 'non-vibro' version.
  • Power supply isn't an issue.

Edit: I am not asking how to make one or how it would 'feel' but if it would be any more effective than a standard swinging blade of the same weight, sharpness, and curvature. The question I linked to never seemed to address this; if it did, I missed that entirely or I wouldn't have asked this question. Looking over it again, I still don't see the answer to my question.

Oh, and "They'd get shot before they could use it." isn't helpful to this question. There are plenty of ways that melee can still be important in fiction.

  • $\begingroup$ There are a lot of engineering challenges, and no benefits that I can think of. $\endgroup$
    – AndreiROM
    Jan 10, 2017 at 18:25
  • $\begingroup$ But the linked question answers the questions you're asking $\endgroup$
    – Aify
    Jan 10, 2017 at 18:47
  • $\begingroup$ I don't really see how this is different from the linked question. $\endgroup$
    – Mołot
    Jan 10, 2017 at 19:30
  • $\begingroup$ @AndreiROM I don't think the linked question answers anything about combat feasibility, that's why I asked. The linked question and it's answers talk a lot about the crafting of such a weapon and the mechanics of how to make it work or how it wouldn't. I never saw anything about how it would perform in battle if you could make it work. $\endgroup$ Jan 12, 2017 at 5:43
  • $\begingroup$ The linked question is about construction and issues with vibration that this question bypasses. $\endgroup$
    – Separatrix
    Jan 12, 2017 at 10:03

3 Answers 3


A vibroblade can make a useful tool, it makes a horrible weapon.

It really doesn't provide any benefit in combat, because most of the vibration will cause movement away from the plane of cut it's just wasted energy. Also because of how short the contact time is during a cut movement (swing) the vibration in any direction that might help will be so minor it won't effect the cut.

If you were going to hold the blade against something and it mostly only vibrates in one plane it will help that is what an ultrasonic cutter does, but then you not talking about a sword you swing, your talking about a saw you press against something and it slowly cuts it, and if they are letting you do that just stab a weak point or shoot them. A vibrosword has to be used slowly to gain any benefit, which makes for a useful tool but a garbage weapon.

Worse yet any force applied to the object being cut is also experienced by the person using the blade, so against a hard material you are mostly just making it bounce around in the wielder's hand because the standing tension in their muscles is less than the force needed to cut the material in the moment of movement, the only way to prevent this is bracing but that takes time so again it makes a horrible weapon.

  • $\begingroup$ The most toollike weapons are anti.-armor devices used on close range by infantry. You may cut through a tank's armor, if you are on it. But. I suspect, a sticky bomb would do better and faster job. $\endgroup$
    – b.Lorenz
    Jan 10, 2017 at 19:01
  • $\begingroup$ One of the assumptions I stated is that the vibrations back to the user is somehow not a problem. But the rest of what you said sounds quite in line with what I was suspecting might be the case. I've edited the question to specify that I am asking for the effectiveness of a swung or thrust blade. $\endgroup$ Jan 12, 2017 at 5:57
  • $\begingroup$ Which I assumed meant the vibration dampening to prevent white finger, but once the blade is exerting significant force against a material That force will be experienced by the wielder, vibration dampening is different then ignoring the laws of physics. $\endgroup$
    – John
    Jan 12, 2017 at 11:23

I can think of 2 circumstances where a vibrating cutting tool might be good. 3 if you count carving turkeys, where they are great.

  1. Low tech. I can imagine kzinti or some warlike race with swords that they slap to make them hum like tuning forks. The idea is that vibration makes them cut better and plus the singing is a bonus - the sword is singing for blood. Some Dexter type can point out that the improvement in cutting conferred by vibration is minimal, and immediately lost as soon as the weapon comes in contact with the opponent. The response is a pat on the head.

  2. High tech. To make this work the tool must generate vibration internally while being held in apposition to the thing being cut. Difficult if the thing you are cutting is wiggling around trying to cut you. I like this for a tool to be used for forced entries, especially in space. There is a range of such tools which opens narrative possibilities when they are used in an ad hoc fashion as weapons. For example I am pretty sure a vibrating tool like this would knock a person out immediately if held firmly against the skull, and might not leave a mark.


I think, that if all the aforementioned issues are solved, vibration will provide increased cutting ability against most materials. If the enemy wears heavy armor, or sits in an armored vehicle, (and your blade is sturdy enough to cut through it without being shattered) it can be useful weapon.

But in modern and future combat, there is a significant probability, that the attacker would get shot while charging at the enemy to vibrostabb him. Therefore vibroblades would be more like tools, allowing the removal of obstacles, pulling down pillars, sabotage stationary objects, etc... without the loud bang of the C4 and in a reusable way.

And there is a fair chance, that the energy invested to power the vibroblade, and the engineering effort to create it would find better use on the battlefields. (Directed energy weapons, exoskeletons, robots...)

  • $\begingroup$ If your blade is not study enough to cut without the vibration it will shatter with the vibration which will put a lot more stress on the blade. $\endgroup$
    – John
    Jan 10, 2017 at 18:39
  • 1
    $\begingroup$ The main limiting factor of cutting ability is the strength of the user, not of the blade. $\endgroup$
    – b.Lorenz
    Jan 10, 2017 at 18:42
  • 1
    $\begingroup$ Ignore my comment, I misunderstood your statement. $\endgroup$
    – John
    Jan 10, 2017 at 18:49

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