like to point out somethings out to you...
wall socket: 120V
Taser: 20,000V
Question: if a taser doesn't kill, why would plugging this thing into a wall socket make it kill you???
it isn't the Voltage that kills you, its the amperage.
the average socket in a house is 15 amps (unless its your kitchen/bathroom GFI/T-slot, then it's 20 amps) People survive discharges of this nature all the time, (someone here must have tried the ol' game of "penny in a lightsocket" or "fork in a receptical"... The main reason why is that while the line can, in theory pull upto 15 amps of current before it trips the breaker, the actual current being drawn is very small. (usually around 20 to 50 mA per light/ receptical)
it takes anywhere from 50mA to 200mA for a fatal shock, and that is hard to do... (unless you lick the BusBar on you fuse box, or grab a transformer, use a resistance inhibiter and touch a live wire, etc)
Also, for the current to be FATAL takes between .2 and 10 seconds (the higher the amperage the faster) for the average receptical output, it wouild take about 3 seconds of continuous contact to enter a state of perminate heart failure. (cardiac arrest).
You would need a LARGE compassitor and a LARGE discharger attached to several transistors (again of HIGH compascity!) made from a low resistive, highly conductive material. (see below)
To be combat worthy, this blade would have to be made of steel (or Ceramic material)... Steel is a poor conductor of electricity, ESPECIALLY carbon steel or Tungsten! Ceramic fiber is a great insolator.
Resistance of common metals/materials
Copper 10.4 (99% pure)
Aluminum 17 (99%pure)
Silver 9.6 (99% pure)
Gold 14.4 (99% pure)
Steel 75
Carbon steel 300** (depending on grade, this number can be 500% higher/lower)
Ceramics 15000** (again depending on materials can be 500% higher/lower)
Human body 300 to 150K** (this depends on a huge amount of factors, some genetic, some personal, my personal resistance with a fluke 11 meter is 57000 ohms can be fun to test if you can get your hands on one)
As you can see Silver is the best metal to use, but it's ductility and malleability makes it a POOR choice for a weapon, and it has to be PURE to maintain that resistance level, start mixing it with other metals and the resistance goes well up.
Electricity follows the shortest path to ground at the speed of light (or, VERY close to it). the discharge would happen the moment the blade came in contact with a grounded, non insolated target and NOT after the blade entered the body.... infact it could discharge upto 3cm AWAY from the target (called "Arcing"), and once the discharge has been made, it will continue to discharge along the same path. Meaning, once it discharges on the shiny zipper of the jacket, pushing it into the body does nothing, the jacket is the discharge point, (and probably has a lower resistance the the human body anyways!)
In short, I could build you this weapon TODAY....
For the nice round price of $25,000 cdn, not including my Labour shop wage of $125/hr. it would take about 3 to 7 seconds of continous contact to kill someone from the electrical discharge, could only be discharged 2 or 3 times, weight in the neighbourhood of 35kg and take about 4 hours to recharge.
or you could stab them to death with a $2.99 walmart butter knife in the same time.