You’ve heard it before, the future of rapid prototyping will be based on silver ink.
It sounds great in theory, you could essentially get any 3D Printer, replace the filament nozzle with a syringe full of silver nanoparticles and voila!
Sadly, its not that easy. Here’s why:
We’ll go right to it, conductivity of silver nanoparticles is worse than copper. Why you might ask? Imagine having silver particles being suspended in a fluid of some carrier, the particles are sufficiently close so that you can transfer electrons between them, but far enough that it isn’t considered to be jewelry.
Some companies that utilize silver nanoparticles may be using ink similar to DuPont 5021. The value that we are looking for in terms of what describes the low conductivity is sheet resistance.
- Silver nanoparticles has a value of 20mΩ/sq.
- Copper has a value of 0.48mΩ/sq.
Silver nanoparticles is at least 41 times more resistant than copper, this means that you have to be very cautious in your circuit designs, otherwise you will be experiencing voltage drops along the traces. To put this in perspective, lets say you have a trace that is 10 mil wide (i.e. 0.254 mm) and is 1″ long (i.e. 25.4 mm). Furthermore, lets say you are pushing only 100 mA, at the end of the trace you will have a 200 mV drop. That is very substantial.
It might work
Where it might work is when the ink is baked at a very high temperature, but this processes is very expensive, and crucial to achieving low resistivity comparable to copper.