Semiconductor Filaments?

[LesHall 80]

Hi all,

I am cross-posting the following message from the Lulzbot filament forum to get experts from this Ultimaker forum also in-the-loop. Something tells me that the possibility of 3D printing semiconductors in the home/office environment is just around the corner. Let's at least share some thoughts on the matter...

Les

 

I have been thinking about 3D printing semiconductors for a while now, just occasionally returning to the topic. Then i see this excellent article on the site here:

https://www.lulzbot.com/learn/tutorials/accelerated-aging-your-metal-bearing-3d-prints

And I know that early experimenters in the field of semiconductors used copper oxide (from a wikipedia article), and basically the whole technique of aging metals is making metal rust which is all semiconductors I would guess...

So what if we could make a filament that was a semiconductor in part? Could we make diodes or transistors, even really bad ones?

This time a few minutes ago my mind ran amok with notions of printing a coil of 3mm filament mixing materials like graphene and copperFill, rusting, reprinting, rusting until the desired properties existed.

Or we have PLA with it's low Tc and our bed goes to 120C, can we melt a stick of PLA onto a rusted copperclad board? would that make a diode?

Please advise.

Les

[AreDigg 8]

I don't know if all oxidized metal becomes semiconductors, but of course the MO of CMOS is metal oxide.

Modern semiconductors are now of Si, Al, Ge or Ga and doped to make certain types. As there are already various types of conducting filament, surely it should be possible to create something with semiconducting stuff, however it should also be printable. You have to know the "flow" of the electrons.

[ultiarjan 1,081]

don't know much about semiconductors..... but I tried protopasta's conductive once ...

https://ultimaker.com/en/community/16562-protopasta-conductive-pla

[LesHall 80]

i guess to be clear, my intent is to make ANY semiconductor circuit element, however bad in performance it may be. This is why I refer to early experimentors as their crude techniques with their chosen materials are likely to work together I suppose.

I dream of the day that we can 3D print circuit structures in all manner of shapes and sizes. I know that we can construct logic gates with resistors, diodes, and transistors. As long as the gain of the transistor is greater than the attenuation of the diodes we have sustainable logic elements, or in other words the signals do not decay as they pass from one gate to another.

wouldn't it be cool if we could print a processor cube?

Les

[AreDigg 8]

It is not interesting to have semiconductors. By them selves they are just poor conductors. What you want are like p-type and n-type and be able to combine them to form diodes and transistors. Going by trying to rust old metal particles in PLA feels to me like to study black powder to invent a nuclear bomb. To be honest I think modifying your laser printer will be closer to creating IC's easier than your FDM printer.

However when that said, I could imagine a two-step process by using a plastic extrusion print head which could extrude some semiconducting base-material and in a next process use another "print head" to do something similar to photolithography to turn parts of that layer into a certain semiconducting type.

I know that researchers have created proto-type printers to create electronics, however they are highly specialized and with several processes, and I think it is not viable today to move those into a basic FDM printer.