Conductive Flexible TPU Filament

Talk about materials used in 3D printing

Conductive Flexible TPU Filament

Postby ktfergus » 2016-Nov-Sat-16-Nov

I began looking around today to see if anyone made a conductive TPU filament for a product I've been working on; an adaptive stylus. I've found two suppliers so far: Palmiga which looks promising, but the entire check out page is in Swedish, & there's Black Magic 3D but I don't want to pay $45 for a measly 100g.

Does anyone know where else I might be able to get my hands on a roll of Conductive TPU?

-Kelly
  • 0

PrintrBot Model: 1403 (Simple Metal Assembled) :: DIY Heated Bed, with 305mm Extended X Axis
PrintrBot Model: 1403 (Simple Metal Assembled) :: 305mm x200mm DIY heated bed
PrintrBot Model: 1505 (Play) :: 100mm x 250mm DIY heated bed
Latest Project: Flux Capacitor
User avatar
ktfergus
Waiting for printbed temp...
 
Posts: 140
Joined: 2015-Jan-Thu-14-Jan
Location: Los Osos, CA
Reputation: 15

Conductive Flexible TPU Filament

Sponsor

Sponsor
 

Re: Conductive Flexible TPU Filament

Postby RetireeJay » 2016-Nov-Sat-21-Nov

Several years ago, I was trying to find conductive epoxy (no, not for 3D printing, and not flexible). The best that I could find was extremely expensive, and even at that it wasn't particularly a good conductor. Basically, it was an epoxy mixed with a high proportion of finely-ground silver, which accounts for the expense.

I've heard that there are organic (i.e. plastic) conductors nowadays, and carbon nanotubes can be conducting, but I doubt you'll find an inexpensive, flexible plastic that's anywhere close to being a good conductor of electricity. And as the plastic flexes, expect the quality of conduction to vary with the deformation and also have residual changes after the deformation is over. It's a really tough problem, and if anyone does come up with a very cheap and reliable way of making excellent electrical conductors that are truly flexible, expect a huge explosion of applications in smart clothing, automation robots, etc. etc. Since we don't see that right now, that tells you the problem hasn't been cracked.

I recommend instead using standard plastics and then conductive paints or very fine springs to minimize your expense while achieving some degree of conduction.
  • 0

Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
User avatar
RetireeJay
My next printer is...
 
Posts: 4776
Joined: 2013-Jan-Wed-13-Jan
Location: Greenville, SC
Reputation: 477

Re: Conductive Flexible TPU Filament

Postby ktfergus » 2016-Dec-Thu-19-Dec

I recommend instead using standard plastics and then conductive paints


I considered doing just that, initially, but then I came across conductive PLA which worked well for my needs.

Just in case anyone is interested, I brushed up on my Swedish & purchased half a kilo of the conductive TPU from Palmiga. With shipping & the exchange rate it ended up costing around $75. At that price, I'm happy & relieved to report the stuff really works! It prints & behaves just like regular TPU or Ninja Semiflex. It's not a perfect conductor, obviously, but it does the job for my application.

Up to this point, I've been using conductive PLA on one half of each stylus with a TPU part bolted onto it to obtain an adjustable fit. However, conductive PLA is even more brittle than regular PLA & I was never completely satisfied with the layer adhesion. Plus, I still had to print & attach that second part. Now the whole thing is conductive TPU.

Here's the final product:
Image

I had hoped to eliminate the nib & print the entire stylus in TPU but I found that you need a fairly large cross section/surface area to get a captivate screen to react to the conductive TPU.

-Kelly
  • 1

PrintrBot Model: 1403 (Simple Metal Assembled) :: DIY Heated Bed, with 305mm Extended X Axis
PrintrBot Model: 1403 (Simple Metal Assembled) :: 305mm x200mm DIY heated bed
PrintrBot Model: 1505 (Play) :: 100mm x 250mm DIY heated bed
Latest Project: Flux Capacitor
User avatar
ktfergus
Waiting for printbed temp...
 
Posts: 140
Joined: 2015-Jan-Thu-14-Jan
Location: Los Osos, CA
Reputation: 15


Return to Material talk

Who is online

Users browsing this forum: No registered users and 1 guest