3d printed inflated structures

Hello folks.

I've been using Grasshopper for the last few years as part of my PhD, where i've been developing a 3D printer that can print auxetic (hexachiral) structures on to inflated balloons.

I've made a video showing the entire process. I hope it's of some interest to you all.

https://www.youtube.com/watch?v=Qmuf_6h7Kl8

Replies to This Discussion

Permalink Reply by Nik Willmore on June 19, 2015 at 6:05pm

I'm as impressed by spraying UV cured silicone to create your own balloons as I am by the 3D printing.

Permalink Reply by fergal.coulter on June 22, 2015 at 4:33pm

Oh thanks!

Yes indeed - the spraying wasn't as easy as i expected before i started (when is it ever?!)

I have to use quite a bit of solvent to reduce the viscosity of the silicone so it will atomise. It's quite a slow process (but one that has to be carried out as quickly as possible, so the silicone doesn't cure in the spray gun!)

Permalink Reply by Nick Tyrer on June 22, 2015 at 5:44am

I second everybody else's requests for more information.

It looks fantastic, but I'm afraid i cant work out a logical use to this technique.

Can you remove the print from the balloon and are left with a fabric like flexible object? That has its own unique 'auxetic' behaviour/method of expansion. (that is impossible to create in any other process)

Permalink Reply by fergal.coulter on June 22, 2015 at 4:42pm

I hope my reply above explains this a bit more.

Beyond Dielectric Elastomers, there are uses for printing structures on inflated membranes - particularly in soft robotics, and various medical devices - eg stents like devices.

You can remove the prints on certain occasions - if I cure it quickly after it has been printed (by heat acceleration), it doesn't tend to bond properly to the membrane.

I haven't gotten around to removing a full structure yet - only half printed ones, where things went wrong, so i can't speak for its auxetic behaviour without the balloon. it's quite flexible though, so probably wouldn't act very precisely.

Theoretically one could print ceramic pastes or any kind of paste, then perhaps fire the ceramic, which would vaporise the balloon. I'd like to experiment with that later on - probably purely for aesthetic outputs. (I'm an engineer by trade, but love to play with artistic outputs when i have time!) I'll let you know if I'm ever successful

Permalink Reply by fergal.coulter on June 22, 2015 at 4:48pm

Oh, there's been a few e-zine articles recently, which also explain my process a little more :

3ders.org

3dprint.com

...it's mostly the same as what i've said above, but there might be a bit more info in them (or explain a bit better what i've said earlier!)

Permalink Reply by Nik Willmore on June 22, 2015 at 4:49pm

Euro design prodigy Marcel Wanders of Moooi.com has been making a fortune wrapping resin soaked string around beach balls or whatever he uses:

I believe it took them about three years to make it work, using motion control to wind the string.