3D-manufacturing with biomaterials

[TomV]

Hi all,

I came across this 3D-manufacturing technique, which uses a gel as a suspension material (see video below).It offers a few advantages over regular 3D-printing techniques.
Inspired, I started to wonder if this can be applied into the biofabrication domain.

So, due to my limited knowledge of biology, my question is:
Are there any biomaterials that can cure/harden in the absence of air/oxygen?
By melting, microbial processes, growth processes, symbiosis...
Example: molten (bees)wax could be used to produce some temporary molds or objects.
But perhaps there are far superior bio-resins, composites,bioplastics,... that can be used.
Any ideas?

Some artists use a similar technique to create art inside gelatin.
Perhaps, a controlled, thin film injection (as seen in this videoclip ) following a 3D path could be used to create a seamless 'fabric' item, which would find applications in fashion.

[winnieponcelet]

In my own humble opinion, advanced bio3Dprinting would be revolutionary This is completely @Elise 's domain in her phd!

Not sure about possible materials that answer your question. Perhaps anaerobic bacteria that produce some sort of material... Interested to read other's thoughts.

[Elise]

What is the kind of application you're aiming at with the 3D-printing?
Is it aesthetics (like in the video of the gelatine), then you could use some colourful bacteria or algae (see workshop of Glimps tomorrow: https://www.facebook.com/events/470806270023001/.)
If you'd need more structural, self-standing objects, join the research, cause we're looking for that
There are some applications in medicine. I can send you papers explaining the procedure, but they usually print with cells or bacteria (which are not usable for making structural objects). Until now, all organisms I found to be interesting for biomaterials need air, somehow... but there are a lot of organisms, so it might exist! Corals for example, grow under water...

[Elise]

Talking about coral... some proteins of squids are also used to make materials: https://www.nature.com/articles/srep13482

[TomV]

Hi @Elise ,

I have no particular application in mind, just exploring some possibilities in manufacturing, not aesthetics.
So I'm indeed looking from a structural point of view (as I have a background in industrial design).
But thanks for the info, I'll look into it!

Just a quick idea for your research about creating structures could be this, based on the clip above:

I learned mycelium needs oxygen from a workshop I attended.
Maybe you could extrude a hollow tube inside a gel medium, where the extruded medium could be a paste of hemp fibers and mycelium. The technique could be similar as the videoclip above, so that the gel provides suspension and just enough resistance to battle gravity and prevent oxygen from bubbleing to the surface.

The extruder needle injects air in the center. If the needle can follow a 3D path without the tube collapsing, a mycelium could have an environment where it can grow into a free form 3D structure? If there is not a sufficient amount of trapped air, you could extrude the tube up to the surface of the suspending gel. In that way you have a kind of vent that connects to the air outside the suspension gel and there is a continous acces to oxygen inside the mold.

A needle might be the wrong word, but look a it as it would extrude eg: a 15mm outer diameter tube.

I did not give it some thought or research yet, so there's probably loads of limitations, but who knows

[Elise]

Thanks! This is very interesting matter to reflect on. I was also developing the same idea to add air this way, but with different needles. Print the matter first, then add air bubbles. Your proposal to do it in one needle is intelligent! Only, the tube can collaps, during printing but also afterwards... Unless the airflow is not constant... So you could have a tube that opens and closes.

[TomV]

Yes it could be prone to collapsing during and after printing. But that’s why I thought about using a “paste”. By controlling the viscosity and diameter, you could end up with a stable mixture. Thicker paste and finer diameter could provide just enough stability to prevent deformation under gravity or hydrostatic pressure of the suspension gel.

Another but different idea of 3D-printing without gel could be a hybrid between lost wax casting, and co-extruded FDM 3d printing. You could build up hemp x mycelium paste layer by layer and use (bees)wax as a support material. A tweak to introduce air is to print small holes/channels (“pores”) into the wax layers. The end should be your object, but encapsulated by a wax skin covered with tiny pores.
You can let the mycelium grow until it’s ready.

To finish, you heat up the object, melting the wax (and retrieve for reuse) while also drying your mycelium model.

Maybe that is more feasible?

Limitations will probably be wall thickness of the mycelium, so that the air is evenly distributed within the growing fungus and it grows more predictibly.

[Elise]

You should come one day to the lab at the VUB, so I can show you the infrastructure and the machines we have for 3D printing. I'm sure it will inspire you

[TomV]

That would be cool, let's meet up!