Arduino is at work to make bio-based PCBs | Hacker News Reader

Arduino is at work to make bio-based PCBs

blog.arduino.cc

71 pointsPaulHoule23 comments

From the actual paper: "The resulting yield of PCB production was around 50%. Signal analysis was successful with analogue data acquisition (voltage) and low-frequency (4 kHz) tests, indistinguishable from sample FR4 boards. Eventually, the samples were subjected to highly accelerated stress test (HAST). HAST tests revealed limitations compared to traditional FR4 printed circuit materials. After six cycles, the weight loss was around 30% in the case of PLA/Flax, and as three-point bending tests showed, the possible ultimate strength (25 MPa at a flexural state) was reduced by 80%."[1]

This sort of problem has come up many times with attempts to put some biological filler material into a composite. Most biological materials absorb and release water, and change size and weight as they do. This causes trouble for anything exposed to humidity changes. The classic "hemp/soybean car" ran into this problem.[2] In 1941, plastics were more expensive, and there were attempts to find some cheap material to use as filler. That never got beyond a prototype. Modern attempts at bio-composites seem to hit the same problem.[3]

This might have potential for cheap disposable toys, where expected lifetime is in months and disposal as ordinary trash is desirable.

[1] https://iopscience.iop.org/article/10.1088/1361-6528/ad66d3

[2] https://en.wikipedia.org/wiki/Soybean_car

[3] https://en.wikipedia.org/wiki/Biocomposite

This might have potential for cheap disposable toys, where expected lifetime is in months and disposal as ordinary trash is desirable.

...as if anyone wanted more of that.

I took it to mean they would be biodegradable.

> I took it to mean they would be biodegradable.

The only biodegradable materials are plants and animals. Plastic (however "green") is not. You still get small pieces of plastic from it.

I believe that was the original point: these are plant-based materials so they absorb water which makes them unsuitable for PCBs

> The classic "hemp/soybean car" ran into this problem.[2] In 1941,

Damn, I always thought that Cheech and Chong's hemp car was fiction.

Ford hired George Washington Carver. They heated soybeans to develop a bioplastic.

Soybean car > History, Internet video (of Rollins with a fireman's , Car ingredients: https://en.wikipedia.org/wiki/Soybean_car#Car_ingredients :

> The exact ingredients of the plastic are not known since there were no records kept of the plastic itself. Speculation is that it was a combination of soybeans, wheat, hemp, flax and ramie. Lowell Overly, the person who had the most influence in creating the car, says it was "...soybean fiber in a phenolic resin with formaldehyde used in the impregnation." [16]

What are the binders for aerospace -grade hemp plastic these days? I don't think that formaldehyde is required anymore.

Hempitecture has salt-treated fire retardant hemp batting home insulation product which competes with fiberglass and cellulose batting and fill, and cork.

FWIU treated polyurethane foam (like old seat cushions) absorbs oil (OleoSponge),

Kestrel has a modern vehicle made of hemp plastic.

Name of the 75% hemp aircraft made by Hempearth scientist from Canada doing engineering in the US:

Radar (ROC curve in ML, too) and these days Infrared signatures for hemp vehicles and crafts:

Hemp plastic would have been an advantage in WWII if:

These days many major auto manufacturers use hemp parts in production automobiles for its durability, cost, and sustainability in terms of carbon cost for example.

Hemp bast fiber competes with graphene in ultracapacitor anode applications, and IDK why not normal capacitors and batteries too. Hemp anodes are possibly more sustainable than graphene anodes (in supercapacitors and solid state batteries) due to the environmental and health hazards of graphene production and the relative costs of production.

YouTube has videos of hemp batteries; batteries made of hemp. https://www.youtube.com/results?sp=mAEA&search_query=hemp+ba...

Dimensional Hemp Wood lumber is real, and it is a formaldehye-free sustainable binder FWIU.

So - and this is what Kestrel and Hempearth are going for - it's probably possible to make closer to 100% of a vehicle or an aircraft with biocomposites inspecific or even hemp-only.

> FWIU treated polyurethane foam (like old seat cushions) absorbs oil (OleoSponge),

And Hemp Aerogels are even more oil absorbent than polyurethane foam.

"Hemp plastic door panel sledgehammer test"; History Channel: https://youtube.com/watch?v=Hx8OTH0eEM0&

Re: dandelion (taraxagum) rubber instead of synthetic rubber (plastic) https://news.ycombinator.com/item?id=40892109

Graphene is free when you flash heat unsorted recycled plastic and sell or use the Hydrogen.

Graphene can be produced from CO2.

CO2 is overly-abundant and present in emissions that need to be filtered anyway.

What types of graphene and other forms of carbon do not conduct electricity, are biodegradable , and would be usable as a graphene PCB for semiconductors and superconductors?

Graphene Oxide (low cost of production), Graphane (hydrogen; high cost of production), Diamond (lowering cost of production, also useful for NV QC nitrogen-vacancy quantum computing; probably in part due to the resistivity of the molecular lattice),

How could graphene oxide PCBs be made fire-proof?

Non-Conductive Flame Retardants: phosphorous, nitrogen (melamine,), intumescent systems, inorganic fillers

Is there a bio-based flame-retardant organic filler for [Graphene Oxide] PCBs?

For a moment I thought they were making hobbyist PCBs you can put in your body.

I wonder how it compares to FR-2, an older paper-based PCB substrate. These new bio-based PCBs seem to have some characteristics closer to that than to regular FR-4.

Poorly. PLA has a notoriously low heat deflection temperature, losing nearly all yield strength above about 60ºC. Any 3D printing enthusiast will know that PLA turns into a wet noodle in a hot car. Unless they've made a significant breakthrough in polymer chemistry, this substrate just won't work for the vast majority of applications.

In other words, it's just stupid eco-virtue-signaling at its best.

PLA is too vague to know anything like that about.

There are 100% 'bio' PLA variants with HDT values over 130c+, colorfabb PLA-HP comes to mind.

Polylactic acid is polylactic acid. It has known properties.

I don't know what Colorfabb's PLA-HP filament is actually made of, but it obviously isn't PLA; it's almost certainly some kind of proprietary (and therefore non-recyclable) co-polymer. "Bio-based" is a very different claim to "biodegradable".

and built to last in every sense.

Strong doubt. All this is just greenwashing planned obsolescence to make things self-destruct more quickly, so they can keep selling you more.

Greenwashing - this kind of idea has been floating around for years and I don’t think it’s really that big of a problem

No, we have environmentally and financially unsustainable supply chain dependencies on silicon-grade sand and other gases and minerals.

PCBs are not biodegradable but could be. What is the problem?

You haven't pointed out anything specific to FR4, which is what this would be replacing. This is merely a ploy at getting funding, and I'm very skeptical about it because I've seen 2 or 3 companies do the exact same pitch and fail before.

> The goal: to design and test bio-based multilayer PCBs that reduce environmental impact, without compromising on functionality or performance.

What about cost?

And so instead,

What is a sustainable flame retardant for Graphene Oxide PCBs; and is that a filler?

"Study of properties of graphene oxide nanoparticles obtained by laser ablation from banana, mango, and tangerine peels" (2025) https://www.sciencedirect.com/science/article/pii/S266697812...

Gotta say, I keep wanting these bio-PCBs to be awesome, but tbh the durability stuff always throws me off. Kinda blows when things gotta get tossed every couple months.

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