A 32-bit processor made with an atomically thin semiconductor
42 comments
·April 8, 2025ohazi
chmod775
They do mention SERV in their references (38).
https://www.nature.com/articles/s41586-025-08759-9
Sadly I can't access the full article right now.
koverstreet
That sort of copying without attribution should be considered outright misconduct; it certainly would be in academia.
lambda
Huh? This is a paper published in Nature, and it does cite Olof Kindgren and SERV in the references: https://www.nature.com/articles/s41586-025-08759-9#Bib1
The paper itself is behind a paywall so I can't see it, but it looks from the references like they provided proper attribution.
It's unfortunate that some of the articles around it don't mention that, but it seems like the main point of this is discussing the process for building the transistors, and then showing that can be used to build a complete CPU, not the CPU design itself which they just used an off-the-shelf open source one, which is designed to use a very small number of gates.
reaperman
> The paper itself is behind a paywall so I can't see it
lelandbatey
Thanks to the Archive.org link, we can see that indeed they link directly to the SERV github in reference 38:
38. Kindgren, O. et al. SERV - The SErial RISC-V CPU. GitHub http:/github.com/olofk/serv (2020).null
inverted_flag
[flagged]
amelius
I'm still waiting for that inkjet printer that can print transistors.
godelski
Has anyone tried to replicate this? Seems like it would be very useful for amateur makers/hackers were it not for the $23k printer cost (no idea for the cost of the discussed silver ink). But surely someone crazy had access to one and tried or has tried to replicate on a cheaper printer? I figure HN has a decent chance of helping find said persons?
philipkglass
It's possible that the inkjet printed transistor is both replicable and impractical for building a full microprocessor.
The inkjet transistor article says "A total of 216 devices were tested with a yield of greater than 95%, thus demonstrating the true scalability of the process for achieving integrated systems." But 95% yield on the transistor level implies vanishingly low yield at the device level when you need thousands of transistors to build a full microprocessor.
Even the new MoS2 microprocessor discussed in the Ars article wasn't fabricated all at once. It was built up from sub-components like shift registers containing fewer transistors, then those components were combined to make a full microprocessor. See for example "Supplementary Fig. 7 | Yield analysis of wafer-level 8-bit registers." in the supplementary information:
https://static-content.springer.com/esm/art%3A10.1038%2Fs415...
The yield of 8-bit registers, each consisting of 144 transistors, can reach 71% on the wafer.
godelski
My knowledge of transistors is pretty limited[0]. Does the yield percentage refer to number of successful chips on a substrate or look more at the total number of successful transistors? (Or confusing hybrid-term like rain forecasts) I believe your comment implies the latter? So the number of successful processors is quite low? How many failed transistors can you have in a working microprocessor? (Probably not an easy to answer question?)
[0] Am I remembering correctly that this is your area?
exe34
if you could print transistors, you could make computers the way Wozniak made them - a bunch of chips with a ton of wiring.
superb_dev
I don’t think they’ve tried it yet, but it’s seems up the alley of Applied Science on YouTube
godelski
I'm not sure this is Ben's forte, but you're right that I wouldn't be surprised if he tries it, though he has done some circuit stuff[0,1] so nothing would surprise me from him. (Hi Ben! Love the work!) BUT I do think this is something Sam Zeloof[2] try. He's done some lithography using a projector[3]. Also there's Jeri Ellsworth, but I think she's shifted to mostly working with her AR project. Tons of old videos on that stuff if you're into it.
Side note: I'm assuming anyone who knows any of these people would be interested that a new Dan Gelbart video just dropped[5]!
-----------------------------------------
[0] https://www.youtube.com/watch?v=UIqhpxul_og
[1] https://www.youtube.com/watch?v=FYgIuc-VqHE
[2] https://www.youtube.com/@SamZeloof
[3] https://www.youtube.com/watch?v=XVoldtNpIzI
bombela
I am building one. Right after I find out where to buy liquid semi-conductor paste.
lsllc
If it's anything like regular InkJet printers, the liquid semiconductor would paste be all dried up every time you went to use it, or the capacitor cartridge would run out long before the resistor one did!
/s
neuroelectron
Intel and CEA-Leti Collaboration:
Intel and the French research institute CEA-Leti are jointly developing 2D transition-metal dichalcogenides (TMDs), such as molybdenum disulfide (MoS₂) and tungsten-based materials, for integration into 300mm wafers. These materials offer sub-1nm transistor channel thickness, making them ideal for extending Moore's Law beyond 2030.
gcanyon
Since it's a single-molecule thick, could this potentially be stacked thousands, or millions, thick to deliver ridiculous capacity? I assume heat dissipation would be a factor, but the article doesn't mention it.
gcanyon
> It's slow and inefficient
Is there any reason to think this won't improve with time? The Intel 4004 was "slow and inefficient" too?
mikewarot
I wonder if Sam Zeloof and Atomic Semi are trying this out? It would be an excellent match for their "build in one atom at a time" approach.
metalman
I like where they say "a sheet that is only a bit over a single atom thick, due to the angles between its chemical bonds" it's funny that material science has achived ultimate precision, but it can only be talked about in general terms Is there any exact way to describe the thickness of molebdium disulfide sheets?, beyond "a bit over one atom thick" clearly they are etching parts of the sheet, and somehow attaching leads, but is it done strictly in two dimensions, ie: litteral, flat land?
fc417fc802
> Is there any exact way to describe the thickness of molebdium disulfide sheets?
It's the same set of issues that you'll run into if you try to precisely quantify the thickness of a sheet of printer paper. It really depends on what you mean when you ask the question. The geometry of the electron shell, the minimum theoretical width once assembled into the theoretically optimal sheet, the impact of various imperfections in practice, the potential for more than a single layer to exist (and the associated averages), and a number of other things that aren't immediately coming to mind.
It's an issue of precision on the part of the party asking the question. We usually work on scales that are so large that such details aren't meaningful (if you can even measure them in the first place).
roywiggins
Looks like a monolayer is about a nanometer thick.
https://www.acsmaterial.com/monolayer-molybdenum-disulfide.h...
ChrisGammell
What is this, a MCU for ant(man)?! It needs to be at least...three times that thick!
I suspected that this was the case when they mentioned adding "one bit at a time" -- the CPU design that they implemented is Olof Kindgren's SERV [0], a tiny bit-serial risc-v CPU/soc (award-winning, of course).
From [1]:
> Olof Kindgren
> 5th April 2025 at 10:59 am
> It’s a great achievement, but I’m of course a little sad to see that it’s not mentioned anywhere that Wuji is just a renaming of my CPU, SERV. They even pasted in block diagrams from my documentation.
[0] https://github.com/olofk/serv
[1] https://www.electronicsweekly.com/news/business/2d-32-bit-ri...