5 ms·

Reading the article, it looks like so far they only have a working resettable fuse (a passive device), and only hypothesize that a transistor was possible with

by jayyhu 2y ago

Reading the article, it looks like so far they only have a working resettable fuse (a passive device), and only hypothesize that a transistor was possible with the copper-infused PLA filament. So no actual working active electronics. And from the paper linked in the article[1], it seems the actual breakthrough is the discovery that copper-infused PLA filament exhibits a PTC-effect, which is noteworthy, but definitely not "3D-Printed Active Electronics" newsworthy. [1] https://www.tandfonline.com/doi/full/10.1080/17452759.2024.2404157#d1e604 https://www.tandfonline.com/doi/full/10.1080/17452759.2024.2...

greenavocado 2y ago
> So no actual working active electronics. Oh so this is another scam like the MIT Food Computer. At this point I assume everything coming out of MIT is a scam until independently validated by disinterested third parties
- frognumber 2y ago
  This shouldn't be a downvote or flag. It's a serious problem, especially at elite institutions, and especially at MIT and Stanford. It's also not out-of-line with what credible sources observe: https://blogs.bmj.com/bmj/2021/07/05/time-to-assume-that-health-research-is-fraudulent-until-proved-otherwise/ https://blogs.bmj.com/bmj/2021/07/05/time-to-assume-that-hea... I'm affiliated with MIT, and have been for the vast majority of my life, including at points in fairly senior roles. If you shut people out pointing problems, it will never get better. There's an incredible urge to defend elite academic institutions, but it's not in the interest of those institutions. Remember your civics class (patriots criticize their government institutions). The only way I see this fixed involves a period where MIT is viewed like a used car salesman in the public eye for at least enough years to cause enough pain to lead to reform. The endowment is big enough it'll do fine in the end. If it keeps sliding to fraud, it won't.
hatsunearu 2y ago
usually even these academia hype pieces have some grain of utility but this one was so incomprehensibly bad that i was genuinely confused if i'm reading it incorrectly. what the hell?
IanCal 2y ago
Hang on, can you explain why this is passive and not active? > Harnessing the described phenomenon, we created the first semiconductor-free active electronic devices fully 3D printed via material extrusion. We demonstrate this breakthrough through the implementation of monolithically 3D-printed logic gates.
- magicalhippo 2y ago
  They've created a Polymeric Positive Temperature Coefficient (PPTC) device. As it heats up the resistance gets very high very abruptly. While it is non-linear, diodes are also considered passive devices[2], as active is taken to mean electrical control of current flow. In this case one could induce current control through thermal means, ie an adjacent heating element, and if you potted that in a box I guess you could argue the box is an active device. But not the PPTC itself. [1]: https://m.littelfuse.com/~/media/electronics/technical_papers/resettable_ptcs/littelfuse_fundamentals_of_resettable_functionality_in_pptc_devices_technical_paper.pdf.pdf https://m.littelfuse.com/~/media/electronics/technical_paper... [2]: https://wiki.analog.com/university/courses/electronics/text/chapter-1#active_versus_passive_devices https://wiki.analog.com/university/courses/electronics/text/...
  - amelius 2y ago
    > active is taken to mean electrical control of current flow Is a transformer an active device? Asking because current in one loop can control current in the other loop. From there, are two copper wires an active device?
    - adrian_b 2y ago
      The current in one transformer loop does not control the current in the other loop. The power from one loop is transferred into the other, there is no control. The same for two copper wires. "Control" means that you can determine the value of the power in some circuit by consuming less power to do this. If you have to use the same power, not less, then you are the provider of power, not someone in control, i.e. this is the difference between bosses and the workers commanded by them. The bosses do not lift heavy parcels themselves, they order to some worker to do that. A device that apparently looks like a transformer but it is an active device is the magnetic amplifier. There are 2 differences from a transformer, the magnetic core is saturable during normal operation (any magnetic core is saturable at a high enough magnetic field, but when that happens in a transformer this means that the transformer has failed, which leads to overcurrents that would destroy the equipment unless a protection is triggered), and the second difference is that the control coil has a very high number of turns, so that a very small current can saturate the magnetic core. In a magnetic amplifier, the output coil is inserted in an AC circuit where the power must be controlled. When the core is not saturated, the impedance of the coil is high and the output AC current is low. When the core is saturated, the impedance of the coil is low and the output AC current is high. Whether the magnetic core is saturated or not is controlled with a very small current and power on the control coil, which makes this an active device. Magnetic amplifiers have been heavily used during WWII, especially by the Germans, who had improved them, and they continued to be used for a few decades after the end of WWII, when USA had captured the German technology, because of their very high reliability, until the transistor amplifiers have become reliable enough.
bee_rider 2y ago
Well, it is just “a step.” Whether or not it is newsworthy… eh, I mean, what is MIT News? A campus newspaper? I’m pretty sure we had articles on particularly big games of capture the flag in mine.
- throawayonthe 2y ago
  [dead]
- jayyhu 2y ago
  It looks like the editors have amended the title of their article since this was initially posted. The original title was just “3D-printed Active Electronics”
- notjulianjaynes 2y ago
  What seems cool about this to me is that they seem to have done it with a plain old FDM printer and copper impregnated PLA. The devices are fairly large (mm scale) so presumably anyone with a $200 ender and the correct filament could print these. I am able to find copper PLA for sale too, although I'm not positive it is what was used in the experiment, and it's kind of pricey (~ $100/kg).
atoav 2y ago
Not to be that guy, but this is a typical situation as it occurs a thousand times per week: 1. Scientists make minor progress as part of a multi-year effort, release a paper, paper features overly optimistic outlook to get future funding 2. Institute marketing department both hypes it up and dumbs it down a little 3. Popular science press picks it up and both hypes it up and dumbs it down a little more 4. Scientific literate readers read it and complain TL;DR: Nothing new under the sun
jayyhu 2y ago
I want to clarify that they actually did build a transistor-like device, and not just hypothesize about it. I missed section 3.2 when I initially skimmed the paper, which demonstrates and shows the results of a working “transistor”. Unfortunately I can’t edit my original post, so apologies for causing any confusion.
- deleted 2y ago
  [deleted]
- netrap 2y ago
  This image shows logic gates they made: https://www.tandfonline.com/cms/asset/5043deae-e79e-45fc-bb7e-060c31599873/nvpp_a_2404157_f0005_oc.jpg https://www.tandfonline.com/cms/asset/5043deae-e79e-45fc-bb7...
- nativeit 2y ago
  It’s cool for tinkering, and I think there are lots of potential use-cases for conductive filaments and printing in electronics, but I don’t think transistors are necessary. Silicon crystal development is really already a sort of “additive manufacturing”, and I’m not sure what purpose would be served by re-inventing a method that would be starting so far behind in terms of scale, precision, and cost in relation to traditional semiconductor production (anyway, I assume this idea is broadly for learning/experimentation/the lols, rather than some earnest aspiration for using metal-bearing printer filaments to produce active components).
  - mycall 2y ago
    What about the use of power transistors that don't too well as silicon crystals afaik.
westurner 2y ago
From https://news.ycombinator.com/item?id=40759133 https://news.ycombinator.com/item?id=40759133 : > In addition to nanolithography and nanoassembly, there is 3d printing with graphene. And conductive aerogels, and carbon nanotube production at scale From https://news.ycombinator.com/item?id=41210021 https://news.ycombinator.com/item?id=41210021 : > There's already conductive graphene 3d printing filament (and far less conductive graphene). Looks like 0.8ohm*cm may be the least resistive graphene filament available: https://www.google.com/search?q=graphene+3d+printer+filament+ohms https://www.google.com/search?q=graphene+3d+printer+filament... > Are there yet CNT or Twisted SWCNT Twisted Single-Walled Carbon Nanotube substitutes for copper wiring? Aren't there carbon nanotube superconducting cables? Instead of copper, there are plastic waveguides

by jayyhu 2y ago

greenavocado 2y ago

> So no actual working active electronics. Oh so this is another scam like the MIT Food Computer. At this point I assume everything coming out of MIT is a scam until independently validated by disinterested third parties

frognumber 2y ago
This shouldn't be a downvote or flag. It's a serious problem, especially at elite institutions, and especially at MIT and Stanford. It's also not out-of-line with what credible sources observe: https://blogs.bmj.com/bmj/2021/07/05/time-to-assume-that-health-research-is-fraudulent-until-proved-otherwise/ https://blogs.bmj.com/bmj/2021/07/05/time-to-assume-that-hea... I'm affiliated with MIT, and have been for the vast majority of my life, including at points in fairly senior roles. If you shut people out pointing problems, it will never get better. There's an incredible urge to defend elite academic institutions, but it's not in the interest of those institutions. Remember your civics class (patriots criticize their government institutions). The only way I see this fixed involves a period where MIT is viewed like a used car salesman in the public eye for at least enough years to cause enough pain to lead to reform. The endowment is big enough it'll do fine in the end. If it keeps sliding to fraud, it won't.

hatsunearu 2y ago

usually even these academia hype pieces have some grain of utility but this one was so incomprehensibly bad that i was genuinely confused if i'm reading it incorrectly. what the hell?

IanCal 2y ago

Hang on, can you explain why this is passive and not active? > Harnessing the described phenomenon, we created the first semiconductor-free active electronic devices fully 3D printed via material extrusion. We demonstrate this breakthrough through the implementation of monolithically 3D-printed logic gates.

magicalhippo 2y ago
They've created a Polymeric Positive Temperature Coefficient (PPTC) device. As it heats up the resistance gets very high very abruptly. While it is non-linear, diodes are also considered passive devices[2], as active is taken to mean electrical control of current flow. In this case one could induce current control through thermal means, ie an adjacent heating element, and if you potted that in a box I guess you could argue the box is an active device. But not the PPTC itself. [1]: https://m.littelfuse.com/~/media/electronics/technical_papers/resettable_ptcs/littelfuse_fundamentals_of_resettable_functionality_in_pptc_devices_technical_paper.pdf.pdf https://m.littelfuse.com/~/media/electronics/technical_paper... [2]: https://wiki.analog.com/university/courses/electronics/text/chapter-1#active_versus_passive_devices https://wiki.analog.com/university/courses/electronics/text/...
- amelius 2y ago
  > active is taken to mean electrical control of current flow Is a transformer an active device? Asking because current in one loop can control current in the other loop. From there, are two copper wires an active device?
  - adrian_b 2y ago
    The current in one transformer loop does not control the current in the other loop. The power from one loop is transferred into the other, there is no control. The same for two copper wires. "Control" means that you can determine the value of the power in some circuit by consuming less power to do this. If you have to use the same power, not less, then you are the provider of power, not someone in control, i.e. this is the difference between bosses and the workers commanded by them. The bosses do not lift heavy parcels themselves, they order to some worker to do that. A device that apparently looks like a transformer but it is an active device is the magnetic amplifier. There are 2 differences from a transformer, the magnetic core is saturable during normal operation (any magnetic core is saturable at a high enough magnetic field, but when that happens in a transformer this means that the transformer has failed, which leads to overcurrents that would destroy the equipment unless a protection is triggered), and the second difference is that the control coil has a very high number of turns, so that a very small current can saturate the magnetic core. In a magnetic amplifier, the output coil is inserted in an AC circuit where the power must be controlled. When the core is not saturated, the impedance of the coil is high and the output AC current is low. When the core is saturated, the impedance of the coil is low and the output AC current is high. Whether the magnetic core is saturated or not is controlled with a very small current and power on the control coil, which makes this an active device. Magnetic amplifiers have been heavily used during WWII, especially by the Germans, who had improved them, and they continued to be used for a few decades after the end of WWII, when USA had captured the German technology, because of their very high reliability, until the transistor amplifiers have become reliable enough.

bee_rider 2y ago

Well, it is just “a step.” Whether or not it is newsworthy… eh, I mean, what is MIT News? A campus newspaper? I’m pretty sure we had articles on particularly big games of capture the flag in mine.

throawayonthe 2y ago
[dead]
jayyhu 2y ago
It looks like the editors have amended the title of their article since this was initially posted. The original title was just “3D-printed Active Electronics”
notjulianjaynes 2y ago
What seems cool about this to me is that they seem to have done it with a plain old FDM printer and copper impregnated PLA. The devices are fairly large (mm scale) so presumably anyone with a $200 ender and the correct filament could print these. I am able to find copper PLA for sale too, although I'm not positive it is what was used in the experiment, and it's kind of pricey (~ $100/kg).

atoav 2y ago

Not to be that guy, but this is a typical situation as it occurs a thousand times per week: 1. Scientists make minor progress as part of a multi-year effort, release a paper, paper features overly optimistic outlook to get future funding 2. Institute marketing department both hypes it up and dumbs it down a little 3. Popular science press picks it up and both hypes it up and dumbs it down a little more 4. Scientific literate readers read it and complain TL;DR: Nothing new under the sun

jayyhu 2y ago

I want to clarify that they actually did build a transistor-like device, and not just hypothesize about it. I missed section 3.2 when I initially skimmed the paper, which demonstrates and shows the results of a working “transistor”. Unfortunately I can’t edit my original post, so apologies for causing any confusion.

deleted 2y ago
[deleted]
netrap 2y ago
This image shows logic gates they made: https://www.tandfonline.com/cms/asset/5043deae-e79e-45fc-bb7e-060c31599873/nvpp_a_2404157_f0005_oc.jpg https://www.tandfonline.com/cms/asset/5043deae-e79e-45fc-bb7...
nativeit 2y ago
It’s cool for tinkering, and I think there are lots of potential use-cases for conductive filaments and printing in electronics, but I don’t think transistors are necessary. Silicon crystal development is really already a sort of “additive manufacturing”, and I’m not sure what purpose would be served by re-inventing a method that would be starting so far behind in terms of scale, precision, and cost in relation to traditional semiconductor production (anyway, I assume this idea is broadly for learning/experimentation/the lols, rather than some earnest aspiration for using metal-bearing printer filaments to produce active components).
- mycall 2y ago
  What about the use of power transistors that don't too well as silicon crystals afaik.

westurner 2y ago

From https://news.ycombinator.com/item?id=40759133 https://news.ycombinator.com/item?id=40759133 : > In addition to nanolithography and nanoassembly, there is 3d printing with graphene. And conductive aerogels, and carbon nanotube production at scale From https://news.ycombinator.com/item?id=41210021 https://news.ycombinator.com/item?id=41210021 : > There's already conductive graphene 3d printing filament (and far less conductive graphene). Looks like 0.8ohm*cm may be the least resistive graphene filament available: https://www.google.com/search?q=graphene+3d+printer+filament+ohms https://www.google.com/search?q=graphene+3d+printer+filament... > Are there yet CNT or Twisted SWCNT Twisted Single-Walled Carbon Nanotube substitutes for copper wiring? Aren't there carbon nanotube superconducting cables? Instead of copper, there are plastic waveguides