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I wonder if someone has figured out how to use inkjet or screen printing to make a simple wifi/bluetooth transmitter or an NFC tag. So far I've only seen the a

I wonder if someone has figured out how to use inkjet or screen printing to make a simple wifi/bluetooth transmitter or an NFC tag. So far I've only seen the antennas printable but not the transistor logic.

parsecs 5y ago
I don't think inkjet printers have anywhere near enough resolution to get WiFi/BT or even NFC tags - those things are incredibly complicated. I expect it would also take a whole bunch of engineering to get the printed ink perform well at such high frequencies
- nl 5y ago
  Thus article talks about screenprinting RFID (=NFC) tags. I'd be surprised if an inkjet can't get higher resolution than screenprinting. Doesn't solve the transistor issue the OP was asking about though.
- alted 5y ago
  A WiFi/BT/NFC tag system has an antenna, and a radio circuit attached to the antenna. It's almost possible to inkjet print circuitry with transistors in research applications; see [1]. 20 micrometer resolution is relatively easy, so a WiFi/BT or NFC antenna (~millimeter scale) is very possible. I agree, the tricky bit is making (a) enough transistors to for the radio at (b) sufficiently high frequencies. As in [1], inkjet-printed transistor circuits have at most ~10 transistors as of yet (and NFC chips, with > 512 bit memory, need at least hundreds if not thousands). According to [2], inkjet printed organic transistors are in the range of MHz frequencies; NFC (~13 MHz) may be possible; WiFi (~2.2 GHz) may not be for a while yet. [1] https://news.ycombinator.com/item?id=24129506 https://news.ycombinator.com/item?id=24129506 [2] https://doi.org/10.1021/acsnano.6b06041 https://doi.org/10.1021/acsnano.6b06041
digikata 5y ago
It would be neat if you could print in some of the jellybean components - even just covering a range of resistors would be interesting.
- karmicthreat 5y ago
  You can already buy screen printable resistor inks.
- mastax 5y ago
  Printed carbon resistors used to be reasonably popular in the 80s and 90s [1]. The process fell out of fashion as components and assembly became cheaper. [1]: https://www.youtube.com/watch?v=Zao8upe4phs https://www.youtube.com/watch?v=Zao8upe4phs
- jimmyswimmy 5y ago
  I've done exactly this and the process remains available for e.g. Green tape /LTCC material. The accuracy of the components tends to be quite poor and capacitors are historically crap compared to discretes. But trimming is an option, and a well designed circuit can take advantage of the non idealities of the implementation. In that Era the state of the art was multiple layers of ceramic substrate. Modern techniques like Volterra have allow you to print the ink and insulation. No reason it can't also print resistors. You can have a ten layer single sided board, printed in your lab in an afternoon. My only issue with it is the relatively poor conductivity of the conductive ink. But that will be solved eventually.

parsecs 5y ago

I don't think inkjet printers have anywhere near enough resolution to get WiFi/BT or even NFC tags - those things are incredibly complicated. I expect it would also take a whole bunch of engineering to get the printed ink perform well at such high frequencies

nl 5y ago
Thus article talks about screenprinting RFID (=NFC) tags. I'd be surprised if an inkjet can't get higher resolution than screenprinting. Doesn't solve the transistor issue the OP was asking about though.
alted 5y ago
A WiFi/BT/NFC tag system has an antenna, and a radio circuit attached to the antenna. It's almost possible to inkjet print circuitry with transistors in research applications; see [1]. 20 micrometer resolution is relatively easy, so a WiFi/BT or NFC antenna (~millimeter scale) is very possible. I agree, the tricky bit is making (a) enough transistors to for the radio at (b) sufficiently high frequencies. As in [1], inkjet-printed transistor circuits have at most ~10 transistors as of yet (and NFC chips, with > 512 bit memory, need at least hundreds if not thousands). According to [2], inkjet printed organic transistors are in the range of MHz frequencies; NFC (~13 MHz) may be possible; WiFi (~2.2 GHz) may not be for a while yet. [1] https://news.ycombinator.com/item?id=24129506 https://news.ycombinator.com/item?id=24129506 [2] https://doi.org/10.1021/acsnano.6b06041 https://doi.org/10.1021/acsnano.6b06041

digikata 5y ago

It would be neat if you could print in some of the jellybean components - even just covering a range of resistors would be interesting.

karmicthreat 5y ago
You can already buy screen printable resistor inks.
mastax 5y ago
Printed carbon resistors used to be reasonably popular in the 80s and 90s [1]. The process fell out of fashion as components and assembly became cheaper. [1]: https://www.youtube.com/watch?v=Zao8upe4phs https://www.youtube.com/watch?v=Zao8upe4phs
jimmyswimmy 5y ago
I've done exactly this and the process remains available for e.g. Green tape /LTCC material. The accuracy of the components tends to be quite poor and capacitors are historically crap compared to discretes. But trimming is an option, and a well designed circuit can take advantage of the non idealities of the implementation. In that Era the state of the art was multiple layers of ceramic substrate. Modern techniques like Volterra have allow you to print the ink and insulation. No reason it can't also print resistors. You can have a ten layer single sided board, printed in your lab in an afternoon. My only issue with it is the relatively poor conductivity of the conductive ink. But that will be solved eventually.