5 ms·

Can someone ELI5 why graphene, defined as "a sheet of carbon just one atomic layer thick", can be sold as a "chip"? Of what use would be a one-atom-thick "chip"

by fernly 8y ago

Can someone ELI5 why graphene, defined as "a sheet of carbon just one atomic layer thick", can be sold as a "chip"? Of what use would be a one-atom-thick "chip"? Also, "graphene-based chips could deliver speeds more than ten times faster than silicon chips" -- wut? The basic reason (I thought) silicon could be used to make integrated circuits is that it is mostly NON-conductive, but can be made conductive in part, so as to form e.g. capacitances, insulated conductors, diodes, etc. But in my ignorance I thought the one thing that graphene has to be, is conductive, completely conductive in all directions. So how can you make the various parts of a circuit in a material that is one big short circuit?

sandworm101 8y ago
I think they means the graphine as the conducting wires. Someone probably told them wires/bands 1-atom thick connecting parts = smaller chips = faster chips. Id also be interested in what happens in terms of heat. Such small structures conducting electricity Would graphine parts on a chip get hot enough to combust?
- swish_bob 8y ago
  Graphene is a better heat conductor as well, so heat ought not to be as big a concern.
T-A 8y ago
https://futurism.com/graphene-computers-work-1000-times-faster-use-far-less-power https://futurism.com/graphene-computers-work-1000-times-fast...
- fernly 8y ago
  Thank you, but the text of that article is, um, science-challenged, for example, > At room temperature, graphene is also capable of conducting electricity 250 times better than silicon, a rate faster than any other known substance. Conducting "better", by which I think they are referring to resistance or conductance, has no relation to "speed" of current flow. So that sentence is noise. And I don't think it's possible for current to move 250 times faster even in a superconductor. Current in silicon is already a good fraction of the speed of light.[0] Their description of a graphene transistor is not much better, > They then applied a magnetic field to the graphene ribbon, which made them realize they could control the resistance of the flowing current through the ribbon. This confusing sentence seems to be trying to describe a magnetically-controlled switch, with an applied field throttling the current flow in a graphene conductor. Hall effect? OK, now you made me try to find something better. The Wikipedia article on Possible Uses of Graphene[1] does talk about transistors[2] but primarily as FETs[3] and says nothing about magnetic control. A magnetic field does produce a Hall effect[4] but this is not the same as a transistor. As for switching speed, [2] says "In 2013 researchers created transistors printed on flexible plastic that operate at 25 gigahertz" which is fast but not faster than silicon. 0. https://en.wikipedia.org/wiki/Speed_of_electricity https://en.wikipedia.org/wiki/Speed_of_electricity 1. https://en.wikipedia.org/wiki/Potential_applications_of_graphene https://en.wikipedia.org/wiki/Potential_applications_of_grap... 2. https://en.wikipedia.org/wiki/Potential_applications_of_graphene#Transistors https://en.wikipedia.org/wiki/Potential_applications_of_grap... 3. https://en.wikipedia.org/wiki/Field-effect_transistor https://en.wikipedia.org/wiki/Field-effect_transistor 4. https://en.wikipedia.org/wiki/Potential_applications_of_graphene#Hall_effect_sensors https://en.wikipedia.org/wiki/Potential_applications_of_grap...
  - techsin101 8y ago
    Less resistance less heat not compact transistors
  - pjc50 8y ago
    "Speed" in integrated circuits is mostly determined by RC delay - the need to charge the gate capacitance of the destination transistor, through the resistance of the interconnnect (metal, usually aluminium) and the gate on-resistance of the driving transistor. So lower interconnect resistance would make a real speed difference.
  - swish_bob 8y ago
    Does the nature article that futurism piece was talking about make it clearer? https://www.nature.com/articles/ncomms15635 https://www.nature.com/articles/ncomms15635
  - T-A 8y ago
    It's obviously a popular text, but the second paragraph includes a link to the actual paper; you could have saved yourself some searching by simply clicking that: https://www.nature.com/articles/ncomms15635 https://www.nature.com/articles/ncomms15635 As for the "rate faster" sentence, you are misinterpreting it. It's referring to the amount of charge transferred per time unit, not speed of propagation. See https://en.wikipedia.org/wiki/Ohm%27s_law https://en.wikipedia.org/wiki/Ohm%27s_law Reduce R and I goes up.

by fernly 8y ago

sandworm101 8y ago

I think they means the graphine as the conducting wires. Someone probably told them wires/bands 1-atom thick connecting parts = smaller chips = faster chips. Id also be interested in what happens in terms of heat. Such small structures conducting electricity Would graphine parts on a chip get hot enough to combust?

swish_bob 8y ago
Graphene is a better heat conductor as well, so heat ought not to be as big a concern.

T-A 8y ago

https://futurism.com/graphene-computers-work-1000-times-faster-use-far-less-power https://futurism.com/graphene-computers-work-1000-times-fast...

fernly 8y ago
Thank you, but the text of that article is, um, science-challenged, for example, > At room temperature, graphene is also capable of conducting electricity 250 times better than silicon, a rate faster than any other known substance. Conducting "better", by which I think they are referring to resistance or conductance, has no relation to "speed" of current flow. So that sentence is noise. And I don't think it's possible for current to move 250 times faster even in a superconductor. Current in silicon is already a good fraction of the speed of light.[0] Their description of a graphene transistor is not much better, > They then applied a magnetic field to the graphene ribbon, which made them realize they could control the resistance of the flowing current through the ribbon. This confusing sentence seems to be trying to describe a magnetically-controlled switch, with an applied field throttling the current flow in a graphene conductor. Hall effect? OK, now you made me try to find something better. The Wikipedia article on Possible Uses of Graphene[1] does talk about transistors[2] but primarily as FETs[3] and says nothing about magnetic control. A magnetic field does produce a Hall effect[4] but this is not the same as a transistor. As for switching speed, [2] says "In 2013 researchers created transistors printed on flexible plastic that operate at 25 gigahertz" which is fast but not faster than silicon. 0. https://en.wikipedia.org/wiki/Speed_of_electricity https://en.wikipedia.org/wiki/Speed_of_electricity 1. https://en.wikipedia.org/wiki/Potential_applications_of_graphene https://en.wikipedia.org/wiki/Potential_applications_of_grap... 2. https://en.wikipedia.org/wiki/Potential_applications_of_graphene#Transistors https://en.wikipedia.org/wiki/Potential_applications_of_grap... 3. https://en.wikipedia.org/wiki/Field-effect_transistor https://en.wikipedia.org/wiki/Field-effect_transistor 4. https://en.wikipedia.org/wiki/Potential_applications_of_graphene#Hall_effect_sensors https://en.wikipedia.org/wiki/Potential_applications_of_grap...
- techsin101 8y ago
  Less resistance less heat not compact transistors
- pjc50 8y ago
  "Speed" in integrated circuits is mostly determined by RC delay - the need to charge the gate capacitance of the destination transistor, through the resistance of the interconnnect (metal, usually aluminium) and the gate on-resistance of the driving transistor. So lower interconnect resistance would make a real speed difference.
- swish_bob 8y ago
  Does the nature article that futurism piece was talking about make it clearer? https://www.nature.com/articles/ncomms15635 https://www.nature.com/articles/ncomms15635
- T-A 8y ago
  It's obviously a popular text, but the second paragraph includes a link to the actual paper; you could have saved yourself some searching by simply clicking that: https://www.nature.com/articles/ncomms15635 https://www.nature.com/articles/ncomms15635 As for the "rate faster" sentence, you are misinterpreting it. It's referring to the amount of charge transferred per time unit, not speed of propagation. See https://en.wikipedia.org/wiki/Ohm%27s_law https://en.wikipedia.org/wiki/Ohm%27s_law Reduce R and I goes up.