@humy
The device can't turn off.
So if you replace precious metals with graphene in a cellphone it can't turn off.
No band gap.
https://www.technologyreview.com/2013/08/20/15430/how-to-save-the-troubled-graphene-transistor
@humy saidMy mistake.
That isn't what is meant by "free energy" in this OP context but rather its meant as 'free' in the thermodynamic sense as its a way of generating electrical energy from background thermal energy at thermal equilibrium and thus without a temperature difference. They don't mean 'free' in the monetary sense. You really must read the OP link to see what this is about. Read my third ...[text shortened]... n THAT sense. There would always be manufacturing and distribution costs and nobody would deny this.
@cheesemaster saidGraphene can be given a band gap simply by doping it with some non-carbon atoms. For example;
@humy
The device can't turn off.
So if you replace precious metals with graphene in a cellphone it can't turn off.
No band gap.
https://www.technologyreview.com/2013/08/20/15430/how-to-save-the-troubled-graphene-transistor
https://pubs.rsc.org/en/content/articlelanding/2012/nr/c2nr11728b#!divAbstract
"...Band gap opening of graphene by doping small boron nitride domains ..."
In this way a working graphene transistor can be and already has been made (at least in the lab) and thus it can be made to "turn off", as you put it. Example;
https://www.chemistryworld.com/news/inorganic-dopants-behind-graphene-transistor-progress/3010234.article
"...
Inorganic dopants behind n-type graphene transistor progress
...
Scientists in India have made graphene field-effect transistors that work for over 10 months
..."
Sometimes the doping elements used (at least in the lab) are common chemical elements, such as phosphorus, nitrogen, etc, as opposed to rare expensive chemical elements, thus showing potentual ways of avoiding the unwelcome issue of using rare expensive chemical elements.
That said, I don't believe that the ultimate far-future transistors would necessarily be graphene-based. But graphene has several significant potential uses other than for transistors, such as for ballistic conductors (see https://en.wikipedia.org/wiki/Ballistic_conduction ) and also certain types of sensors etc, and I believe there will almost inevitably be at least some important far-future application for it.
@humy
Graphene transistors won't become commercial until making graphene becomes cheaper.
But the 'free energy' from graphene, will never generate enough power to power a cell phone which needs real watts to run.
If you made enough graphene to power a cell phone it would maybe fit in the back of a pickup🙂
@sonhouse saidFor this device to be useful and go commercial, I think at least 2 things must happen first;
@humy
Graphene transistors won't become commercial until making graphene becomes cheaper.
But the 'free energy' from graphene, will never generate enough power to power a cell phone which needs real watts to run.
If you made enough graphene to power a cell phone it would maybe fit in the back of a pickup🙂
1, A cheap way must be found of manufacturing huge amounts of flawless graphene sheets all exactly the right shape and to the very last atom.
(and I am confident that one day that will be done via using artificial enzymes designed by AI. But I will need to start another thread to elaborate my theory of exactly how and why that would be done because that's quite complicated)
2, The power density of the device must be made sufficiently high and at least something vaguely like one-tenth of that of the older low-power density types of batteries (but, of course, the higher the better and if made as high as lithium batteries then that would be excellent!)
@humy
According to the article...
When you apply a band gap to graphene so it can be used in electronics you would need to add chemicals or elements and then it is no longer "graphene"
So... As of right now it is cheaper and better to use what we have.
Maybe in a few decades something will happen but why do scientists obsess over future applications that will be around long after they are dead?
I never understood that.
@cheesemaster saidI don't know where you read that but that often is wrong as we often talk about "doped graphene" and, in addition, even naturally occurring graphene isn't (even though we often inaccurately say it is) strictly pure carbon as it always has some non-carbon impurities; but perhaps that's being just a bit pedantic.
@humy
add chemicals or elements and then it is no longer "graphene"
Of course, if you change it so that most of the atoms are no longer carbon then it certainly wouldn't be considered to be still graphene.
But if you replace only an arbitrarily low proportion of the carbon atoms, say, less than 5% of them, with some other element then it would generally be considered to be still graphene providing most of the remaining molecular structure is kept as a graphene molecular structure.
I just watched these two short (~5 min and ~2 min long) videos about this and at one point each actually seriously implies this device could be used as a practical and widely used low-power battery replacement!
But what I (and surely many others) really want to know is what is the theoretical maximum power density of this kind of device and can its power density ever be high enough to really ever possibly serve as the main way we can realistically generate most of our electricity in the real world? -I really hope the answer is yes and especially the second video seems to imply the answer is yes but I do seriously wonder if that's just premature over-optimism.
I had an idea what shall we call i.e. name the mentioned OP kind of device or, more generally, any other devise that can generate electrical energy from thermal energy without a temperature difference and not necessarily via using graphene;
Simply call it a "cool generator" because this device is an electric generator and the effect of drawing current from this generator is a cooling effect on this device as the thermal energy within it gets converted to electrical energy.
Just a thought;
With this 'cool generator' (what I have decided to call the mentioned OP device), unlike with fossil fuels or batteries etc, it would be meaningless to talk about its 'energy density' or 'specific energy', because both of those things are either undefined for it or are potentially infinite!
Instead, we can only talk about its 'power density', and only compare its power density, not its energy density, with fossil fuels and batteries etc
@humy saidNO! Changed my mind because I have just thought of a better name for this device;
I had an idea what shall we call i.e. name the mentioned OP kind of device or, more generally, any other devise that can generate electrical energy from thermal energy without a temperature difference and not necessarily via using graphene;
Simply call it a "cool generator" because this device is an electric generator and the effect of drawing current from this ge ...[text shortened]... ol[/b]ing effect on this device as the thermal energy within it gets converted to electrical energy.
We can name this device after one of its other unique physical effects, more specifically, the effect it has of decreasing thermodynamic entropy in a closed system as you draw current from it.
So call this device a 'ted device', or just 'ted' for short, where the three letters of the word 'ted' (simply pronounced 'ted' ) comes from the abbreviation of the three words Thermodynamic Entropy Decreaser, or, alternatively, if you prefer, either Thermodynamic Entropy Dilator or Thermodynamic Entropy Diminisher, because this is literally what this device is and any of those choices abbreviates to the letters 'TED' as required.
Then we can also talk about 'ted power', meaning electric power coming from these ted devices as opposed to 'solar power' or 'wind power' etc.