
Ultralow power transistors that could function for years without a battery - taylorbuley
http://www.cam.ac.uk/research/news/engineers-design-ultralow-power-transistors-that-could-function-for-years-without-a-battery
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pjc50
It's rather badly explained, but it seems they've developed the _Schottky
transistor_ , using a TFT manufacturing process. Conventionally TFTs are slow
and leaky compared to a regular CMOS FET in silicon. It sounds like they've
greatly improved leakage, although I can't figure out where they say this in
the paper. This makes printable low-power circuits more plausible.

~~~
acqq
It is a "Schottky-barrier indium-gallium-zinc-oxide thin-film transistor
operating in the deep subthreshold regime." According to the original article
in Science Mag. the currents involved are significantly lower then of the
other possible technologies. It's not only that the OFF current is apparently
an order of magnitude lower (as a property of the use of that material, IGZO)
it's that the transistor does the useful work in the "almost off" state (as
they operate it in that regime). The low currents typically mean also "slow"
but for the applications intended it could be exactly what's enough, and the
advantages huge.

I don't see that they give any exact estimate of some real life application,
it can be that the practical uses technologically introduce some limitations
that aren't discussed. At least it looks promising.

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jhallenworld
Subthreshold logic is already in use.. check out Ambiq's Apollo ARM MCU.

[http://ambiqmicro.com/low-power-microcontroller](http://ambiqmicro.com/low-
power-microcontroller)

~~~
acqq
Thanks, here they describe the idea and the problems they faced:

[http://ambiqmicro.com/spot-platform](http://ambiqmicro.com/spot-platform)

"Operation at such low voltages is problematic due to susceptibility to noise,
high sensitivity to temperature, and variability due to process drift. In
developing the SPOTTM platform, Ambiq Micro has addressed all of these
challenges by redesigning every analog and digital circuit in the chip to
adapt for the temperature, voltage, and manufacturing variations that are
problematic at these voltage levels."

~~~
jhallenworld
Yeah, they are using the transistors near their highest gain point. It's
impressive that they got this to work- If you try this with through-hole
transistors, you will definitely be picking up your local AM station.

~~~
acqq
Do you by any chance know more details? I'd love to read about it.

~~~
jhallenworld
Well here is their paper:

[https://www.fujitsu.com/uk/Images/Ambiq_whitepaper.pdf](https://www.fujitsu.com/uk/Images/Ambiq_whitepaper.pdf)

Also always fun to look at their patents, but who knows which ideas are really
used in the chip:

[https://www.google.com/patents/US7009265?dq=ambiq&hl=en&sa=X...](https://www.google.com/patents/US7009265?dq=ambiq&hl=en&sa=X&ved=0ahUKEwiK_eOwm_fPAhXq5IMKHanxBR0Q6AEISTAG)

This thesis seems to have a good overview:

[http://www.eng.auburn.edu/~agrawvd/THESIS/KIM_S/S.Kim_Honors...](http://www.eng.auburn.edu/~agrawvd/THESIS/KIM_S/S.Kim_HonorsThesis_FINAL.pdf)

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aperrien
Could this type of transistor be used in stacked silicon chips? [1] It would
seem that such a low power transistor would produce much less heat, solving
one of the largest problems with the technology.

[1][https://en.wikipedia.org/wiki/Three-
dimensional_integrated_c...](https://en.wikipedia.org/wiki/Three-
dimensional_integrated_circuit)

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powera
Is this an ultra-low-current battery, or an energy generation technique?

~~~
m4x
It is neither. As the summary at the top of the article says, it is a
transistor that draws very little power.

~~~
visarga
And could be used with antennas that harvest electrical energy from the
background EM radiation. It could lead to battery-less sensors with long life.

~~~
leonix
Humanity on its road to invent Pham Nuwen's localizers from
[https://en.wikipedia.org/wiki/A_Deepness_in_the_Sky#Localize...](https://en.wikipedia.org/wiki/A_Deepness_in_the_Sky#Localizers)
:)

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kens
Better link: [http://www.cam.ac.uk/research/news/engineers-design-
ultralow...](http://www.cam.ac.uk/research/news/engineers-design-ultralow-
power-transistors-that-could-function-for-years-without-a-battery)

Paper abstract:
[http://science.sciencemag.org/content/354/6310/302](http://science.sciencemag.org/content/354/6310/302)

~~~
gerbal
Scihub link: [http://science.sciencemag.org.sci-
hub.cc/content/354/6310/30...](http://science.sciencemag.org.sci-
hub.cc/content/354/6310/302)

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JumpCrisscross
How credible is Futurism.com as a source? Futurism, LLC, a Delaware limited
liability company, was formed less than a year and a half ago [1]. In my
experience, their content tends to be breathlessly hyperbolic.

[1] _State of Delaware Department of State: Division of Corporations_

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russdill
It's impossible to read much into articles that are so incredibly buzz word
inundated. It sounds like a transistor with ultra low leakage power which is
becoming an increasing problem. You'd still have dynamic power consumption.

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Dylan16807
There's something about running entirely on leakage power, never powering on
into the normal region? I can't figure out what they're talking about with
scavenging power at all; if it could scavenge why would it only last 'months
or years'.

~~~
russdill
Scavenge is just used as a buzzword. Rather than having a battery, the IoT
device could be low enough power to use just piezo capture, EM capture, etc.

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gridspy
Bad title. Correct title "Low power transistor could massively extend battery
life"

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loop-programmer
Sounds like vaporware. These sorts of innovations rarely seem to be robust
enough to commercialize.

