Processors have come a really long way over the past few decades, but one thing that's remained constant is the fact that they're based on silicon wafers.
But it turns out we don't have to use silicon substrates.
In fact, if we print transistors on another type of material, we could get processors that are not only cheaper, but bendable.
That's right. While everyone is talking about foldable phone screens, scientists have been working on a flexible ARM-based processor
printed on plastic. But how the heck do you put transistors on plastic and why would we want a flexible CPU anyway?
So it turns out that we've actually been putting transistors onto materials other than silicon for a long time now.
Specifically, I'm talking about oxide thin film transistors, better known as TFTs.
These have been used for quite a while in run-of-the-mill LCD screens.
The idea is that instead of silicon, the transistors are printed onto some kind of non-conducting substrate, such as glass.
But even though we've been using this tech for displays for a long time, full-fledged CPUs are a much more complicated ballgame,
kind of like when you get a double reverse triple-out-of-bounder in the 8th inning.
And the bendable CPU we're talking about today is notable because not only is it, well, a full-fledged CPU,
but it uses an existing architecture that's already been put into tons of devices, the ARM Cortex M0.
The new chip is essentially an M0 core, plus a small amount of memory on a plastic substrate, printed using photolithography,
meaning the printing process is similar to how conventional CPUs are made, which you can learn lots more about up in this video.
The transistors themselves can be made from indium-gallium zinc oxide, better known as
IGSO, again commonly used in TFT displays at a low cost.
Of course, since we're talking about cheap production methods, you might think that the plastic ARM, as it's called, isn't very computationally powerful, and...
Well, you'd be right. It runs at only 29 kilohertz and is built on an 800 nanometer process,
which is the same process the original Pentium's from 1993 used. Great year.
And the thing isn't even very power efficient. Despite the fact it uses 21 milliwatts of power, which seems low,
it turns out that 99% of that is lost to waste heat.
So yeah, it's slow and inefficient.
So what's the point? So, remember how we said the Cortex M0 is in a huge number of embedded devices already?
Putting the M0 on flexible plastic means a chip that's complex enough to handle more advanced functions
could go into many more products, especially in cases where silicon is too expensive or too brittle.
Even though the plastic ARM's implementation of the M0 is quite slow, as we said,
it should still be around 12 times as powerful as previous integrated circuits based on plastic.
Plastic ARM would have enough computational muscle to be connected to environmental sensors and alert users to real-time conditions.
Think about a plastic ARM chip inside food packaging that could tell if the food inside was spoiling instead of going by an expiration date.
Or how about a bandage that could keep an eye on how well your cuts are healing?
It's like a little tiny doctor on your finger. Although we do already have microchips that can accomplish some tasks that plastic ARM is envisioned for,
plastic ARM could enable them to be deployed in many more environments for much less money.
But I wouldn't expect to see it in the immediate future, as the plastic ARM prototype that was just developed can only execute a few hard-coded programs.
And scientists still need to make the chip more power efficient.
However, as time goes on, ARM believes we could see chips like these in more than a trillion objects over the course of 10 years.
Hopefully, some of them will end up in lottery tickets, so I can be disappointed as soon as the drawing happens.