
Self-Healing Transistors for Chip-Scale Starships - blackwingbear1
http://spectrum.ieee.org/tech-talk/semiconductors/devices/selfhealing-transistors-for-chipscale-starships
======
scrumper
"With this “nanoship”, travel time to Earth’s nearest neighboring stars is
reduced to just 20 years, as the chip can travel at one-fifth of the speed of
light. ... But 20 years is a huge step up from the expected deep space travel
time we’re currently capable of. For instance, it would take more than 100
years to get to Alpha Centauri."

So currently we are able to reach Alpha Centauri in 100 years? And now this
magical chip can travel at 20% the speed of light? I'm either a horrible
reader or this article left some _really_ important details out!

~~~
Tade0
I think the author is referring to the usage of light sails coupled with
lasers to achieve this.

Obviously this design scales horribly, so you'll want your spacecraft to be as
light as possible.

As for the numbers they look as if he, pardon my french, pulled them out of
his ass.

------
jayajay
It seems complicated to let our materials get damaged and then try to fix them
on the fly. The earth protects itself from charged particles via a gigantic
dipole field. Could the same be done with nano-electronics?

Boards could be designed to generate magnetic fields via embedded current
loops. Instead of having a wire connect two components in a straight line
(shortest path approach), it could be done in a way that meanders around,
intentionally creating large curls. Since we're talking about scales of 1e-9m,
these fields would probably be pretty strong.

Now, I don't know too much about superconductors, but vacuum tends to be
pretty fucking cold (2K -- surely, lower than the critical temperature for
many superconducting materials). It might even be possible to create a
Meissner cage around the important components, in a way that protects our
components from self-harm, while still protecting them from external charged
particles.

Has this theory been tested? After all, it works for the Earth. I am afraid
doing that might also be detrimental to our electronic components (unless we
can somehow create a diamagnetic cage to selectively protect our components).

~~~
HCIdivision17
I think the main problem is of scale. The Earth's field isn't too strong, but
it is _huge_ in expanse. That's a lot of distance to deflect and decelerate.
Going from a million meter diameter to a billionth likely requires a honking
big*large field strength to deflect as hard.

Also while space has a very low temperature, it's an impressively terrible
conductor of heat and thus a garbage cold sink. To keep things cool you either
have to wait for the heat to radiate out or to off gas your coolant. You could
generate radiative fins for the chips, but I don't know how effective that is
in space; I would assume they would be so gossamer it would be hard to keep
them from corroding in the solar wind.

But maybe that's just an engineering problem.

~~~
jayajay
[https://www.google.ch/patents/US7157290](https://www.google.ch/patents/US7157290)

It looks like these people have patented a classical/macroscopic version of a
similar idea. They talk about using a completely separate solenoid to deflect
incoming ions. Unfortunately they don't do any calculations (none that I could
find) to see if it would even work?

What I'm suggesting is a bit different - a change to the transistor and
microscopic wire structure so that components would be protected from external
charges via self produced magnetic fields.

So, it would look like a bunch of little spins on a grid, some activated, some
not activated, like 2D-Ising pretty much, but not random -- the directions are
defined by the logic running on the board.

I think you are right, though. These B fields act over too short a distance in
order to allow a relativistic particle to radiate an appreciable amount of
energy before doing damage.

~~~
HCIdivision17
There's definitely an effect, but from my intuition I'd guess it'd have to be
fairly strong. But maybe if they're cheap enough to produce and easy enough to
mass up, you don't have to even be that effective.

Here's where my intuition is anchored, and you can figure if it's applicable
(because I worked in a very different field). In magnetron sputtering, you
ionize a gas as it passes through a strong magnetic field (harddrive magnet
strength). Once the molecule ionizes (since it's moving at sonic speeds in the
vacuum), it whips around and slams into some target, blasting molecules back
from the target like a shotgun to a pile of dirt. These sputtered
molecules/bits of material may be slightly charged, and when they hit the
substrate will carry that charge and deposit it onto the substrate. Over time
an insulating substrate (like glass) will charge up a bit, and this will begin
to repulse incomming splattered charged bits. It'd be called something like
'biasing' and slows down the deposition rate, since the incomming material may
slow too much to properly embed itself on the substrate. The magnets behind
the target also trap electrons (in what is often called a racetrack), which
helps amplifies ionizing the gases (since a strong field may not ionize the
incoming gas molecules, but plonking an extra electron onto it will).

It tends to be a game of small effects in big numbers. Any individual
interaction can vary wildly from one interaction to another, but over many
trillions of trillions of events it averages out like you'd expect scales
similar to Avagadro's number to. So if we could fabricate stupefying amouts of
these gizmos, you wouldn't need it to be completely effective; just enough
biasing or field strength to tilt the odds a bit in your favor and a lot of
the little chips could survive. And if you have enough, you win! Sure the
solor wind may clobber a few chips, but if you have billions enough of them,
perhaps enough survive to keep effective.

This is part of the approach to some MEMS gizmos, where you play the odds and
make huge numbers of the gizmos with a cheap fast process and filter out the
working ones. Ideally you'd be smart and just have a really good process, but
if your fabrication process is messy or too hard to control and the gizmo
valuable enough you can take the losses. (I mean, you don't do that - you
engineer good processes! But... well, that can be expensive. And sometimes
waste is cheaper.)

EDIT: I'm thinking of the spherical cow equivalent of a gizmo here, too. You
prolly wouldn't make billions of little computers and hork them at another
star system unless you could essentially replicate them chemically. But not
with a photolithographic process typical to chip designs. You can get
millions, not trillions of trillions. Have something that self-assembles in a
beaker and then perhaps it becomes an option. But that's sort of like hurling
a viral infection at another star system, and... well, kinda gunks the idea
too.

~~~
jayajay
Your example (sputtering charge onto insulator) is of a similar flavor (but
with E fields). The OP article seems like a monkey-patch way of "self-repair".
Should we also create a self-repairer for the self-repairer? Little arms
repairing other little arms repairing other little arms which are repairing a
Raspberry PI. It's a cute, steampunk-y image -- what I imagine Leonardo Da
Vinci would have jotted down in a book somewhere.

Alternatively, what you said: we could just send out a large number of
duplicated devices. This might be easier, but more expensive.

How are computers even designed? If a single part fails, the entire thing can
still function, more or less -- true or false? What about a brain? A body?
Organs? My hand would still work, even if I ripped off a significant chunk of
skin and flesh. It will even repair itself over time (the flavor of the OP
article). If I cut a biofilm or an earthworm in half, both halves will "work".

Now, I am not a computer scientist, computers obviously aren't like biofilms
-- but I am not familiar with the extent of this dissimilarity. For example,
if I randomly remove 2,000 transistors from a computer (simulating solar
wind), what is the probability that the computer will be rendered useless?

The second way I interpret what you say is that we actually redesign our
computers, inspired more by biology, to be able to still work even if some
computing elements or memory elements are flipped or destroyed. This is
probably way outside of my lifetime, though.

But we are already seeing this in the ML community, with things like dropout.
If I removed a random set of nodes from a deep learning network, the network
would still work fine, more or less...

Edit 2: So, if we had something like that glass with the charged layer (i.e.
maybe transistors which created a small magnetic dipole, so the entire device
was effectively a ferro magnet), some elements would cop-out and the system
would be rendered useless unless it was designed to be robust like an organ
losing some cells. But that sounds really hard. We want the transistor or
component to maintain some internal state, while being a magnetically shielded
box. Hmm... almost like a topological insulator with a doped body.

~~~
HCIdivision17
Robustness really depends on the computer these days, I think. Flash drives
already route around bad sectors, and most computer chips are capable of
gracefully degrading performance as sections fail (one of the ways chip yields
go up: over build the chip so failures can be routed and sold as a cheaper
variant).

To your first line, the micromachine-for-micromachines idea often reminds of
Feynman's talk "There's Plenty of Room at the Bottom" [0], which is great at
least in how long ago it was made. Turns out it's a really hard problem. There
have been some functional versions of the micro arm-onna-arm designs, but
they're just stupendously hard to control. I'd love to see some progress on
that front, though, because it really is cool when it works.

[0]
[http://www.pa.msu.edu/~yang/RFeynman_plentySpace.pdf](http://www.pa.msu.edu/~yang/RFeynman_plentySpace.pdf)

~~~
jayajay
Was this the paper that made Feynman the father of "nanotechnology"? This
paper's spirit reminds me of Leonardo Da Vinci's futuristic drawings.
Incredible that this was written in 1959. I keep thinking to myself when
reading this -- only if Feynman was around to see AFM and STM. I think those
were created just before he died. I wish he had more time to play around with
those, he probably would have loved them. Feynman had truly a deep
imagination.

I intended the arm-on-an-arm expression to be conceptual imagery, more so in-
line with your link, less with OP article. What do you mean by "some
functional versions" of this? Please link!

~~~
HCIdivision17
I've been out of the field for a while, so I don't really know the state of
the art anymore. But I had the pleasure of visiting what was then called the
Texas Microfactory. It's basically a sort of microvoxel printer, capable of
moving components around on a small stage.

Here's a link to a paper on the machine, I think: [https://hal.archives-
ouvertes.fr/hal-00417722/document](https://hal.archives-
ouvertes.fr/hal-00417722/document)

And a thesis on the gizmo:
[http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.599...](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.599.6325&rep=rep1&type=pdf)

I haven't read it, but it does have some cool pictures around page 40.

As you might imagine, control is the hard part. Damn thing was wobbly like all
get out, to the point that it building anything at all was the impressive
part. And it did - it wasn't practical for mass production, but it certainly
could do cool things.

------
woofyman
What would the chip do once it got to the star? Seems pretty useless without a
power source, transmitter and an antenna.

~~~
planteen
Not to mention it wouldn't be able to point at the star without some
actuators.

~~~
simonh
The starship concept involves solar powered chips launched initially into
orbit, then boosted to 0.2C by a ground based laser. They're cheap and tiny
and launched in the thousands over the entire period the first probes are in
flight, so you have a continuous chain of probes. The return signal is passed
back along the chain to Earth. The probes steer using thermal effects and
solar wind. Many probes work together to form a synthetic aperture array.

~~~
woofyman
Since its 4.47 x 9.5 x 10 to the 15th power meters to alpha century, it
doesn't seem feasible to form a communication chain of such tiny devices. How
are they powered in deep space?

~~~
thatcherc
Presumably using light from the laser. I forget the exact numbers, but the
proposed laser is on the order of hundreds of gigawatts. Even at 4 ly away,
there should still be appreciable illumination from Earth.

~~~
jsjohnst
Hundreds of gigawatts!? To my knowledge, there's never been a laser remotely
that powerful that can emit for any constant duration.

The highest power laser [0] in the world currently is 2 petawatts and it can
only fire for _one trillionth of a second_. Per the same article (not sure on
validity) the entire world electricity usage is somewhere around 2 terawatts,
so something producing a continuous 0.1+ terawatt beam would be an incredible
cost that's simply impractical proposition any time soon.

[0]
[http://www.dailymail.co.uk/sciencetech/article-3179045/The-D...](http://www.dailymail.co.uk/sciencetech/article-3179045/The-
Death-Star-weapon-Japan-just-fired-world-s-powerful-laser.html)

~~~
unwind
I'm just jumping in here, but while we're in sci-fi land let me point out that
this is usually not done from the Earth's surface (pushing 100 GW through the
atmosphere is sub-optimal) but instead in near-Earth orbit, or from the Moon's
surface, or something.

So, the power output of the Earth is not 100% relevant, it wouldn't be a load
on the planetary grid.

~~~
jsjohnst
Which makes it an even crazier proposition! The existing ultra high power
lasers are so big in size that they'd currently be impractical bordering on
implausible in space. To power it, we'd have to take every nuclear power plant
on earth (plus another 2-3x more) and put them up in space. Seems likely, no?
:P

------
astebbin
Does the technology exist which could accelerate a nanoship to "one-fifth the
speed of light", or perhaps more importantly, course-correct and slow it down
as it nears its destination?

~~~
Thorondor
Not yet, but Breakthrough Starshot is working on it.
[https://en.wikipedia.org/wiki/Breakthrough_Starshot](https://en.wikipedia.org/wiki/Breakthrough_Starshot)

The numbers they are putting out are probably more than a little on the
optimistic side, but the project is definitely a serious attempt and I'd love
to see it succeed.

------
Aaron1011
I didn't get a clear sense of what exactly 'chip-scale' would mean from
reading the article - presumably on the order of centimeters?

------
corndoge
Moon is a hell of a last name for a NASA scientist.

------
lintiness
tech could do a lot of things, but this isn't one of them.

------
mxvzr
Poorly written title/article (if you can call it that). At least it contains a
link to ieee.org with more content [1]. See also arstechnica [2][3] for some
earlier coverage.

[1] [http://spectrum.ieee.org/tech-
talk/semiconductors/devices/se...](http://spectrum.ieee.org/tech-
talk/semiconductors/devices/selfhealing-transistors-for-chipscale-starships)

[2] [http://arstechnica.com/science/2016/04/breakthrough-
starshot...](http://arstechnica.com/science/2016/04/breakthrough-starshot-
announces-plans-to-send-ship-to-alpha-centauri/)

[3] [http://arstechnica.com/science/2016/08/could-breakthrough-
st...](http://arstechnica.com/science/2016/08/could-breakthrough-starshots-
ships-survive-the-trip/)

~~~
sctb
Thanks, we've updated the link from [https://futurism.com/this-self-healing-
tech-could-let-us-rea...](https://futurism.com/this-self-healing-tech-could-
let-us-reach-the-closest-alien-stars-in-just-20-years/).

~~~
zodPod
Are you saying you work at futurism? Can you address the annoying newsletter
nag that happens when you load the page the first time? It may be mostly
"inconsequential" but in an internet where we are constantly bombarded with
annoying forms interrupting our reading, bothering us to give up our
information, can't you try to be better than that?

~~~
sctb
Ah, I see the ambiguity here. I work on Hacker News, so I updated the link of
this submission to the ieee.org article, which was linked to by the
futurism.com one. (Sorry to disappoint about the nags)

~~~
dmichulke
I'm sure spectrum.ieee.org will be very happy to see who exactly was
responsible for their site being down ;)

The other links still work though...

