How tough can we make something, compared to sci-fi

[Omega-13]

An example, lets look at a few cyborgs and androids from popular science fiction shows or movies

Superbattle droids
Data
t-800
Robocop
Solo

there are more, but i'm sure you can come up with them aswell, basically my question,

With new material we are discovering, such as carbon nanotubes, rated at 200 Giga Pascals,
100 times stronger than steel, and only 1/6th the weight,

How tough can we make future robots compared to what we see in science fiction,
I mean, i'm just trying to wrap my head around something 100 times stronger than steel, actually the nasa webpage its 'atleast' 100 times stronger than steel,

[Darth Wong]

With new material we are discovering, such as carbon nanotubes, rated at 200 Giga Pascals, 100 times stronger than steel, and only 1/6th the weight,

Please provide a link to the stress-strain curve of these nanotubes. The only cite I could find of empirical testing was here, and it says 30 GPa, not 200 GPa. And at 5% elongation, which indicates fairly brittle behaviour.

Besides, how are you going to make robots out of micro-threads which have high tensile strength but no compressive strength whatsoever? Wrap layers, like existing carbon fibre? Sorry, but AP bullets will pass through that, as will knives.

How tough can we make future robots compared to what we see in science fiction, I mean, i'm just trying to wrap my head around something 100 times stronger than steel, actually the nasa webpage its 'at least' 100 times stronger than steel,

Keep in mind that people love to make things sound more impressive than they really are. We've been hearing about all sorts of carbon fibres and composites that are "stronger and lighter than steel" for decades; we still use steel. Materials science is much more complex than a single unqualified figure.

[Omega-13]

http://focus.aps.org/story/v5/st26

while this site isn't stating 200, GPa, i'm still looking for a good site for that, i saw it, but it was just mentioned

this site is pretty good though, have a look

[SWPIGWANG]

200GPA!?

*is annoyed that have to build bridge using 6Mpa level material....

[Darth Wong]

200GPA!?

*is annoyed that have to build bridge using 6Mpa level material....

*Reminds SWPIGWANG that it would be pretty hard to build a bridge with flexible fibres*

[Sea Skimmer]

200GPA!?

*is annoyed that have to build bridge using 6Mpa level material....

*Reminds SWPIGWANG that it would be pretty hard to build a bridge with flexible fibres*

A causeway woundn't be too hard though.

[gravity]

Apparently there already exist carbon fibres strong enough to build a space elevator, that would be pretty cool/useful.

[Stormbringer]

Apparently there already exist carbon fibres strong enough to build a space elevator, that would be pretty cool/useful.

There aren't. We're getting closer to the strengtrh needed, now we need to work on the quantity.

[Darth Wong]

Something we have to keep in mind is that the 200 GPa figure is purely theoretical. It has not been observed in practice (carbon monotubes in testing have failed at stresses ranging from 10 to 50 GPa; an extremely wide range which averages to about 30 GPa).

[Moonstone Spider]

Although I have no certain knowledge of this matter, I understand efforts to make synthetic spider threads are yielding some very strong flexible fibers.

However I suspect that all these miracle substances will be insanely expensive even if they do deliver on their promises, and your power-android will cost millions of dollars, for which a thousand normal soldiers could be built to kick it's keister in any serious fight.

[Colonel Olrik]

Keep in mind that people love to make things sound more impressive than they really are. We've been hearing about all sorts of carbon fibres and composites that are "stronger and lighter than steel" for decades; we still use steel. Materials science is much more complex than a single unqualified figure.

The mmain reason we use steel, I believe, is not that it is better, but that it is much more cost effective. Steel is very cheap, and suitable for most applications, so there is really no pressure to change.

Aluminum leagues, for example, are at the very least twice as costly as steel, and just don't have enough advantages in most applications.

Composite materials can, and are, be made stronger an lighter than normal steel. Thermoplastic has the flexibility of carbon and the resistence is given by mixing other elements. It just costs a lot more (more or less 10x more).

In mountain bikes, for example, steel has definitely been put aside (except in the lowest end bikes) for titanium, carbon, thermoplastic and aluminum leagues, with gain of strength and flexibility. Unfortunetely, my wallet got lost weight after buying mine.

[gravity]

Apparently there already exist carbon fibres strong enough to build a space elevator, that would be pretty cool/useful.

There aren't. We're getting closer to the strengtrh needed, now we need to work on the quantity.

Actually, according to NASA there are already fibres strong enough, and long enough (more than 4 cm), but they haven't figured out how to mass-produce them yet.