What's the next big thing from the material engineers?

Kind of a poll but pretty technical so I’ll start it here in GQ.

Remember the 50’s & 60’s Sci Fi when alien spacecraft crash and us lowly humans find that they’re made from elements unknown?

Well, we pretty much know the periodic table right now - anything to be added up there on the end is likely to be sufficiently radioactive & too short of life to be useful.

So - the next big super-material will probably be a novel structure or alloy or something. Known elements being used in new ways.

So, what’s on the horizon? Nano-engineered carbon constructs (diamond everything)? The replacment of metals with ceramics?

Glassy metals are one candidate.

Carbon Nanotubes. They have a science-fiction-like tensile strength and very low mass, but we only know how to make short ones. Once we can grow them long, there’ll never be a good reason to use steel cable again (at least, not for certain uses, such as bridge cables).

That’s what they’re gonna make the Space Elevator out of.

There’s still a lot of potential in ceramics and composite materials, I think - look at products like ALON or Lumicera (two transparent ceramics) - I reckon there are still some big surprises to be had in that field.

Just read an article in the latest Scientific American about negative-refraction index materials. By creating a block of material made of zillions of tiny antennae of the right shape, you get a material that effectively has “impossible” optical qualities such as being able to resolve features smaller than the wavelength of light you’re using. The only current example operates in the microwave range, but they’re working on reducing the wavelengths to the infrared or optical range. It would allow virtually magical optics.

Carbon nanotube usage is certainly on the horizon (albeit a way off) for both structural and electronic uses. Because carbon may be made to exist in 0, 1, 2 and 3-dimensional form (I spent some time a couple of years ago trying to grow zero dimensional graphene islands. I didn’t do very well but I was never a very good engineer) and because single wall CNTs exist in both semiconducting and metallic forms they can be used to make pure carbon circuits. This will allow faster and smaller electronics to be built, possibly even useful quantum computers.

On a structural note, while CNTs are very nice the cost of making enough to provide useful reinforcement in a composite is prohibitive. in addition these generally only provide particulate type reinforcement, which is substantially poorer than fibre reinforcement. Bundles of fibres may be used but these are not as good as a theoretical very long CNT. In addition multiwall CNTs are seeing the most use in composits, however these have less strength than their single walled brethren. SWCNTs are by far the most expensive type of CNT so truly sci-fi type structural CNT materials may be a long way off.

I would expect a big increase in the usage of titanium alloys in the next 10-20 years as there are a number of groups around the world working on cheap methods of extracting titanium (it is after all the ninth most abundant metal in the Earth’s crust and it is only the expense of extraction that keeps its usage down). Maybe it’s not as space age as CNTs but it’s still pretty good.

I just graduated with a BS in materials engineering last month so I feel compelled to give my two cents. :slight_smile:

I do not foresee diamond becoming exceptionally more prevalent than it is. Diamond is the hardest known material and is very abrasive and temperature resistant, but also very brittle. The most common industrial applications for diamond is for cutting and grinding. For example, many industrial saw blades are diamond tipped. Diamond is too brittle and expensive to make “everything” (or hardly anything for that matter) out of it. However, I do think diamond prices will decrease in the coming years as scientists improve synthetic production of it using chemical vapor deposition (CVD).

Carbon nanotubes (CNTs) OTOH along with other nanofibers are on the horizon for use in many more applications than seen today. They have an incredibly low density, high tensile strength [IOW a high specific strength], and high resilience. There are already some composite materials reinforced by CNTs such as those used in high-end baseball bats and tennis rackets. Body panels in some GM cars are reinforced by olefin nanofibers.

CNTs also have unique electrical and chemical transport properties. I was a research assistant during my time as an undergraduate working on functionalized CNT-polystyrene membranes for possible future chemical separation applications in pharmaceutical and food processing industries. Here’s a link to an article related to my former research group.

I see that Fast ‘n’ Bulbous expanded on CNTs a bit.

Even the average run of the mill MWCNTs cost $750-$150 per pound these days so macro scale applications are nearly impossible. I do see greater use of CNTs in electronic and chemical transport applications though in the near future. CNTFETs may even replace MOSFETs (metal oxide semiconductor field effect transistors). The price of CNTs will continue to decrease each year but at a somewhat gradual rate.

Nah…like diamonds, ceramics are too brittle and expensive to replace metals in most applications. Usually, industrial ceramics are limited to applications involving high temperature and/or heavy abrasion but weak dynamic forces. For example, tungsten carbide is commonly found in drill bits. Also, there are cermet materials in use today which are a combination of ceramic and metal.

Composite materials were mentioned in previous posts. I certainly think these will continue to be more widely used and cheaply processed because of the desire to have stronger and lighter weight materials especially in fuel consuming vehicles. The next generation of airplanes including the Airbus A350 and Boeing 787 have structures that are mostly carbon fiber reinforced plastic composite materials. Fiber reinforced materials are still expensive to process: imagine trying to weave hair clippings through a wad of chewing gum keeping a consistent distance between strands of hair. That’s a challenge analogous to trying to manufacture composites.

Titanium is also difficult and expensive to process at least in its pure form, but not so much after it is alloyed with other metals.

Carbon nanotubes, once we can produce them practically, will be the biggest thing since knapped flint. But there are likely to be various other impressive materials before then. So it depends on your standard of “big”.

How about using diamond as aggregate in a concrete-type material (possibly with some synthetic matrix, rather than cement)? Would that be significantly better than ordinary sand/gravel?

High-temperature ceramics for gas turbines.

In order for a turbine to produce high efficiency power, one must somehow recycle the thermal energy otherwise lost in the exhaust. And ceramics can take combustion chamber temps that would melt any metal alloy.

Also, ceramics with room temperature superconductivity to eliminate wasted electrical power converted to heat.

I read about something similar (possibly related) - an array of tiny antennae that ‘receive’ light in the same way that a conventional antenna receives radio waves; it has been suggested that such a material could be used to make fantastically efficient solar cells.

Diamond as aggregates certainly could be used in as a reinforcement in a synthetic matrix that undergoes heavy compression and/or abrasion but I’ve never read about it or seen any failure analysis or performance data. It’s probably been done, but industrial grade diamond is expensive (though not as much as gemstone grade diamond) compared to other reinforcing materials. I have come across silica porous aggregates and other ceramic aggregates used in polymer matrices; I certainly think diamond could be used in their place as a better reinforcement if it were not for the high cost.

I keep reading about the potential for diamond-based semiconductors; apparently there have been encouraging results (although nothing commercial yet) in growing single-crystal diamond wafer and doping to make P and N type materials.

I am glad you metioned since I did not already (really, I could discuss materials science for days on end and still leave out certain topics). Carbon in single crystal diamond form has the same crystal structure as single crystal silicon so it’s no surprise that diamond could be doped with boron or phosphorous to make P or N type semiconductors respectively just like in silicon. One major advantage to diamond over silicon as a semiconductor is diamond retains its bandgap at much high temperatures. As I mentioned above, researchers are improving techniques for growing diamond synthetically through vapor deposition and possibly other processes of which I’m not yet aware.

Again, it’s going to be a cost effectiveness issue of when diamond becomes suitable for use as a commercial semicondor. Single crystal silicon cylinders are typically grown from a seed crystal in molten Si using a process called the Czochralski method. These cylinders are then sliced into thin wafers which then undergo a multitude of processes before becoming intergrate circuit chips. The ability to mass produce Si IC processors has absolutely revolutionized the modern world we know today. Developing a method to cost effectively mass produce single crystal diamond semiconductors likewise will be a huge challenge, but…hey, it may happen…we shall see. For now though, like you said Mangetout, diamond just has ‘potential’ for the mass market as a semiconductor.

I think a different approach may be required (if indeed it is possible at all) - silicon semiconductor manufacture consists of iterations of etching etc; if you’re going to the trouble of vapour depositing the diamond crystal, why not control this process to make the end product directly - maybe direct photostatic vapour lithography, or something equally simple(not).

Or it may turn out to be simply impossible, of course - maybe some quantum effect will make it actually impossible to reliably grow uniform single-crystal wafers, or something like that.

Both based on the idea of creating nano-antennae small enough that light waves look like electromagnetic current.

I keep hearing about gold nanoparticles. Depending on their geometry, they can be used in many different kinds of physical sensors based on the way plasmons propagate on their surfaces. Also, again depending on their geometry, they can act as catalysts for various reactions. They can also act as carriers for biological payloads.

Quantum dots, though not necessarily a ‘big thing’, helped with biological probes and better blue lasers. Quantum dot blue lasers will be included in Blu-Ray and HD-DVD drives.

FYI: It seems they have already overcome the wavelength limitation.

Carbon nanotubes seems to be big, but everyone else has already mentioned that. There is also research on using carbon fiber frames for autos instead of steel.

These sites usually have the most interesting news on cutting edge science, so materials research can be found there.