Vive La Nanotechnologie

A joint French-U.S. research team made nanotech history this month by constructing a first-ever molecular motor that sports an array of “rotor blades” that one can turn clockwise or counterclockwise. The team’s device, which measures an astonishingly small 2 nanometers in diameter, is understood to be a crucial next step toward eventually building complete "quantum machines" that operate according to quantum mechanics, rather than conventional mechanics, and thereby take machine capability to a whole new level. Theoretical quantum machines could power quanum computers, for instance, or sweep blood clots out of human arteries.

“These researchers’ work explores the mechanics and propulsion of molecule-motors, and it showcases the components of nano-robots of the future,” states a news release from France’s National Center for Scientific Research (CNRS), which additionally suggests that future nanorobots based on this device might be put to work mass-assembling more nanorobots. The research team included researchers from the CNRS, along with researchers from the University of Ohio.

In all, around 200 atoms constitute this nanomotor. The team started with a stationary “base” of a few atoms resting together atop a flat surface of gold. A single atom of ruthenium was placed on top of this base and would serve as a “ball bearing,” once the team placed on top of it, in turn, an additional moving “rotor” apparatus consisting of iron atoms that formed five outstretched “arms,” one of which was made shorter than the other, so as to make it easier for the researchers to track the motor’s overall motion.

Conjoining atoms of sulfur, serving as an “atomic glue,” pinned the complete motor to the gold surface. To move the rotor blades one way or the other, the researchers emitted electrons from a microscope.

The CNRS-Ohio nanomotor. The outstretched appendages are rotor blades. Credit: Nanocomputer.com

This nanomotor is a step above prior research endeavors, in that is both stand-alone and has multiple moving parts. Research labs all over the world have successfully forged molecules together into nanomotors prior to this one, but each of these finished products involved an individual molecule moving in various directions, not whole molecular structures.

For example, in September 2011, a Tufts University team debuted a first-ever “electric” nanomotor. Electricity powered it, which was noteworthy in that previous nanomotors were powered by much less-efficient chemical or light reactions.

But the whole motor was only one butyl-methyl-sulfide molecule, attached by one of its atoms—this atom would act as a “pivot”—to an underlying copper surface. And its function entailed spinning around on its pivot whenever the researchers transmitted an electric current through it. Its spinning may sound like the CNRS-Ohio nanomotor, but this Tufts motor’s spin was a simpler spin involving only a singular molecule spinning, with no blades or other such additional parts involved.

Two months later, scientists from Switzerland’s Federal Laboratories for Materials Science and Technology (Empa) and from the Netherland’s University of Groningen created a molecule-sized electric motor that would literally “drive” across a copper surface by means of four rotating atoms that served as “wheels.” An impressive nanotech feat, for sure, and a clear leapfrog over the Tufts motor—the team has essentially built the smallest car on Earth! But it was a limited car, at best, in that the whole structure consisted of a single molecule. And the “wheels” could only move in one direction—i.e., forward.

The CNRS-Ohio nanomotor is groundbreaking in its sophistication and, simultaneously, its size: It really packs a lot of functionality into that mere 2-nanometer length.

“They (the researchers) have reached the lower-most limit for a device capable of converting energy into rotation movement,” states the CNRS press release.

What a Difference a Decade Makes

This latest nanomotor is even more remarkable when we consider that it was only a decade ago that the first-ever nanomotor made its debut. In 2003, a University of California-Berkeley team constructed a nanotube with a gold rotor that would slide along it on the back of a virus.

The device was big by today’s standards, measuring 500 nanometers across and 10 nanometers in width, while the rotor measured somewhere between 100 and 300 nanometers. Now, get ready for the punch line: The team said at the time that they hoped to eventually reduce the nanomotor’s size by a factor of five.

Reduce a 500-nanometers-long contraption by five and, theoretically, you’ll have one that measures 100 nanometers across. That probably was an ambitious goal then. But flash forward to 2013, and behold, this French-U.S. team gives us a nanomotor that not only trumps the UC-Berkeley device in function, but is 2 nanometers across—i.e., a 250-fold reduction.

It’s the kind of story that we would all like to hear more of: Scientists set a goal for a fledgling technology, and a few years later have not only met it, but have surpassed it by a triple-digit factor.

The More Important Point

Now consider: If we can so outdo our own expectations in the nanomotor arena, then why couldn’t we likewise attain unexpectedly lofty heights with other technologies, such as renewable energy? Lots of analysts like to speculate on how many kilowatts a solar array might generate by 2050, and at what cost per kilowatt it will do so. Some analysts offer very optimistic projections; others, some very pessimistic ones. All, however, suffer from this fatal flaw: They are attempting their guesses based on the technologies of today. Tomorrow’s technologies could—in fact, should—be immensely more capable and manage levels of functioning that today’s hardware could never touch.

So where does this leave us—is estimating technological evolution an exercise in futility? Absolutely not: One can, actually, make some fairly spot-on projections about where technology will go. Tech-savvy futurists such as Bill Halal and Ray Kurzweil have been demonstrating this for the last few decades. But what it all does mean is this: When projecting, don’t be afraid to project BIG.