Tag Archives: microbots

Carbon nanotubes can scavenge energy from environment to generate electricity

A June 7, 2021 news item on phys.org announces research into a new method for generating electricity (Note: A link has been removed),

MIT [Massachusetts Institute of Technology] engineers have discovered a new way of generating electricity using tiny carbon particles that can create a current simply by interacting with liquid surrounding them.

The liquid, an organic solvent, draws electrons out of the particles, generating a current that could be used to drive chemical reactions or to power micro- or nanoscale robots, the researchers say.

“This mechanism is new, and this way of generating energy is completely new,” says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT. “This technology is intriguing because all you have to do is flow a solvent through a bed of these particles. This allows you to do electrochemistry, but with no wires.”

A June 7, 2021 MIT news release (also on EurekAlert), which generated the news item, delves further into the research,

In a new study describing this phenomenon, the researchers showed that they could use this electric current to drive a reaction known as alcohol oxidation — an organic chemical reaction that is important in the chemical industry.

Strano is the senior author of the paper, which appears today [June 7, 2021] in Nature Communications. The lead authors of the study are MIT graduate student Albert Tianxiang Liu and former MIT researcher Yuichiro Kunai. Other authors include former graduate student Anton Cottrill, postdocs Amir Kaplan and Hyunah Kim, graduate student Ge Zhang, and recent MIT graduates Rafid Mollah and Yannick Eatmon.

Unique properties

The new discovery grew out of Strano’s research on carbon nanotubes — hollow tubes made of a lattice of carbon atoms, which have unique electrical properties. In 2010, Strano demonstrated, for the first time, that carbon nanotubes can generate “thermopower waves.” When a carbon nanotube is coated with layer of fuel, moving pulses of heat, or thermopower waves, travel along the tube, creating an electrical current.

That work led Strano and his students to uncover a related feature of carbon nanotubes. They found that when part of a nanotube is coated with a Teflon-like polymer, it creates an asymmetry that makes it possible for electrons to flow from the coated to the uncoated part of the tube, generating an electrical current. Those electrons can be drawn out by submerging the particles in a solvent that is hungry for electrons.

To harness this special capability, the researchers created electricity-generating particles by grinding up carbon nanotubes and forming them into a sheet of paper-like material. One side of each sheet was coated with a Teflon-like polymer, and the researchers then cut out small particles, which can be any shape or size. For this study, they made particles that were 250 microns by 250 microns.

When these particles are submerged in an organic solvent such as acetonitrile, the solvent adheres to the uncoated surface of the particles and begins pulling electrons out of them.

“The solvent takes electrons away, and the system tries to equilibrate by moving electrons,” Strano says. “There’s no sophisticated battery chemistry inside. It’s just a particle and you put it into solvent and it starts generating an electric field.”

Particle power

The current version of the particles can generate about 0.7 volts of electricity per particle. In this study, the researchers also showed that they can form arrays of hundreds of particles in a small test tube. This “packed bed” reactor generates enough energy to power a chemical reaction called an alcohol oxidation, in which an alcohol is converted to an aldehyde or a ketone. Usually, this reaction is not performed using electrochemistry because it would require too much external current.

“Because the packed bed reactor is compact, it has more flexibility in terms of applications than a large electrochemical reactor,” Zhang says. “The particles can be made very small, and they don’t require any external wires in order to drive the electrochemical reaction.”

In future work, Strano hopes to use this kind of energy generation to build polymers using only carbon dioxide as a starting material. In a related project, he has already created polymers that can regenerate themselves using carbon dioxide as a building material, in a process powered by solar energy. This work is inspired by carbon fixation, the set of chemical reactions that plants use to build sugars from carbon dioxide, using energy from the sun.

In the longer term, this approach could also be used to power micro- or nanoscale robots. Strano’s lab has already begun building robots at that scale, which could one day be used as diagnostic or environmental sensors. The idea of being able to scavenge energy from the environment to power these kinds of robots is appealing, he says.

“It means you don’t have to put the energy storage on board,” he says. “What we like about this mechanism is that you can take the energy, at least in part, from the environment.”

Here’s a link to and a citation for the paper,

Solvent-induced electrochemistry at an electrically asymmetric carbon Janus particle by Albert Tianxiang Liu, Yuichiro Kunai, Anton L. Cottrill, Amir Kaplan, Ge Zhang, Hyunah Kim, Rafid S. Mollah, Yannick L. Eatmon & Michael S. Strano. Nature Communications volume 12, Article number: 3415 (2021) DOI: https://doi.org/10.1038/s41467-021-23038-7Published 07 June 2021

This paper is open access.

Science and the movies (Bond’s Spectre and The Martian)

There’s some nanotechnology in the new James Bond movie, Spectre, according to Johnny Brayson in his Nov. 5, 2015 (?) article for Bustle (Note: A link has been removed),

James Bond has always been known for his gadgets, and although Daniel Craig’s version of the character has been considerably less doohickey-heavy than past iterations, he’s still managed to make use of a few over the years, from his in-car defibrillator in Casino Royale to his biometric-coded gun in Skyfall. But Spectre, the newest Bond film, changes up the formula and brings more gadgets than fans have seen in years. There are returning favorites like a tricked out Aston Martin and an exploding watch, but there’s also a new twist on an old gadget that allows Bond to be tracked by his bosses, an injected microchip that records his every move. …

To Bond fans, though, the technology isn’t totally new. In Casino Royale, Bond is injected with a microchip that tracks his location and monitors his vital signs. However, when he’s captured by the bad guys, the device is cut out of his arm, rendering it useless. MI6 seems to have learned their lesson in Spectre, because this time around Bond is injected with Smart Blood, consisting of nanotechnology that does the same thing while flowing microscopically through his veins. As for whether it could really happen, the answer is not yet, but someday it could be.

Brayson provides an introduction to some of the exciting developments taking place scientifically in an intriguing way by relating those developments to a James Bond movie. Unfortunately, some of  his details  are wrong. For example, he is describing a single microchip introduced subcutaneously (under the skin) synonymously with ‘smart blood’ which would be many, many microchips prowling your bloodstream.

So, enjoy the article but exercise some caution. For example, this part in his article is mostly right (Note: Links have been removed),

However, there does actually exist nanotechnology that has been safely inserted into a human body — just not for the purposes of tracking.  Some “nanobots”, microscopic robots, have been used within the human eye to deliver drugs directly to the area that needs them [emphasis mine], and the idea is that one day similar nanobots will be able to be injected into one’s bloodstream to administer medication or even perform surgery. Some scientists even believe that a swarm of nanobots in the bloodstream could eventually make humans immune to disease, as the bots would simply destroy or fix any issues as soon as they arrive.

According to a Jan. 30, 2015 article by Jacopo Prisco for CNN, scientists at ETH Zurich were planning to start human clinical trials to test ‘micro or nanobots’ in the human eye. I cannot find any additional information about the proposed trials. Similarly, Israeli researcher Ido Bachelet announced a clinical trial of DNA nanobots on one patient to cure their leukemia (my Jan. 7, 2015 posting). An unsuccessful attempt to get updated information can found in a May 2015 Reddit Futurology posting.

The Martian

That film has been doing very well and, for the most part, seems to have gotten kudos for its science. However for those who like to dig down for more iinformation, Jeffrey Kluger’s Sept. 30, 2015 article for Time magazine expresses some reservations about the science while enthusing over its quality as a film,

… Go see The Martian. But still: Don’t expect all of the science to be what it should be. The hard part about good science fiction has always been the fiction part. How many liberties can you take and how big should they be before you lose credibility? In the case of The Martian, the answer is mixed.

The story’s least honest device is also its most important one: the massive windstorm that sweeps astronaut Mark Watney (Matt Damon) away, causing his crew mates to abandon him on the planet, assuming he has been killed. That sets the entire castaway tale into motion, but on a false note, because while Mars does have winds, its atmosphere is barely 1% of the density of Earth’s, meaning it could never whip up anything like the fury it does in the story.

“I needed a way to force the astronauts off the planet, so I allowed myself some leeway,” Weir conceded in a statement accompanying the movie’s release. …

It was exceedingly cool actually, and for that reason Weir’s liberty could almost be forgiven, but then the story tries to have it both ways with the same bit of science. When a pressure leak causes an entire pod on Watney’s habitat to blow up, he patches a yawning opening in what’s left of the dwelling with plastic tarp and duct tape. That might actually be enough to do the job in the tenuous atmosphere that does exist on Mars. But in the violent one Weir invents for his story, the fix wouldn’t last a day.

There’s more to this entertaining and educational article including embedded images and a video.

Russia invests in Canadian nanotechnology? and flying microbots

There’s a delegation from RUSNANO (Russian Corporation of Nanotechnologies) making the rounds of Canadian nanotechnology firms in the hopes of finding some worthy investments. Officials from the company have also traveled to Finland, the US, Germany, Israel, and elsewhere as they search for companies to invest in. From the Nanowerk news article,

With $5 billion U.S. to work with, RUSNANO is one of the largest technology capital funds on the planet.

The company’s minimum investment will be $10M and they have an investment horizon of 10 years, contrasting strongly with private sector venture funds which often demand a faster return.

I gather this is a government funding agency since it has a  public policy focus,

The public policy imperative behind RUSNANO, which is only a year old, is to help Russia quickly build nano-production capacity to catch up to other powers, notably Japan and the United States, that have developed capacity in this area. “We lost a bit when our scientists when we were engaged in resolving our political problems and now we have to catch up rapidly,” said [Alexander] Losyukov [senior RUSNANO official].

Compare the $10M minimum investment from a $5B fund with Canada’s National Institute of Nanotechnology’s $20M annual budget, which is partly funded by the federal government. I know the federal government makes other investments but it all seems rather piecemeal when compared to other countries’ more unified and financially substantive approach to nanotechnology research and innovation.

In other news, a flying microbot has been created at the University of Waterloo (Ontario, Canada). It’s not precisely nano but it is pretty interesting. From Science Daily,

The microrobot defies the force of gravity by flying or levitating, powered by a magnetic field. It moves around and dexterously manipulates objects with magnets attached to microgrippers, remotely controlled by a laser-focusing beam.

There are more details here.