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INRS Researchers Develop a New Membraneless Fuel Cell

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Conventional fuel cells are ubiquitous. They power electric cars on today’s roads and were part of the computers used in the 1969 Apollo moon landing. These fuel cells lose voltage as they are used and eventually stop working. This happens because alcohol molecules (methanol or ethanol) in the fuel cell’s anode compartment crossover the membrane separating them from the cathode compartment. Oxygen molecules in the cathode compartment react with the alcohol, causing a drop in voltage.

Numerous scientists have unsuccessfully tried to develop a membrane that stops alcohol molecules from passing through it. Professor Mohamed Mohamedi, a lead author of the study published on September 8, took another tack: developing a fuel cell without a membrane.

His novel solution costs less and requires fewer steps to manufacture, but it fails to address a key challenge. “When the membrane is removed, the methanol or ethanol reacts with the oxygen, just like in conventional fuel cells. To prevent voltage drops, we had to develop selective electrodes in the cathode compartment. These electrodes, designed by doctoral student Juan Carlos Abrego-Martinez, remain inactive in the presence of alcohol molecules but are sensitive to the oxygen that generates electricity,” Professor Mohamedi explains. He notes another unique property of this membraneless fuel cell: it uses oxygen from the air around it.

From Model to Prototype

The first step the researchers took in building a working prototype was to run numerical simulations created by Alonso Moreno Zuria, INRS postdoctoral fellow and a lead author of the study. Through computer modelling, the team tested different configurations of selective electrodes in the fuel cell. “Conventional fuel cells are like sandwiches, with the membrane in the middle. We chose instead to work on a single-layer design. We had to determine how to arrange and space the electrodes to maximize fuel use while keeping ambient air oxygen concentration in mind,” says Professor Mohamedi.

Once the researchers settled on a configuration, they tested a prototype that became a proof of concept. The membraneless fuel cell powered an LED for four hours using only 234 microlitres of methanol. The researchers want to optimize the fuel cell so it can use ethanol, a greener fuel that can be produced from biomass and agricultural waste. Ethanol also provides more power per equivalent unit of volume.

The team expects the fuel cell to power portable electronics such as mobile phones and microsystems such as air pollution sensors. Unlike conventional batteries that store electricity and must be recharged, fuel cells continue to produce energy as long as fuel is available. “This energy supply method is particularly effective when recharging is not possible. Imagine being in the middle of the desert, without electricity. You could recharge your mobile phone using a small capsule of ethanol that you connect to the device,” says Professor Mohamedi.

This pioneering technology has already attracted industry attention even though the research team is only at the prototype stage.

About the study
The researchers received financial support from the Natural Sciences and Engineering Research Council (NSERC), the Quebec Centre for Advanced Materials (QCAM), the UNESCO/MATECSS chair, Consejo Nacional de Ciencia y Tecnología (CONACYT, Mexico), and Científicos Mexicanos en el Extranjero.
https://doi.org/10.1016/j.rser.2020.110045

About INRS

INRS is a university dedicated exclusively to graduate level research and training. Since its creation in 1969, INRS has played an active role in Quebec’s economic, social, and cultural development and is ranked first for research intensity in Quebec and second in Canada. INRS is made up of four interdisciplinary research and training centres in Quebec City, Montreal, Laval, and Varennes, with expertise in strategic sectors: Eau Terre Environnement, Énergie Matériaux Télécommunications, Urbanisation Culture Société, and Armand-Frappier Santé Biotechnologie. The INRS community includes more than 1,400 students, postdoctoral fellows, faculty members, and staff.

 

 

Source:INRS Researchers 

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NASA spacecraft leaking asteroid samples into space is 'victim of own success' – Euronews

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A NASA spacecraft has been so successful in grabbing rubble from an asteroid hurtling through space millions of miles from Earth, that it collected too much and is now spilling its precious cargo back into the void.

In the space agency’s first attempt at taking samples from an asteroid, the spacecraft Osiris-Rex briefly touched asteroid Bennu earlier this week.

But scientists now know it collected far more material than was expected, and its sample container is jammed open.

“We’re almost a victim of our own success here,” said the mission’s lead scientist, Dante Lauretta of the University of Arizona.

Lauretta said there is nothing flight controllers can do to clear the obstructions and prevent more bits of Bennu from escaping, other than to get the samples into their return capsule as soon as possible.

The flight team was scrambling to put the sample container into the capsule as early as Tuesday – much sooner than originally planned – for the long trip home.

Scientists were shocked on Thursday when they saw the pictures coming from Osiris-Rex following its contact with Bennu two days earlier.

A cloud of asteroid particles could be seen swirling around the spacecraft as it backed away from the asteroid.

The situation appeared to stabilise, according to Lauretta, once the robot arm was locked into place but it was impossible to know exactly how much material had already been lost.

The requirement for the mission was to bring back a minimum of 2 ounces (60 grams).

Because of the sudden turn of events, scientists won’t know how much the sample capsule is holding until it’s back on Earth.

The samples won’t make it back until 2023 – seven years after the spacecraft took off.

The complicated €675 million mission, which started with a launch back in 2016, is expected to provide information about the building blocks of the solar system.

They initially planned to spin the spacecraft to measure the contents, but that manoeuvre was cancelled since it could spill even more debris.

Japan, meanwhile, is awaiting its second batch of samples taken from a different asteroid, due back in December.

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NASA probe leaking asteroid samples due to jammed door – Al Jazeera English

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Images beamed back to ground control revealed it caught more material than scientists anticipated and was spewing excess of flaky asteroid rocks into space.

A US probe that collected a sample from an asteroid earlier this week retrieved so much material that a rock is wedged in the container door, allowing rocks to spill back out into space.

On Tuesday, the robotic arm of the probe, OSIRIS-REx, kicked up a debris cloud of rocks on Bennu, a skyscraper-sized asteroid some 320 million kilometres (200 million miles) from Earth and trapped the material in a collection device for the return to Earth.

But images of the spacecraft’s collection head beamed back to ground control revealed it had caught more material than scientists anticipated and was spewing an excess of flaky asteroid rocks into space.

The leakage had the OSIRIS-REx mission team scrambling to stow the collection device to prevent additional spillage.

“Time is of the essence,” Thomas Zurbuchen, NASA’s associate administrator for science, told reporters on Friday.

Zurbuchen said mission teams will skip their chance to measure how much material they collected as originally planned and proceed to the stow phase, a fragile process of tucking the sample collection container in a safe position within the spacecraft without jostling out more valuable material.

NASA will not know how much material it collected until the sample capsule returns in 2023.

The troubleshooting also led mission leaders to forgo any more chances of redoing a collection attempt and instead commit to begin next March the spacecraft’s return to Earth.

“Quite honestly, we could not have performed a better collection experiment,” OSIRIS-REx’s principal investigator Dante Lauretta said.

But with the door lodged open by a rock and the “concerning” images of sample spillage, “we’re almost the victim of our own success here”, he added.

The roughly $800m, minivan-sized OSIRIS-REx spacecraft, built by Lockheed Martin, launched in 2016 to grab and return the first US sample of pristine asteroid materials.

Asteroids are among the leftover debris from the solar system’s formation some 4.5 billion years ago.

A sample could hold clues to the origins of life on Earth, scientists say.

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Asteroid samples escaping from jammed NASA spacecraft – Phys.org

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In this image taken from video released by NASA, the Osiris-Rex spacecraft touches the surface of asteroid Bennu on Tuesday, Oct. 20, 2020. (NASA via AP)

A NASA spacecraft is stuffed with so much asteroid rubble from this week’s grab that it’s jammed open and precious particles are drifting away in space, scientists said Friday.

Scientists announced the news three days after the named Osiris-Rex briefly touched asteroid Bennu, NASA’s first attempt at such a mission.

The mission’s lead scientist, Dante Lauretta of the University of Arizona, said Tuesday’s operation 200 million miles away collected far more material than expected for return to Earth—in the hundreds of grams. The sample container on the end of the robot arm penetrated so deeply into the asteroid and with such force, however, that rocks got sucked in and became wedged around the rim of the lid.

Scientists estimate the sampler pressed as much as 19 inches (48 centimeters) into the rough, crumbly, black terrain.

“We’re almost a victim of our own success here,” Lauretta said at a hastily arranged news conference.

Lauretta said there is nothing can do to clear the obstructions and prevent more bits of Bennu from escaping, other than to get the samples into their as soon as possible.

So, the flight team was scrambling to put the sample container into the capsule as early as Tuesday—much sooner than originally planned—for the long trip home.

“Time is of the essence,” said Thomas Zurbuchen, chief of NASA’s science missions.

This is NASA’s first asteroid sample-return mission. Bennu was chosen because its carbon-rich material is believed to hold the preserved building blocks of our solar system. Getting pieces from this cosmic time capsule could help scientists better understand how the planets formed billions of years ago and how life originated on Earth.

Scientists were stunned—and then dismayed—on Thursday when they saw the pictures coming from Osiris-Rex following its wildly successful touch-and-go at Bennu two days earlier.

A cloud of asteroid particles could be seen swirling around the spacecraft as it backed away from Bennu. The situation appeared to stabilize, according to Lauretta, once the robot arm was locked into place. But it was impossible to know exactly how much had already been lost.

The requirement for the $800 million-plus mission was to bring back a minimum 2 ounces (60 grams).

Regardless of what’s on board, Osiris-Rex will still leave the vicinity of the asteroid in March—that’s the earliest possible departure given the relative locations of Earth and Bennu. The samples won’t make it back until 2023, seven years after the spacecraft rocketed away from Cape Canaveral.

Osiris-Rex will keep drifting away from Bennu and will not orbit it again, as it waits for its scheduled departure.

Because of the sudden turn of events, scientists won’t know how much the sample capsule holds until it’s back on Earth. They initially planned to spin the spacecraft to measure the contents, but that maneuver was canceled since it could spill even more debris.

“I think we’re going to have to wait until we get home to know precisely how much we have,” Lauretta told reporters. “As you can imagine, that’s hard. … But the good news is we see a lot of material.”

Japan, meanwhile, is awaiting its second batch of samples taken from a different asteroid, due back in December.


Explore further

NASA spacecraft sent asteroid rubble flying in sample grab


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