Metals Tech

For the third year in a row, the Physics & Tech classes from Roxbury High School in New Jersey, participated in the Trans-Options Hydrogen Fuel Cell Challenge at New Providence High School.

Under the guidance of teachers Michael Gottfried and Ryan Gibson, students from their classes designed and built cars to race in the challenge.

The challenge requires students to design, build and race alternative energy model cars. In the process of designing their car, students learn about fuel cell technology. They also are required to submit a documentation portfolio, which presents the team’s concepts, designs, and comments.

The benefits of the challenge for students include an introduction to STEAM career fields in engaging ways, learning collaborative problem-solving and career-relevant skills. For the teachers, they experience making science and engineering interesting for students, increase student engagement in the STEAM field, and have a life-changing impact by coaching and supporting a STEAM team. Additionally, everyone learns more about the environmental and sustainability impact as they explore using alternative sources of energy.

Denise Glenn, Grades 6-12 Science Supervisor shared, “Our students did an outstanding job placing 5th overall in speed out of 35 teams this year. This is the best RHS has ever placed. We are extremely proud of all of our teams and even received compliments from Trans-Options on our sportsmanship and willingness to assist other schools. Another great day to be a Gael, our P & T classes did an outstanding job this year!”

Of all the strange things we do as a race on this planet, refining and over-complicating things are some of them. We’re never satisfied with letting things be and often time favor extravagant conspiracy theories over reality. After all, how would the opposing piston engine and the convoluted internal combustion engine system have worked until now otherwise? Even though it has brought us this far, we need to get rid of inefficiency for more effective solar thermal energy storage systems.

So, How About Turning Sunshine Into Liquid Fuel For Solar Thermal Energy Storage?

The thought of turning sunshine into liquid fuel might sound like a step back, but hear me out. The solar thermal energy storage system I’m referencing uses a liquid isomer to store and release solar energy. The discovery could lead to more widespread use of solar energy throughout the world, according to the researchers behind it.

According to BigThink, Swedish scientists from the Chalmers University of Technology figured out that using a norbornadiene compound that reacts to sunlight has some potential in this regard. It rearranges its carbon, hydrogen, and nitrogen atoms, which can be stored in an energy-storing isomer called a quadricyclane. Quadricyclanes hold up to 250 watt-hours of energy per kilogram, even after cooling down for a long time. And they doesn’t break down after being recycles.

One of the biggest energy problems for northern and southern countries is with the harvesting and storing of their vast solar energy. These countries have made great strides with hydro and thermal energy systems, but solar thermal energy storage is still a developing field. By using a cobalt-based catalyst, the energy is released as heat, much like how concentrated solar molten salt tanks work. This makes solar energy transportable and a contender for on-demand energy needs.

Getting The MOST Out Of the Molecular Solar Thermal Energy Storage

In a journal article released, the team explains how it was able to release the heat in a macroscopic molecular solar thermal energy storage system, called MOST.

The system works using a solar thermal collector with a pipe that transports the fuel to be transformed into quadricyclane. It then flows into storage tanks and can be shipped anywhere. The site explains it as “a photoswitchable parent molecule that absorbs sunlight undergoes a chemical isomerization to a metastable high energy species.”

More Ways To Store The Sun’s Energy Than We Can Imagine

There are more ways to store the sun’s energy than we can imagine, and all have their pros and cons. By harvesting solar thermal energy and shipping anywhere worldwide, energy needs can be met basically in any location on the planet — and beyond. But this raises a question. It reminds me of the petroleum business model — drilled in specific places and shunted throughout the world. We can only hope that as solar thermal energy storage picks up international interest, it will be as decentralized and removed as far away from concentrated interests as possible.

In the meantime, congratulations to Kasper Moth-Poulsen for making the MOST out of this solar thermal energy storage system.

The interior of a wristwatch is a bit of a love story.

This is where energies from separate coiled springs meet and repel before they harmonize; where escaping frisson from their tango transforms to the measurement of minutes.

Energy within a watch interior is released via a coiled spring, then controlled by gear wheels and a device called an ‘escapement’ that basically transforms analog excitation into digital ticks. This device controls the flow of energy in a timepiece, much—though more intricately—as a bottleneck regulates the flow of sand through an hourglass. A separate coil, the internal balance spring, controls oscillation rates that propel the hands of a watch forward. This meshing of energies—kinetic and potential—between the main spring and balance spring is what drives the dance of time.

Yet the impetus to strap accurate time pieces onto wrists came not from some global infatuation with punctuality or any burning desire to acquire utilitarian jewelry. It originated from desires, both military and commercial, to gain advantage in exploring oceans. Knowing latitude—a ship’s position along an imaginary east-west line—was historically not difficult. But calculating longitude—north to south disposition related to geographical poles—required knowing local times accurately. Because pendulum clocks don’t synch well with roiling seas, and because rewards were offered to those who could create accurate and portable timepieces, precision wristwatches became a grounded reality in the latter portion of the 18th century. The need to accurately pinpoint sea locations is what married timekeeping and ocean travel.

Renowned Swiss born watchmaker Abraham-Louis Breguet spent much of his life in Paris. He produced chronometers for King Louis XVI and for Queen Marie-Antoinette, and during his life increased the overall accuracy of timepieces. For this he became official chronometer-maker to the French navy, and was also appointed to the French Board of Longitude.

Breguet still produces handsome, renowned chronometers. It also maintains an active association with ocean exploration. The focus now, however, is on cleanliness rather than navigational technology. The company is the main sponsor of the Race for Water Foundation—which aims to prevent oceans being polluted with plastics.

Created in 2010 by Swiss entrepreneur Marco Simeoni, Race for Water Foundation’s first maritime expedition found that oceans are not coated in globs of plastic (conducive to being scooped or sucked up like debris) as much as they are soups laden with plastic microparticles, often too small to see. Simeoni described his thoughts regarding cleaning oceans.

I don’t believe in projects cleaning oceans. There is a soup of particles, only of which 10 percent are floating. Boats cleaning oceans will have little impact. So the fight is on land.

Cleaning oceans, then, hinges on preventing plastics from entering their waters. Otherwise, at current rates of pollution, the predicted weight of all plastics in oceans will outweigh that of marine life by the year 2050. At present, about 10 percent of plastics end up in oceans, and probably 25 percent of fish now have plastics inside them. Some of that ends up in human digestive systems.

The current Race for Water Odyssey Expedition is on a five-year global circumnavigation that will last until 2021. It is the only ocean vessel propelled exclusively by three sustainable fuels—all of which can be harvested and harnessed at sea.

The first is solar power. This derives from the boat’s more than 5,500 square feet (500 square meters) of horizontal solar panels that make it resemble a slick insect more than a traditional sail or motor craft. The second comes from wind harnessed by a kite high in the sky. Controlled by an on-board computer that twirls its motion in figure 8’s, this sky kite generates pull. Yet after two days without sunshine, energy in the thousands of pounds of on-board solar batteries becomes depleted. A third energy source then kicks in: hydrogen that is stored in 25 bottles is converted to energy to provide propulsion. This hydrogen (extracted from sea water using energy from the solar panels) can propel the boat for another six days.

Simeoni highlighted what makes this boat unique.

It’s the only boat in the world using those three kinds of sustainable energies. It’s the mix of these three that we are playing with. This boat can now sail indefinitely. The only thing that can stop the boat is if we have some defective components. Without that, we can sail for years and years.

If the key to cleaning plastic pollution is terrestrial, how does a boat propelled by alternative energies address this? It does so two ways. First, it makes stops to educate locals about perils and impacts of discarded plastics on their food supplies, health, and fishing industries. Second, it highlights the benefits of alternative energies, not only those used to propel the boat, but a new technology that is now converting plastics into fuel.

This portable technology named Biogreen includes a patented process from the manufacturer Etia. This converts plastic to a gas which can be converted into energy. Basically, plastic is heated up to 1,470 degrees Fahrenheit (800 degrees Celsius) without oxygen, creating a gas that is then refined to eliminate dust and other pollutants (such as chlorine). The technology is modular and portable, meaning it can be shipped by container to any destination in the world, where it will then process up to 26,000 pounds (12 tonnes) of plastic a day.

Economics drive practicality. That may relate to why the Race for Water Odyssey Expedition is currently island-hopping. Small islands clogged with plastic trash from visiting cruise ships are an ideal target for this technology; local energy costs are high, and space for burying waste on islands is limited.

Simeoni mentioned Rapa Nui, or Easter Island, in the Pacific Ocean.

This island is 3,000 kilometers (1,860 miles) from Chile and 4,000 kilometers (2,500 miles) from Polynesia. The machine costs are amortized over 10 years, and local collectors are paid $100 per tonne of plastics they collect.

The resulting cost of energy from this plastic conversion technology will therefore be about 30 cents per kilowatt-hour. The fact that the current cost of energy on remote Rapa Nui is 70 cents per kilowatt-hour makes it economically viable to implement this Biogreen system. In contrast, energy in Lima, Peru, costs about 10 cents per kilowatt-hour, meaning that this technology would need to be subsidized in that city.

And remember, we are cleaning the land. So Rapa Nui municipality will buy a machine. We’re not recycling; we’re transforming. Recycling is a big challenge. Why? Because there are seven families of plastics that cannot be mixed. Separation costs a lot. Second, you have to clean plastic with still water.

The Biogreen unit requires no separation of plastics. It also has negligible impact on an island’s freshwater resources.

The Odyssey expedition is now in Fiji on a stop during its slow journey westward. Simeoni compared the Race for Water boat to an island.

People are impressed with this unique boat. I say, ‘Hey guys, it’s exactly what you need on your island to make energy: sun, water and wind.’

Although the Race for Water vessel has weathered waves more than 15 feet (5 meters) high, has crossed the Atlantic and is now crossing the Pacific, it is not designed for rough conditions or high speeds (its average speed is five knots; the top speed is 10 knots). Navigators scrutinize weather data and steer toward clear conditions. Because sunshine is critical to generate energy, the boat does not travel too far north or south (Concepción, Chile, was its southernmost stopover). It has a permanent crew of five and enough space within a beautiful interior to host a gathering of up to 80 visitors at one time.

The Race for Water boat is similar to a well-crafted watch: both are self-contained systems that generate their own energy, and their outer beauty cloaks intensely complex inner technology. Such similarities are hard to escape. The combination of watchmakers and ocean navigators once again is propelling improvements in both technology and exploration. Simeoni and the Race for Water team appreciate such support.

We have 25 people working full time for the foundation. Thanks to Breguet we have full support. The best thing that will happen? I can no longer supply machines because there are no plastics in the oceans. Maybe that will happen in 50 years.

Oceans will have changed by then, and technology will be more advanced. Quality chronometers made today, however, may still be ticking accurately.

Last year, researchers at the École polytechnique fédérale de Lausanne (EPFL) in Switzerland developed a new type of transistor — one based on excitons, a special type of quasiparticle — which could be used in the future to make electronic devices smaller, faster, and more efficient. And now the same team has made another breakthrough by discovering new properties of excitons.

An exciton is a subatomic quasiparticle, meaning that it is not a particle in itself, but rather an interaction between two particles. In the case of excitons, they are made up of a bound pair of one electron and one electron hole. (An electron hole is a space in an atom where there is no electron but where one could exist.) The electron and electron hole become linked together when the electron absorbs a photon which gives it a higher level of energy, and the energetic electron moves position and leaves behind an electron hole. The electron is negatively charged and the hole that it leaves behind is positively charged, so the two bond in a process called the Coulomb attraction and form an exciton.

The EPFL team developed a transistor which used excitons instead of electrons. The advantage of this is that the exciton transistor can operate effectively at room temperature, while traditional electron transistors always produce heat when they operate. As transistors are a key component of circuits, having them produce no extra heat would potentially mean a big increase in energy efficiency and no need for large and bulky heat sinks or other cooling in electronic devices.

The latest breakthrough scientists have made is in controlling the properties of excitons. They have found a way to change the polarization of the light generated by the exciton by manipulating a property known as its “valley.” The valley is the maximum and minimum energies that a particle can express, and the valleys of electrons can be used to store information in a field known as “valleytronics” which could extend the ending of Moore’s Law. In the case of excitons, these valleys can be used to code and process information on a minuscule scale.

“Linking several devices that incorporate this technology would give us a new way to process data,” Andras Kis, head of EPFL’s Laboratory of Nanoscale Electronics and Structures, explained in a statement. “By changing the polarization of light in a given device, we can then select a specific valley in a second device that’s connected to it. That’s similar to switching from 0 to 1 or 1 to 0, which is the fundamental binary logic used in computing.”

The simple action of breathing in and out has inspired scientists to create a new technique for generating clean electricity.

Engineers have designed a device that transforms water into fuel, based on the way our lungs work.

One hundred times thinner than a human hair, the gadget splits water into oxygen and hydrogen, which can be used to create carbon-emission free energy.

This method could help existing green energy technologies – including fuel cells – to run more efficiently, researchers say.

These are currently used to power hydrogen busses and cars and could be used to power whole cities in the future.

Stanford University set out to develop better electrocatalysts, materials that increase the rate of a chemical reaction at an electrode – an electrical conductor used in batteries and other energy storage systems.

Experts looked to the lungs for inspiration, in the belief that the breathing apparatus used by mammals is one of the most sophisticated systems for two-way gas exchange found in nature.

With each breath, air moves through the tiny, passage-like bronchioles of the lungs until it reaches small sacs called alveoli.

From there, the gas must pass into the bloodstream without spreading out, which would cause harmful bubbles to form.

It’s the unique structure of the alveoli – including a micron-thick membrane that repels water molecules on the inside while attracting them on the outer surface – that prevents those bubbles from forming and makes the gas exchange highly efficient.

It is this intricate system that the team based their clean energy system around.

‘Clean energy technologies have demonstrated the capability of fast gas reactant delivery to the reaction interface, but the reverse pathway – efficient gas product evolution from the catalyst/electrolyte interface- remains challenging,’ said Professor Jun Li, the first author of the study.

The first part of the process, similar to exhalation, produces hydrogen by passing voltage through water molecules at the electrode of the battery device.

The oxygen and hydrogen produced are transported through a thin membrane, similar to the alveoli of the lungs.

Conventional devices use carbon for this membrane, but the team used an ultra thin polyethylene membrane, which results in a more efficient reaction.

The second stage of the process is more like inhalation and generates energy through a reaction that consumes oxygen.

Oxygen gas is delivered to a catalyst at the electrode’s surface, creating energy as the molecules pass through conductive metals on the inside of the device.

To achieve their aim, the Stanford team made a membrane using plastic film with tiny pores on one side which repel water.

Similar to the way alveoli work, the membrane repels water molecules on the inside while attracting them on the outer surface.

They then sealed the edges to make a small pouch with the metal layer on the inside.

They coated the repelling side with gold and platinum nanoparticles that speed up the chemical reaction.

When they applied a voltage to the water to split it, the hydrogen and oxygen gases are transported through the very thin alveolus-like membrane.

The lung-inspired design is still in the early phases of development and has some room for improvement before it will be ready for commercial use.

Since the ultra thin membrane is made of plastic it cannot tolerate temperatures higher than 100°C (212°F).

‘This could limit its applications,’ said Professor Li.

The team believe this material may be replaced with similarly thin non porous hydrophobic membranes capable of withstanding greater heat.

The full findings of the study were published in the journal Joule.

Hybrid perovskites are spectacularly efficient materials for photovoltaics. Just a few years after the first solar cells were fabricated, they have already achieved solar conversion efficiencies greater than 22 percent. Interestingly, the fundamental mechanisms that are responsible for this high efficiency are still being vigorously debated.

A thorough understanding of these mechanisms is essential to enable further improvements, and computational studies conducted using the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory have produced critical new insights. Chris Van de Walle’s group at the University of California, Santa Barbara (UCSB) has reported these breakthroughs in two recent papers: X. Zhang, J.-X. Shen, W. Wang, and C. G. Van de Walle, ACS Energy Lett. 3, 2329 (2018) and J.-X. Shen, X. Zhang, S. Das, E. Kioupakis, and C. G. Van de Walle, Adv. Energy Mater. 8, 1801027 (2018).

Hybrid perovskites are a group of materials that combine organic molecules with an inorganic framework in a perovskite lattice structure. A number of research groups previously attributed the high efficiency of the hybrid perovskites to an indirect band gap originating from strong spin-orbit coupling. It was argued that the indirect nature of the gap suppresses radiative recombination between electrons and holes and thus minimizes undesirable carrier recombination. UCSB postdoc Xie Zhang and Ph.D. student Jimmy-Xuan Shen (who has since graduated) demonstrated that this was incorrect by developing a cutting-edge, first-principles approach to accurately determine the spin texture of the band edges and quantitatively compute the radiative recombination rates. For methylammonium lead iodide (the prototype hybrid perovskite commonly referred to as MAPI) they found that the radiative recombination is actually as strong as in conventional direct-gap semiconductors.

“This result should put an end to misguided attempts to analyze and design device characteristics based on erroneous assumptions about the recombination rate,” said Zhang.

Strong radiative recombination means that these materials are also useful for light-emitting diode (LED) applications. However, current densities in LEDs are much higher than in solar cells, and at high carrier concentrations nonradiative recombination processes can become detrimental. Such nonradiative losses have been observed, but experimentally it is not possible to identify the microscopic origins. Shen and Zhang built on expertise in the Van de Walle group to accurately compute the recombination rate from first principles. They also managed to precisely link the rate to features in the electronic structure.

“Auger recombination is a process in which two carriers recombine across the band gap and the excess energy is transferred to a third carrier,” explained Shen. “We found that the Auger coefficient in MAPI is unexpectedly large: two orders of magnitude larger than in other semiconductors with comparable band gaps.”

The researchers identified two distinct features of the material that are responsible: a resonance between the band gap and the spin-orbit-induced splitting of the conduction bands, and the presence of structural distortions that promote the Auger process.

“These calculations are extremely demanding, and the compute power provided by NERSC has been instrumental in obtaining these results,” commented Van de Walle. “We have been able to demonstrate that Auger losses can be suppressed if lattice distortions are reduced, and we propose specific approaches for achieving this in real materials.”