Nanoparticles Rip Hydrogen From Water

Hydrogen fuel is promising, and while there’s plenty of hydrogen in the air and water, the problem is extracting it. Researchers have developed a way to use aluminum nanoparticles to rip hydrogen out of water with no additional energy input. It does, however, require gallium to enable the reaction. The reaction isn’t unknown (see the video below), but the new research has some interesting twists.

Aluminum, of course, is cheap and plentiful. Gallium, not so much, but the process allows recovery and reuse of the gallium, so that makes it more cost-effective. There is a patent pending for the process and — of course — the real trick is making the aluminum nanoparticles. But if you have that, this is a simple way to extract hydrogen from water with no extra energy and at room temperature. Since the reaction of creating aluminum oxide and releasing hydrogen with gallium is pretty well-known, it appears the real research here is determining the optimal properties of the aluminum and the ratio of aluminum to gallium.

While gallium isn’t a common item around the typical hacker’s workshop — unless you count the stuff bound up in semiconductors — it isn’t that expensive and it is relatively easy to handle. Hydrogen, though, not so much — so if you do decide to use this method to produce hydrogen, be careful!

We’ve seen gallium robots and even an antenna. So if you do get some of the liquid metal, there are plenty of experiments to try.

Better Robots Through Gallium

In the movie Terminator 2, the T-1000 robot was made of some kind of liquid metal that could change shape among other interesting things. According to a chemical engineer at North Carolina State University, there may be something to the idea. [Michael Dickey] has been experimenting with gallium, a liquid metal, that scientists think may unlock a new generation of flexible devices.

The most common liquid metal is mercury, of course, and it has its uses. However, its toxicity has led to a reduction in its use. Gallium has low toxicity and also doesn’t easily evaporate. What can you do with it? Check out the video below to see a very simple demonstration of the liquid metal lifting a small — very small — weight with an electrical impulse.

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Silicone Devices: DIY Stretchable Circuits

Flexible circuits built on polyimide film are now commonplace, you can prototype with them at multiple factories, at a cost that is almost acceptable to your average hacker. Polyimide film is pretty tough for something so thin, but eventually it will tear, and with larger components, bend radii are quite restricted. But what about stretchable circuits, as in circuits you can flex, twist and stretch? Let us introduce silicone devices. A research group from Hasselt University, Belgium, have been prototyping making truly flexible, silicone-based circuit substrates, managing to integrate a wide range of SMT component types with a dual layer interconnect, with vias and external contacts.

It should be possible to reproduce the process using nothing more special than your average Makerspace CO2 laser cutter, and a couple of special tools that can be easily made — a guide for that is promised — it is purely a matter of gathering a few special materials, and using off-cuts you have lying around for the rest. The interconnect uses Galinstan, which is a low melting point alloy of gallium, indium, and tin. Unfortunately, this material is fairly expensive and cannot be shipped by air due to the gallium content, without specialised handling, at considerable expense. But that aside, other than some acrylic sheets, some vinyl, copper foil and a few sprays, nothing is beyond reach.

The construction process is reverse to what we normally see, with the components and copper contact plates placed first, on to a primed vinyl sheet. This sheet is laser marked with the component outlines to enable them to be corrected placed. Yes, that’s right, they’re using a laser cutter to mark vinyl, a chlorine-containing plastic. Hold on to that thought for a bit.

Insulating layers and substrate layers are constructed by blade-coating with a layer of clear silicone. Interconnect layers are formed by sticking a fresh vinyl sheet onto the exposed contacts and laser cutting just though it to expose the pads and the interconnect traces. Next the fancy Galinstan is applied by brush and the vinyl stencil removed. Rinse and repeat for the next layer of insulating silicone, more circuit traces, then use the laser cutter to precisely etch through the via regions to allow more metalisation to be added. Finally a coating of silicone is applied over the whole assembly, the laser is again used to etch the silicone away from the contact pads, and with a little solder tinning of these, you’re done. Simple, if only our Makerspaces didn’t have rules against laser cutting vinyl.

This was clearly a very brief overview, here is a very detailed instructables guide ready for you, as well as a formal research paper, detailing why this came about and why you might want to try this yourself.

If you’re into custom wearables, you might remember this earlier piece about silicone circuits, and this one weird organic-looking thing from the same time-frame.

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Circuit Boards You Can Stretch: Liquid Metal Nanomaterials Make A Strange Flex

If you think polyimide-based flexible PCBs are cool, wait until you get a load of what polymerized liquid metal networks can do.

Seems like [CNLohr] has some pretty cool friends, and he recently spent some time with a couple of them who are working with poly LMNs and finding out what they’re good for. Poly LMNs use a liquid metal composed of indium and gallium that can be sprayed onto a substrate through a laser-cut stencil. This results in traces that show the opposite of expected behavior; where most conductors increase in resistance when stretched, pol LMNs stay just as conductive no matter how much they’re stretched.

The video below shows [CNLohr]’s experiments with the stuff. He brought a couple of traditional PCB-based MCU circuits, which interface easily with the poly LMN traces on a thick tape substrate. Once activated by stretching, which forms the networks between the liquid metal globules, the traces act much like copper traces. Attaching SMD components is as simple as sticking them to the tape — no soldering required. The circuits remain impressively stretchy without any apparent effect on their electrical properties — a characteristic that should prove interesting for wearables circuits, biological sensors, and a host of real-world applications.

While poly LMNs aren’t exactly ready for the market yet, they don’t seem terribly difficult to make, requiring little in the way of exotic materials or specialized lab equipment. We’d love to see someone like [Ben Krasnow] pick this up and run with it — it seems right up his alley.

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Aluminium Pucks Fuel Hydrogen Trucks

In the race toward a future free from fossil fuels, hydrogen is rapidly gaining ground. On paper, hydrogen sounds fantastic — it’s clean-burning with zero emissions, the refuel time is much faster than electric, and hydrogen-fueled vehicles can go longer distances between refuels than their outlet-dependent brethren.

The reality is that hydrogen vehicles usually need fuel cells to convert hydrogen and oxygen into electricity. They also need pressurized tanks to store the gases and pumps for refueling, all of which adds weight, takes up space, and increases the explosive potential of the system.

Kurt Koehler has a better idea: make the hydrogen on demand, in the vehicle, using a solid catalyst and a simple chemical reaction. Koehler is the founder of Indiana-based startup AlGalCo — Aluminium Gallium Company. After fourteen years of R&D and five iterations of his system, the idea is really starting to float. Beginning this summer, these pucks are going to power a few trucks in a town just outside of Indianapolis.

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Reducing Carbon Emissions With Coal

It might seem like a paradox, but coal might hold the answer to solving carbon emission problems. The key isn’t burning it, but creating it using carbon dioxide from the atmosphere.  While this has always been possible in theory, high temperatures make it difficult in practice. However, a recent paper in Nature Communications shows how a special liquid metal electrocatalyst can convert the gas into a solid form of carbon suitable for, among other things, making high-quality capacitor electrodes. The process — you can see more about it in the video below — works at room temperatures.

It isn’t that hard to extract carbon dioxide from the air, the problem is what to do with it. Storing it as a gas or a liquid is inefficient and expensive, while converting it to a solid makes it much easier to store or even reuse for practical applications.

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Stretchable Traces For Flexible Circuits

Electronic components are getting smaller and smaller, but the printed circuit boards we usually mount them on haven’t changed much. Stiff glass-epoxy boards can be a limiting factor in designing for environments where flexibility is a requirement, but a new elastic substrate with stretchable conductive traces might be a game changer for wearable and even implantable circuits.

qxMo1DResearchers at the Center for Neuroprosthetics at the École Polytechnique Fédérale de Lausanne are in the business of engineering the interface between electronics and the human nervous system, and so have to overcome the mismatch between the hardware and wetware. To that end, [Prof. Dr. Stéphanie P. Lacour]’s lab has developed a way to apply a liquid metal to polymer substrates, with the resulting traces capable of stretching up to four times in length without cracking or breaking. They describe the metal as a partially liquid and partially solid alloy of gallium, with a gold added to prevent the alloy from beading up on the substrate. The applications are endless – wearable circuits, sensors, implantable electrostimulation, even microactuators.

Looks like progress with flexibles is starting to pick up, what with the conductive silicone and flexible phototransistors we’ve covered recently. We’re excited to see where work like this leads.

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