Even though the majority of the Earth is covered in water, a surprising number of people around the world don’t have easy access to clean drinking water. The oceans of course are full of salt, and it is difficult to filter that salt out. Researchers at the University of Manchester have found a way to improve a graphene-based filter mechanism that could help convert sea water to potable water.
Pure graphene can do the job, but it is difficult to manufacture in commercial quantities. In addition, the membrane requires the creation of tiny holes, further complicating the production. The new method uses graphene oxide, which is very simple to make and deploy.
Continue reading “Graphene Desalinates Sea Water”
Of all the fictional cyborgs who turn against humanity to conquer the planet, this is as far from that possibility as you can get. These harmless mushrooms seem more interested in showing off their excellent fashion sense with a daring juxtaposition of hard grid lines with playful spirals. But the purpose of this bacteria-fungus-technology hybrid is to generate electricity. The mushrooms are there to play nurse to a layer of cyanobacteria, the green gel in the photo, while the straight black lines harvest electricity.
Cyanobacteria do not live very long under these kinds of conditions, so long-term use is out of the question, but by giving the cyanobacteria somewhere it can thrive, the usefulness grows. The interplay between bacterial and supportive organics could lead to advances in sensors and hydrogels as well. At some point, we may grow some of our hardware and a green thumb will be as useful as a degree in computer science.
Hydrogels could be the next medical revolution, and we’ve already made hydrogels into tattoos, used them as forms for artificial muscles, and hydrogels can be a part of soft tissue printing.
Some of the creepy-crawlers under our feet, flitting through the air, and waiting on silk webs, incorporate metals into their rigid body parts and make themselves harder. Like Mega Man, they absorb the metals to improve themselves. In addition to making their bodies harder, silk-producing creatures like worms and spiders can spin webs with augmented properties. These silks can be conductive, insulating, or stronger depending on the doping elements.
At Italy’s University of Trento, they are pushing the limits and dosing spiders with single-wall carbon nanotubes and graphene. The carbon is suspended in water and sprayed into the spider’s habitat. After the treatment, the silk is measured, and in some cases, the silk is significantly tougher and surpasses all the naturally occurring fibers.
Commercial spider silk harvesting hasn’t been successful, so maybe the next billionaire is reading this right now. Let’s not make aircraft-grade aluminum mosquitoes though. In fact, here’s a simple hack to ground mosquitoes permanently. If you prefer your insects alive, maybe you also like their sound.
Thank you for the tip, [gippgig].
It is sort of an electronics rule 34 that if something occurs, someone needs to sense it. [Bblorgggg], for reasons that aren’t immediately obvious, needs to sense ants moving over trees. No kidding. How are you going to do that? His answer was to use graphene.
Actually, his super sensitive sensors mix graphene in Silly Putty, an unlikely combination that he tried after reading (on Hackaday, no less) about similar experiments at Trinity College resulting in Gputty. The Gputty was highly sensitive to pressure, and so it appears is his DIY version called Goophene. At Trinity they claimed to be able to record the footsteps of a spider, so detecting ant stomping didn’t seem too far-fetched. You can see a video of the result, below.
Continue reading “DIY Graphene Putty Makes Super Sensitive Sensor”
Graphene has attracted enormous interest for electrically detecting chemical and biological materials. However, because the super material doesn’t act like a normal semiconductor, transistors require multiple layers of the material, and that’s bad for 1/f noise especially when the transistors operate at maximum transconductance. Researchers have found a way to operate graphene transistors at a neutral point, significantly reducing 1/f noise while not impacting the sensor’s response.
The team created a proof-of concept sensor that could detect an HIV-related DNA hybridization. The sensor was able to detect very tiny concentrations of the material.
Continue reading “Graphene Biosensors are Extra Quiet”
Graphene is an interesting material, but making enough of the stuff to do something useful can be a little tough. That’s why we’re always on the lookout for new methods, like this electrochemical process for producing graphene in bulk.
You probably know that graphene is a molecular monolayer of carbon atoms linked in hexagonal arrays. Getting to that monolayer is a difficult proposition, but useful bits of graphene can be created by various mechanical and chemical treatments of common graphite. [The Thought Emporium]’s approach to harvesting graphene from graphite is a two-step process starting with electrochemical exfoliation. Strips of thin graphite foil are electrolyzed in a bath of ferrous sulfate, resulting in the graphite delaminating and flaking off into the electrolyte. After filtering and cleaning, the almost graphene is further exfoliated in an ultrasonic cleaner. The result is gram quantity yields with very little work and at low cost.
There’s plenty of effort going into new methods of creating graphene these days, whether by barely controlled explosions or superheating soybean oil. But will graphene be the Next Big Thing? The jury is still out on that.
Continue reading “Graphene from Graphite by Electrochemical Exfoliation”
One of the biggest problems for prosthetic users is feel. If you’ve ever tried to hold a pen and write with a numb hand, you’ve realised how important feedback is to the motor control equation. Research is ongoing to find ways to provide feedback from prosthetic limbs, in even a basic format. The human nervous system is a little more complex than just interfacing with the average serial UART. One of the requirements of many feedback systems is power, which usually would involve bulky batteries or some form of supercapacitors, but a British team has developed a way to embed solar cells in a touch-sensitive prosthetic skin.
The skin relies on everyone’s favourite material of the minute, graphene. A thin layer of graphene allows the prosthetic to feed signals back to the user of both temperature and contact pressure. The trick is that the graphene skin is incredibly transparent, reportedly allowing 98% of light on its surface to pass through. It’s then a simple matter of fitting solar panels beneath this skin, and the energy harvested can then be used to power the sensor system.
The team does admit that some power storage will later be required, as it would be difficult for any prosthetic user if their limbs lost all feedback when they walked into a dark room. The idea of one’s arm losing all feeling upon going to bed isn’t particularly appealing. Check out the paper here (paywalled). Video below the break.
We see a lot of great prosthetic projects cross our desk here at Hackaday – like this 3D printed prosthetic hand. Prosthetics definitely matter, so why not build your own and enter it in the 2017 Hackaday Prize?
Continue reading “Solar-Powered Prosthetic Skin”