Outlawed now in some places, or only available to tote your purchases at a ridiculous premium, the billions of “T-shirt” bags used every year present a serious waste management problem. Whether blowing across the landscape like synthetic tumbleweeds, floating in the ocean as ersatz jellyfish, or clogging up municipal waste streams, finding a way to deal with them could really make a difference. And finding a bug that eats polyethylene and poops antifreeze might be a great first step in bioremediating the mess.
As with many scientific discoveries, learning about the useful and unexpected eating habits of the larval stage of the Greater Wax Moth Galleria mellonella can be chalked up to serendipity. It began when biochemist [Federica Bertocchini] cleaned a wax moth infestation from her beehive. She put the beeswax-loving pests in a plastic bag, later finding they had chewed their way out. Intrigued, she and [Paolo Bombelli] ran some experiments using the bugs. They showed the mechanism wasn’t just mechanical and that the worms were digesting the polyethylene, to the tune of 92 mg consumed for 100 worms in 12 hours. That’s about 1,000 times faster than bioremediation with bacteria.
Furthermore, the bugs excrete ethylene glycol, a useful industrial chemical, in the process. Finally, to see if the process can scale, the researchers showed that a homogenate of wax moth larvae could digest PE sheets. This could lead to an industrial process if the enzymes involved can be isolated and engineered. The letter describing the process is a fascinating read.
While this one may not a classically hackish way to deal with plastic recycling, the potential for this method is huge. We look forward to seeing where this goes.
[Images: César Hernández/CSIC]
This one is both wild enough to be confused as a conspiracy theory and common sense enough to be the big solution staring us in the face which nobody realized. Until now. Oak Ridge National Laboratory and General Electric (GE), working on a grant from the US Department of Energy (DOE), have been playing around with new clothes dryer technology since 2014 and have come with something new and exciting. Clothes dryers that use ultrasonic traducers to remove moisture from garments instead of using heat.
If you’ve ever seen a cool mist humidifier you’ll know how this works. A piezo element generates ultrasonic waves that atomize water and humidify the air. This is exactly the same except the water is stored in clothing, rather than a reservoir. Once it’s atomized it can be removed with traditional air movement.
This is a totally obvious application of the simple and inexpensive technology — when the garment is laying flat on a bed of transducers. This can be implemented in a press drying system where a garment is laid flat on a bed or transducers and another bed hinges down from above. Poof, your shirt is dry in a few seconds.
But individual households don’t have these kinds of dryers. They have what are called drum dryers that spin the clothes. Reading closely, this piece of the puzzle is still to come:
They play [sic] to scale-up the technoloogy to press drying and eventually a clothes dryer drum in the next five months.
We look at this as having a similar technological hurdle as wireless electricity. There must be an inverse-square law on the effect of the ultrasonic waves to atomize water as the water moves further away from the transducers. It that’s the case, tranducers on the circumference of a drum would be inefficient at drying the clothing toward the center. This slide deck hints that that problem is being addressed. It talks about only running the transducers when the fabric is physically coupled with the elements. It’s an interesting application and we hope that it could work in conjunction with traditional drying methods to boost energy savings, even if this doesn’t pan out as a total replacement.
With a vast population, cost adds up fast. There are roughly 125 M households in the United States and the overwhelming majority of them use clothes dryers (while many other parts of the world have a higher percentage who hang-dry their clothing). The DOE estimates $9 billion a year is spent on drying clothes in the US. Reducing that number by even 1/10th of 1% will pay off more than tenfold the $880,000 research budget that went into this. Of course, you have to outfit those households with new equipment which will take at least 8-12 years through natural attrition, even if ultrasonics hit the market as soon as possible.
Continue reading “A Cool Mist that Dries Your Clothes”
There’s a big to-do going on right now in Germany over particulate-matter air pollution. Stuttgart, Germany’s “motor city” and one of Dante’s seven circles of Hell during rush hour, had the nation’s first-ever air pollution alert last year. Cities are considering banning older diesel cars outright. So far, Stuttgart’s no-driving days have been voluntary, and the change of the seasons has helped a lot as well. But that doesn’t mean there’s not a problem.
But how big is the issue? And where is it localized? Or is particulate pollution localized at all? These questions would benefit from a distributed network of particulate sensors, and the OK Lab in Stuttgart has put together a simple project(translated here) to get a lot of networked sensors out into the wild, on the cheap.
The basic build is an ESP8266 with an SDS011 particulate sensor attached, with a temperature and humidity sensor if you’re feeling fancy. The suggested housing is very clever: two 90° PVC pipe segments to keep the rain out but let the dust in through a small pipe. The firmware that they supply takes care of getting the device online through your home WiFi. Once you have it running, shoot them an e-mail and you’re online. If you want help, swing by the shackspace.
We love these sort of aggregated, citizen-science monitoring projects — especially when they’re designed so that the buy-in is low, both in terms of money spent and difficulty of getting your sensor online. This effort reminds us of Blitzortung, this radiation-monitoring network, or of the 2014 Hackaday-Prize-Winning SATNOGS. While we understand the need for expensive and calibrated equipment, it’s also interesting to see how far one can get with many many more cheap devices.
Nobody is likely to confuse it with the beautiful joinery that makes fine furniture so desirable. But as a practical technique, using plastic bottles as heat-shrink tubing for composite joints is pretty nifty, and the pieces produced are not without their charm.
Undertaken as an art project to show people what can be done with recycled materials, [Micaella Pedros]’ project isn’t a hack per se. She started with bottles collected around London and experimented with ways to use them in furniture. The plastic used in soda and water bottles, polyethylene terephthalate (PET), turns out to shrink quite a bit when heated. Rings cut from bottles act much like large pieces of heat-shrink tubing, but with more longitudinal shrinkage and much more rigidity. That makes for a great structural component, and [Micaella] explored several ways to leverage the material to join wood. Notches and ridges help the plastic grip smoother pieces of wood, and of course the correct size bottle needs to be used. But the joints are remarkably strong – witness the classic leaning-back-in-a-chair test in the video below.
Its aesthetic value aside, this is a good technique to file away for more practical applications. Of course, there are plenty of ways to recycle soda bottles, including turning them into cordage or even using them as light-pipes to brighten a dark room.
Continue reading “Soda Bottles Used as Heat-Shrink for Wood Joinery”
Bees are a crucial part of the ecosystem – without bees to act as pollinators, many plant species wouldn’t be able to reproduce at all! It’s unfortunate then that bees are struggling to survive in many parts of the world. However, [Louise Cosgrove] is doing her part – building homes for bees in old television sets.
The project started when Louise’s son-in-law left 100 (!) analog TVs at her home, having already recycled the picture tubes. That sounds kind of impolite to us, but we’ll give them the benefit of the doubt and assume they had some sort of agreement. [Louise] realised the empty television cases had plenty of ventilation and would make ideal homes for bees. By filling the empty boxes with natural materials like wood, bamboo and bark, it creates nesting places that the bees can use to lay their eggs.
We’ve seen bees on Hackaday beefore (tee-hee) – like this beehive wired for remote monitoring.
[Thanks to Stuart Longland for the tip!]
[Nils Ferber] is a product designer from Germany. His portfolio includes everything from kitchen appliances to backpacks. One project, though, has generated a bit of attention. It’s a micro wind turbine aimed at long distance hikers.
Even on the trail, electronics have become a necessity. From GPS units to satellite phones, to ebook readers. Carrying extra batteries means more pack weight, so many hikers utilize solar panels. The problem is that when the sun is up, hikers are on the move – not very conducive to deploying a solar array. The Wind, however, blows all through the night.
[Nils] used carbon fiber tube, ripstop nylon, and techniques more often found in kite building to create his device. The turbine starts as a small cylindrical pack. Deploying it takes only a few minutes of opening panels and rigging guy wires. Once deployed, the turbine is ready to go.
While this is just a prototype, [Nils] claims it generates 5 Watts at a wind speed of 18 km/h, which can be used to charge internal batteries, or sent directly to any USB device. That seems a bit low for such a stiff wind, but again, this is just a prototype. Could you do better? Tell us in the comments! If you’re looking for a DIY wind generator on a slightly larger scale, you could just build one from bike parts.
Continue reading “Micro Wind Turbine For Hikers”
Depending where you are in the world, the techniques used to build houses can sometimes seem to be stuck in another century. Bricks and mortar, for instance, we build with them because we are used to them and have a large workforce of people trained to work with them and not much else. But in the 21st century with more advanced building technologies sitting relatively unused and looming housing crises at every turn, does it make sense to still build houses the slow and expensive way our great-grandparents did? Probably not.
Wooden houses are a promising solution to some of the problems outlined in the previous paragraph, and indeed in large parts of the world wood is the housing material of choice. It’s eco-friendly, not too expensive, and can be applied easily to multiple different types of structure. If you think of a wooden house, does the image of a log cabin come to mind, or perhaps a weatherboard house? Both construction methods that would be familiar again to your great-grandparents, so perhaps you might not call it an advanced building technology.
It’s interesting then to see an innovation from France, a system of interlocking wood sections that can be built into walls that look very similar to brick (Here’s the French language original). These are short sections of board cleverly designed with dovetailing to engage with vertical sections that interlock between different courses and leave a gap between wooden inner and outer faces of the wall that can be filled with insulation material. The effect is to create a wooden building system that can produce a vast range of structures that can be assembled in a very short time indeed. This isn’t prefabricated housing, but it delivers the speed you’d expect from it.
They have a video shoving construction of a typical house in rather idyllic French countryside, which we’ve put below the break. It has French language annotations, however for non Français speakers the context is pretty obvious.
Continue reading “Modern Wooden Houses With No Glue Or Nails”