All over the world, mountains of polyethylene terephthalate (PET) plastics are available for recycling in the form of soda bottles. And wherever there is enough cheap raw material, a market is sure to emerge for it. One brilliant inventor in Brazil has decided to capitalize on this market by building a magnificent factory to turn PET bottles into threads, rope, and other products.
Not a word of English is spoken in the video, and our Portuguese stops at obrigado, but you don’t really need to understand what’s being said to know what’s going on. Built from what looks to be the running gear of several bicycles and motors from various cast-off appliances, our nameless genius’ machines slit the PET bottles into fine threads, winds the thread onto spools, and braids the threads into heavier cords. We love the whole home-brew vibe of the machines; especially clever is the hacked desk calculator wired to a microswitch to count revolutions, and the salvaged auto jack used to build a press for forming the broom heads. All in all it’s a pretty amazing little factory cranking out useful products from zero-cost raw material.
We’d love to have more context about what’s being said in the video, so we’ll put this one out there for our Portuguese-speaking readers. Maybe we can get a partial translation in the comments? If so, then obrigado.
Scientists at the George Washington University have managed to figure out a process in which they can literally grow carbon nanofibers out of thin air, using solar power.
Not only that, they do it using carbon dioxide — you know, that gas that contributes heavily to climate change? Using two electrodes, they pump power into a mixture of molten salt; lithium carbonate and lithium oxide. Then, carbon dioxide from the air reacts with the lithium oxide, producing carbon nanofibers — with more lithium carbonate and oxygen as byproducts.
The carbon nanofibers can then be used for a wide range of products or further processes. But beyond getting a useful material out of it, getting rid of carbon dioxide, if done on a large scale, could be beneficial for climate change. Unfortunately, they haven’t figured out how to do that just yet…
Continue reading “And For My Next Trick, I’ll Be Pulling Carbon Nanofibers out of Thin Air!”
Wow. Looking to live off the grid in style? [Jono Williams] just finished off his rather ambitious Skysphere project.
Using industrial materials (is that highway lamp post tower?), [Jono] designed and built his ultimate apartment tower out in the country. Kind of looks like a futuristic outlook or security post — something straight out of that [Tom Cruise] flick, Oblivion.
The project has been in the works for years, and [Jono] estimates its taken about 3000 hours so far — not to mention $50,000 USD in building materials. It’s solar powered, Android controlled, has a fingerprint scanner at the door, an integrated beer fridge in the couch, RGB LED lighting, WiFi, a stargazing platform, a custom queen size bed, his own AI voice, wireless sound, and automated heat management! Continue reading “Living in a Sphere in the Sky”
Too much of a good thing can be a bad thing, and nitrate pollution due to agricultural fertilizer runoff is a major problem for both lakes and coastal waters. Assessing nitrate levels commercially is an expensive process that uses proprietary instruments and toxic reagents such as cadmium. But [Joshua Pearce] has recently developed an open-source photometer for nitrate field measurement that uses an enzyme from spinach and costs a mere $65USD to build.
The device itself is incredibly simple – a 3D printed enclosure houses an LED light source and a light sensor. The sample to be tested is mixed with a commercially available reagent kit based on the enzyme nitrate reductase, resulting in a characteristic color change proportional to the amount of nitrate present. The instrument reads the amount of light absorbed by the sample, and communicates the results to an Android device over a Bluetooth link.
Open-source instruments like this can really open up educational opportunities for STEM groups to get out into the real world and start making measurements that can make a difference. Not only can this enable citizen scientists and activists, but it also opens the door for getting farmers involved in controlling nitrate pollution at its source – knowing when a field has been fertilized enough can save a farmer unnecessary expense and reduce nitrate runoff.
There are a lot of other ways to put an open-source instrument like this to use in biohacking – photometery is a very common measuring modality in the life sciences, after all. We’ve seen similar instruments before, like a DIY spectrophotometer, or this 2015 Hackaday Prize entry medical tricorder with a built-in spectrophotometer. Still, for simplicity of build and potential impact, it’s hard to beat this instrument.
There are many different ways to keep your plants watered on a schedule. [Luca Dentella] just created a new one by building the irrighino watering system. He used standard off the shelf, hardware to keep it simple. Irrighino is a complete watering system based on the Arduino Yun, featuring a user friendly AJAX interface. This allows scheduling in a manner similar to creating appointments in Outlook. It’s also possible to manually control the various water solenoids. The code is fully customizable and open source, with code available from [Luca’s] github repository. The web interface is divided in to three tabs – “runtime” for manual control, “setup” to configure the scheduling, and “events” to view system logs.
The Arduino Yun activates solenoid valves via a relay shield. A switch panel has indicator Status LED’s and three position switches. These allow the outputs to be switched off or on manually, or controlled via the Yun when in auto mode. [Luca] describes how to read three states of the switch (On-Off-On) when connected to a single analog input of the Arduino. He’s also got another tutorial describing how to connect a USB WiFi adapter to the Yun. This is handy since the Yun is mounted inside an enclosure where the signal strength is very weak. While the Yun has on-board WiFi, there is no possibility to attach an external antenna directly to the test SMA socket.
One interesting part is the commercial rain sensor. It’s a switch surrounded by a spongy material. When this material absorbs rain water, it begins to expand and triggers the switch. The Arduino sees the sensor as a simple digital input.
Check a short demo of his system in the video after the break.
Continue reading “Irrighino, an Arduino Yun Based Watering System”
Look at any list of things to do to make your house less attractive to the criminal element and you’ll likely find “add motion sensing lights” among the pro tips. But what if you don’t want to light up the night? What if you want to use a motion sensor to provide a little light for navigating inside a dark garage? And what if the fixture you’ve chosen is a solar fixture that won’t quite cooperate? If you’re like [r1ckatkinson], you do a teardown and hack the fixture to do your bidding.
[r1ckatkinson]’s fixture was an inexpensive Maplin solar unit with PIR motion sensing, with the solar panel able to be mounted remotely. This was perfect for the application, since the panel could go outside to power the unit, with the lamp and PIR sensor inside. Unfortunately, the solar cell is also the photosensor that tells the unit not to turn on during the day. Armed with scratch pad and pencil, [r1ckatkinson] traced the circuit and located the offending part – a pull-down resistor. A simple resistor-ectomy later and he’s got a solar-powered light working just the way he likes it.
A simple hack, but effective. Seeing off-the-shelf gear modified is always a treat. Of course there’s something to be said for the more home-brew approach to security lighting, too.
One practical use of large switches and indicator lamps is to make a power distribution panel which can be useful when you want to control and monitor the power consumption of numerous devices such as your electronics work bench or amateur radio station. Old-school in appearance and using military surplus electronics, this power distribution panel allows for control of outlet on back. Did I mention I built it when I was 16?
Building it was easy, 120 VAC line enters through a main breaker. It is fed through an AC amp meter (with built-in shunt) then to a line filter. From the line filter it goes to a line voltage meter and filament transformer to power the indicator lamps. This AC line is then bussed out to the circuit breakers. Each breaker controls one outlet on the rear panel. As devices are switched on or off the current draw can be measured. This is well demonstrated in the video overview found after the break.
Be creative. Use military surplus switches, indicators, and other unique looking hardware. Customize to give your preferred mad scientist look while also providing valuable functionality.
Continue reading “Become a Mad Scientist, Build A Power Distribution Panel”