Electro-active Polymers

July 1, 2011 by Mike Szczys 22 Comments

What’s that you say? You’ve got rigid materials that change their shape when exposed to electric current? Sign us up for some! Although the fabrication process looks a bit daunting, we love the results of working with electro-active polymers. These are sheets of plastic that can flex by contracting in one direction when the juice is turned on. It has an effect very similar to muscle wire but distributed over a larger area.

From what we saw in the video after the break it looks like this is not the most resilient of materials. Several of the test shots have broken panes, but we’re sure that will improve with time. It looks like there is some info out there about fabricating your own EAP but the processes seem no easier than what’s going on at the research level. We might stick to building our own air muscles until EAP is easier to source for projects.

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Making Your Own Lab Instruments

June 16, 2011 by Mike Szczys 31 Comments

[Andrey Mikhalchuk] is trying to gather a base set of lab instruments. Specifically, he’s looking for hardware that will let him quickly filter solids out of a liquid. He first started by adding a cotton disk to a plastic funnel. It does the job, but when left to gravity it’s quite slow. He needed a way to speed up the flow even when the filter is heavily clogged with particulates.

There’s already a solution to this problem. It’s a glass container called a Büchner Flask. These feature a glass tube coming out from the neck. By hooking a vacuum pump up to this tube, reduced pressure inside the flask will pull the liquid through the filter in no time. Rather than purchase the specialty item, [Andrey] altered a rubber stopper to accept both the funnel, and a glass tube. This is a cheaper version because it uses a common conical flask but it works just as well. To create the vacuum, an altered bike pump was used. Check out videos of both hacks after the break. Continue reading “Making Your Own Lab Instruments” →

Magnetism Makes Silly Putty Fun Again

June 10, 2011 by Mike Szczys 36 Comments

The image above is a screen capture from a video clip where the black ooze gobbles up that rare-earth magnet. It’s actually a blob of Silly Putty which was slightly altered to add magnetic properties. [Mikeasaurus] grabbed some ferric iron oxide powder from an art supply store and donned gloves and a dust mask while massaging it into the silicone polymer. If you get the right mix of the two materials you end up with a flowing substance that performs mysteriously when exposed to a magnetic field.

Check out the video after the break to see some of the tricks that [Mikeasaurus] can do. The putty really looks like it has a life of its own. It will stretch a remarkable distance to get close to the magnets (amorphous stretch). If left in contact with one it will fully engulf it and then form an orb.

Now, is there any way to use this with electromagnetic fields to build a morphing robot?

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Portal Turret Plushie Is Cute And Harmless

April 25, 2011 by Mike Nathan 16 Comments

turret_plushie

As many of you are probably aware, Portal 2 was released last week, and gamers have been going crazy over it. Over the years, people have constructed replicas of their favorite in-game items and “characters”, including portal guns, companion cubes, and turrets.

After playing Portal 2 for a bit, [Jonathan] wanted a turret of his own quite badly. Rather than construct it from hard plastics and resins however, he decided he wanted to construct a cuddly turret that talked.

With the assistance of his friend [Leigh Nunan], he is now the proud owner of a plushie turret. It’s a bit smaller than you might expect, but it is packed full of turret personality. The plushie plays audio from the game, can sense motion near its face, detect if it has been tipped over, and also knows when it has been picked up. [Jonathan] added all of these features by stuffing an Arduino inside the turret, along with a wave shield for playing sounds. Proximity and motion sensing are provided via a trio of different sensors, enabling the turret to behave in the same way its in-game brethren do (minus the machine guns).

It really is a neat little toy, one we would no doubt be glad to have around. Keep reading to see a short video of his plushie turret in action.

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Powering Vehicles With Aluminum

April 19, 2011 by Mike Szczys 83 Comments

Pop a few aluminum bits into this little RC racer and you’ll have power for around forty minutes. This concept, which has been patented, is the result of a college research project. It uses a chemical reaction between aqueous Sodium Hydroxide and aluminum. The result of that reaction is hydrogen, which is gathered and directed to a fuel cell that drives the car.

Novel? Yes. Interesting? Absolutely. But you should be raising an eyebrow at the dubious choice of fuel that is aluminum.

If you don’t know what we’re talking about let us paint you a picture. Aluminum is a metal that is refined from bauxite ore. It takes an immense amount of electricity to smelt the metal. This is usually justified because aluminum is one of the most recyclable substances on earth, capable of being melted down and reformed countless times. But dissolving it in drain cleaner breaks it down and then it’s gone. So what we have here simply must be the least efficient disposable battery so far developed. It’d probably use less resources to grow and harvest lemons as a power source.

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Compost Heap Temperature Logger Helps Keep Things Hot

April 8, 2011 by Mike Nathan 12 Comments

compost_temp_logger

HackHut user [lackawanna] is looking to start his own compost pile, but as many urban composters discover, things can get quite smelly if you don’t manage it properly. The process of composting is broken up into two phases, aerobic and anaerobic decomposition. The former is the first stage to occur and produces plenty of heat, but should be scentless. The latter gives off less heat and is more of a stink due to putrefaction. Carefully monitoring the temperature of the pile and restarting the aerobic phase when necessary helps to keep the process “healthy” and scent-free.

[lackawanna] built a simple temperature monitor that he plans on using to track the status of his compost pile once he gets started. It uses an ATmega328 as the brains of the operation and an old metal can transistor as his temperature sensor. Using relative measurements of the compost pile taken in 10 minute intervals, he can determine when the aerobic phase is underway, as well as when things begin turning anaerobic. At that point, the sensor alerts him that the pile needs to be turned.

The build is pretty simple, but leaves plenty of room for expansion. It should be relatively easy to add a more friendly notification interface as well as install multiple sensors to the pile for obtaining aggregate temperature data.

Toothpaste Diode

March 16, 2011 by Kevin Dady 39 Comments

While reading the back of a tube a toothpaste [Underling] noticed that one of the ingredients was hydrated silica, gears turned, sparks flew and he wondered if he could possibly make a transistor out of the stuff. After thinking about it he decided that making a diode out of toothpaste would be easier and still prove the idea.

The quick n dirty explanation of this is he smeared some toothpaste on a bit of chrome and set it on fire with a propane torch. When set on fire the result is silica and sodium, heat causes the sodium to bond with the silica and since sodium is negatively charged this forms an n-type semiconductor or half of the diode. Chrome is used for the second half of the diode, for a few reasons, he had some lying around, its positivity charged, and the toothpaste contains a little bit of lye which oxidizes the chrome and burns off, bonding the silica to the metal.

What is left is a thin layer of chrome doped silicon under a layer of sodium doped silicon, which in spots where everything is perfect, acts like a diode, blocking current in one direction but not the other.