Hackaday Prize Entry: Open Source Electrospinning

Electrospinning is the process of dispensing a polymer solution from a nozzle, then applying a very high voltage potential between the nozzle and a collector screen. The result is a very, very fine fiber that is stretched and elongated down to nanometers. Why would anyone want this? These fibers make great filters because of their large surface area. Electrospinning has been cited as an enabling technology for the future of textiles. The reality, though, is that no one really knows how electrospinning is going to become a standard industrial process because it’s so rare. Not many labs are researching electrospinning, to say nothing of industry.

[Douglas Miller] is building his own electrospinning machine. Except for the ominous warning signs on the 40-kilovolt power supply, there’s nothing in this machine that makes it look any different from a normal, homebrew 3D printer. There are stepper motors inside to raise and lower a carriage, a syringe, and a handy USB port. If you didn’t know any better, you could easily assume [Doug]’s OpenESpin is designed to print fidget spinners and tiny tugboats instead of films of carbon nanotubes and piezoelectric thermoplastics.

The DIY electrospinning machine is really what the Hackaday Prize is all about. It’s an enabling technology anyone can build for a few hundred dollars that also allows real science to happen. The films and blobs being formed in [Doug]’s electrospinning machine could easily find a home in a PhD candidate’s thesis or as a component in cutting edge research on everything from battery technology to the Internet of Underpants.

POV Display Does it on the Cheap

lowBudgetPOV

[Sholto] hacked together this ultra low-budget spinning display. He calls it a zoetrope, but we think it’s actually an LED based Persistence Of Vision (POV) affair. We’ve seen plenty of POV devices in the past, but this one proves that a hack doesn’t have to be expensive or pretty to work!

The major parts of the POV display were things that [Sholto] had lying around. A couple of candy tins, a simple brushed hobby motor, an Arduino Pro Mini, 7 green LEDs, and an old hall effect sensor were all that were required. Fancy displays might use commercial slip rings to transfer power, but [Sholto] made it work on the cheap!

The two tins provide a base for the display and the negative supply for the Arduino. The tins are soldered together and insulated from the motor, which is hot glued into the lower tin. A paper clip contacts the inside of the lid, making the entire assembly a slip ring for the negative side of the Arduino’s power supply. Some copper braid rubbing on the motor’s metal case forms the positive side.

[Sholto] chose his resistors to slightly overdrive his green LEDs. This makes the display appear brighter in POV use. During normal operation, the LEDs won’t be driven long enough to cause damage. If the software locks up with LEDs on though, all bets are off!

[Sholto] includes software for a pretty darn cool looking “saw wave” demo, and a simple numeric display. With a bit more work this could make a pretty cool POV clock, at least for as long as the motor brushes hold up!

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Spinning-hell of a game

North Street Labs really brought their ‘A’ game to the build finals for the Red Bull Creation contest. Behold the Centrifury, their spinning hell of a game. You can’t really make it out (because of the spinning) but the game consists of two bucket seats positioned opposite of each other on a merry-go-round type deck. Each player has a button in front of them which must be held down for the rig to start spinning. When you can’t take it any more just release the button and the spinning will stop. But you’ll also have lost the game. Whomever can hold out longer wins.

It’s not surprising to see such a well-polished build. After all, this is the same group that built the violently vibrating game of Simon. This time around most of the work came in the form of engineering and welding. First they had to make sure the design could take the forces this things puts out, then they had to build it. And all within the 72-hour time limit. We’re not sure what’s harder, winning the game or trying not to smile while watching the video after the break.

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