We’re not quite sure what’s going on with our fellow hackers lately, but they all seem quite interested in finding inventive ways to scramble their brains. [Ben Krasnow] has put together a pair of videos detailing his experiments in transcranial magnetic stimulation, a process that looks like it would go quite nicely with the Brainwave Disruptor we showed you just yesterday.
Instead of building a coil gun with a set of supercapacitors he had on hand, [Ben] decided to build a magnetic coil that can be used to stimulate his brain through his skull. Once his capacitor bank is charged, a high current pulse is sent through the coil held against his head. This pulse generates a strong magnetic field in the coil, which in turn produces neuron stimulation in his primary motor cortex.
Be sure to watch both videos embedded below, as the first one mostly covers the theory behind his experiments, while the second video gives us the goods.
[Ben’s] day job involves working with professional grade TMS devices, so he has some experience with this technology. Before you try this on your own, be sure that you are doing this safely, because a misdirected pulse of 1700 volts to the head does not sound like a fun time at all.
Continue reading “Controlling muscles with high intensity magnetic pulses”
Instructables user [killbox] seems to have come across a process that actually makes magnetic silly putty “better”, depending on your specific needs. He had tons of fun making a batch of magnetic putty, but thought that the addition of iron oxide made it stiff and a bit slow moving for his tastes.
He tried to find a household item that could act as silly putty thinner, but after trying various oils, gylcerin, and rubbing alcohol, he came up empty handed. Undeterred, he researched how silly putty itself is made, and based on its list of ingredients, decided to seek out some sort of silcone-based lubricant.
He headed out to the local sex shop, and spent some time browsing through the “personal lubricant” section, in hopes of finding what he needed. He settled on ”Gun Oil”, a silicone lubricant that also contained Dimethicone, an item on the ingredient list of the lubricant he initially used to make the batch of magnetic putty.
After adding the lubricant, he found that the putty retained its texture, but flowed far more easily. The thinner putty also consumes rare earth magnets more quickly than its unaltered brethren, as you can see in the picture above.
We’re not sure how far you could push the ferro-putty before it would become a mess, but it’s certainly warrants further experiments.
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?
Continue reading “Magnetism makes silly putty fun again”
[svofski] sent us this pick and place robot (Google translation) that he found , and it’s quite unique. The majority of the components that make up this pick and place have been recycled from old computer equipment. The X-axis motion is accomplished using old printer parts, while an old CD-ROM drive was gutted to provide motion along the Y-axis. Floppy drive components were ultimately chosen to give the pick and place Z-axis motility.
What makes this pick and place unique however is the way in which components are moved. Most pick and place devices we have seen rely on suction in order to lift and carry components, but this one uses a magnet instead. The machine is used to build small circuit boards for a robotics platform offered on the builder’s web site, which primarily utilizes SMD parts. Once they realized that the majority of their small components were ferromagnetic, they built a hand-wound electromagnet to lift them. While the design limits the usage of the device to strictly ferromagnetic parts, they have a very specific need, which this fills perfectly.
Another unique aspect of this pick and place is the grooved table that sits under the workpiece. It is used to route up to four reels of SMD components, with the placement head providing all of the reel motion instead of relying on separate motors.
If you have a few minutes, be sure to check out the video of the pick and place at work.
Here’s the proof that Arduino is a tool for serious prototyping and not just a toy. [Norbert Požár] built a magnetic levitation device that combines an Arduino with an electromagnetic driver circuit and a magnetic field sensing circuit. Unlike other other levitation setups that use optical sensing, this implementation uses a hall effect sensor on the electromagnet to maintain the distance between it, and the permanent magnet it is holding in midair. Check out the embedded video after the break and browse through the overview page so see how pleasing it is to do away with a frame around the floating object. This makes us wonder if it could be inverted in a way similar to that magnetic scale.
Continue reading “Arduino levitation”
Cards you should crank
These greeting cards must be the product of a mechanical engineer run amok. They come with a crank and are designed to entertain with their simple, yet elegant movements. [Thanks Phil]
Magnetic card stripe reader
[JP] built an Arduino based magnetic card reader. It uses off-the-shelf parts but if you don’t mind buying the components this will get you up and running in no time. If you want more info there’s also this Teensy based version.
Homemade Airsoft sentry gun
This sentry gun has an amazingly fast firing rate that can continue for quite a while, thanks to the big flashlight housing that is holds a lot of ammo. [Thanks David]
Scanner easter egg
The engineers over at HP had a little fun building an easter egg into this scanner. If you know what you’re doing you can get it to play the Ode to Joy. It needs to join the old-hardware band from our Links post earlier in the month. [Thanks Googfan]
Here’s a hack that makes business sense. [PT] recalls last year’s HOPE conference when their booth was using a virtual credit card terminal for purchases that required manual entry of card information. This year they’ll have the same virtual terminal but this magnetic stripe reader will fill it out automatically.
A magstripe reader (reading only, no funny business here) from Mouser grabs data from the card. A Teensy microcontroller board, which identifies itself as a USB keyboard, automatically fills out the virtual terminal from the parsed data. The real question, are his customers comfortable sliding their plastic through a hacked reader?