# Tweaking Designs For [Theo Jansen] Walking Machines

We love the look, and most especially the gait, of [Theo Jansen’s] walker designs. We don’t fully understand them or the math behind them. But that could change if we spend enough time studying [Aaron Birenboim’s] body of work. He wants to incorporate the legs in a project so he’s been trying to optimize the Jansen leg design.

The calculations are delivered in a source code package available from his site. To make heads or trails out of the numbers you need a way to visualize them. He has provided that as well in the form of a MATLAB script which shows leg piece design and can even spit out an animated .gif file of the virtual legs in motion.

If you have no idea what we’re talking about make sure to check out [Jansen’s] original creations. We’re also excited to read more about the Klann and Ghassaei linkage designs which [Aaron] talks about in his post.

# Laptop Vs Thermite: Slow Motion Destruction

Years ago we covered using thermite to destroy a hard drive. The idea is that if you melt through the platters, the data is completely unrecoverable.  There are tons of videos of people doing this, but they all have a similar format. There’s a hard drive, with a flower pot or soda can sitting on top full of thermite. They then light this with a strip of magnesium and a torch.

I wanted to do something a little different. I wanted to implement thermite as a self destruct mechanism inside the device. To do this, I had to come up with a way to ignite the thermite. This stuff is very difficult to light. You have to get it really really hot. The easiest way is to use magnesium, which itself isn’t the easiest thing to light.

What I finally landed on was an ignition system that uses model rocket igniters, gun powder, and magnesium to light the thermite.  The model rocket igniter can be set off from the 12v line inside your computer. However, it isn’t hot enough to light magnesium shavings, much less thermite. To get it to work, I needed to add some gunpowder. A small amount of gun powder would get hot enough to light the magnesium shavings, which in turn were hot enough to light the thermite. I had to be careful though, because too much gunpowder would cause a rapid expansion, blowing the thermite everywhere instead of lighting it. You can actually see some red thermite being blown out of the external hard drive and the laptop as the gunpowder ignites.

Effectiveness of external hard drive self destruction:

I wasn’t sure about this one. There isn’t a whole lot of space for thermite and the ignition system inside the box. On top of that, the only space was at the side of the hard drive, where the walls are the thickest. I had no idea if the small amount of thermite I used would penetrate the drive. It did, just barely as you can see in these pictures. It looks as if it pooled in the screw holes  and made it inside. The platters are damaged.

Effectiveness of laptop destruction:

I decided to completely replace the cd rom with thermite. This gave me a ton of space to put things. I was pretty positive this would work. The hard drive is in the center of this laptop, which meant I had to place it on its side for this to be effective. You can see the thermite work its way down toward the drive in the video. As you can see in the pictures below, the drive cover is completely gone and the platters are destroyed. Success!

Since this system can be powered by batteries or the internal power of your computer, it can be put inside a working device only to be used when needed. Obviously it is a ridiculous fire hazard that no one should bother with. It was a fun experiment though and I really feel like it is something that would fit in well in the world of [James Bond]

# Herd Single Cell Organisms With Your Mind

Most project tips involving brainwaves get passed over because it’s hard to make much out of that type of control. This project doesn’t necessarily make progress on the control side on this, but you have to admit that herding life forms with your thoughts deserves a closer look.

[Geva] set up a rig that allows him to interact with paramecium — tiny single cell organism that are happy to swim around all day long. Just like vertebrates they’re not big fans of electric shocks. Run some current through the fluid and they’ll swim toward the negative electrode.

This experiment uses four pencil leads as electrodes. These are driven by an Arduino which reacts to the input from a toy brain wave device. Concentrate in just the right way and they will swim wherever you will them to.

This isn’t quite as involved as cockroach mind control, but it’s every bit as interesting

# Listening To Aircraft Transponders With A Raspberry Pi

Last year’s big hack was software-defined radio; a small USB TV tuner that could listen in on radio broadcasts anywhere between 64 and 1200 MHz. This year, it’s all about the Raspberry Pi, so it’s surprising we’re only just now seeing a mashup of these two pieces of hardware. [Corq] is using a Raspi and RTLSDR TV tuner to listen in on aircraft transponders, and getting a whole bunch of data from aircraft flying overhead.

Even though the ADS-B decoder [Corq] is using is written for OS X, he’s reading the data coming from the USB TV tuner over the network with a program called Dump1090. This program allows [Corq] to attach his SDR to a Raspbery Pi and put it somewhere the antenna will get good reception – an attic, or an outdoor weatherproof case – and stream data to his desktop over a WiFi or network connection.

With a USB TV tuner and a Raspberry Pi, [Corq] is able read the tail numbers, altitude, latitude, longitude, speed, heading, and even the type of aircraft currently flying over his house. That’s cool enough, but the fact that he can effectively do this over the Internet makes it a brilliant hardware mashup.