Failure Friday

Most people tend to post about projects that go well, but today I am going to post about a project that totally did not work. I have been looking at this electronic origami project for a long time. It looks great, right? A flapping origami bird, what's not to love?

In my first attempt at a wing, I did not measure the resistance of the circuit before I connected the 9 V battery. It turns out the resistance was quite low, and I burned out my first piece of shape-memory wire. For the second wing, I measured the resistance of the wing and used V = IR to ensure that the current would be appropriate (~300 mA). My second wing worked! When I connected the 9 V battery, the wing flapped just like it was supposed to (excuse the cat meowing in the video).

After I got one wing working, I created the other wing and tested the circuit as a whole. Unfortunately, that was as far as this project went. I spent a lot of time checking connections and solder joints, measuring resistances, and tensioning the shape-memory wire. I can see the shape-memory wires move a little, but the wings definitely do not flap. It may be that the total resistance is too high (though measurements and calculations indicate that it should be ok). The only thing I have done differently is that I did not have any silver crimp beads, so I anchored the shape-memory wire with conductive tape.  This may be the problem, but I'm not sure I want to invest any more cash into this project.

Summary: This project looks really cool, but it isn't easy to get it to work. Probably not a great idea for K-12 students, definitely not for students below high school.