With this project I wanted to create something akin to a midi controller (but without actually using midi) that could interface with max to modulate a sample sound.  Basically, I wanted something that was aesthetically pretty, and different from the traditional midi controller, as well as portable and not made of hard materials (so it could be easily rolled or bunched and put in a backpack).

I finally ended up getting an interface that worked, but I then had trouble with the max patch.  I would like to retackle the project, both to create a sturdier interface, and a patch that worked better.    Some issues that I ran into with the interface, is that because I used muslin as the fabric, it wrinkles easily, and is hard to hold down.  I think when I remake the interface I’ll use something like neoprene. Also, I used the conductive thread, but that made it hard to run the traces for the arduino, so I ended up using alligator clips.  I think when I redo this project I would either like to experiment with creating copper traces or just cut the circuit out of conductive fabric and adhere it to the fabric.

The way it works, is that each “triangle” is made from resisitive ink, and then connected to ground and an analog input.  The lines of conductive thread between each triangle are then connected to voltage.  When a metal instrument bridges the gap between one of the triangles and the power, a potentiometer/slider is created.  I was inspired by Kobakant’s potentiometer’s here. These analog inputs are then connected to max and used as sliders.  One issue I ran into was that these potentiometers weren’t providing a full range, they were only running between 0 when off to 800 – 1000 when activated.  I assume this was because of their size or the thickness of the ink. I would like to experiment with creating larger triangles, and see if this persists. To get the pattern on the fabric I printed my design onto card stock, cut it out with an xacto knife, sprayed the back with adhesive, and placed it on the fabric as a stencil.  One other very important thing that I learned from this project was the fragile nature of conductive ink.  While the resistive ink doesn’t crack and works very well on fabric, when I tried to create the voltage traces out of conductive ink, they continued to crack.

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Heres an example of the kinds of sounds produced:

All in all it was a great learning experience, and a valuable prototype as I continue with these kinds of hand made interfaces.

My political topic with the thermochromic ink project was planned parenthood.  Basically I wanted to express that since funding to planned parenthood is being cut, many areas will lose their access to sex education and clinics.  I decided to create a composition of an egg, sperm, and a baby that would appear with thermochromic ink.   However, because of the opacities of the inks, the baby is always showing haha.  Also, because I had trouble powering just the area of the poster where the baby is, whenever you heat the poster the whole egg disappears.

The layers are:

1. Back – Copper Tape to Power Unit, Paper PC Board with transistor to allow arduino to control poster.

2. Paper

3. Layer of Conductive ink in the shape of a baby.

4. Layer of Pink thermochromic ink in the shape of an egg.

5. Blue Layer of acrylic ink in the shape of sperms.

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Some important lessons for thermochromic
– quality of print is different from one type of paper to the next.
– user retarder, otherwise you will have to wash your screen out often.
– use lots of transparent base. if you use opaque base the thermochromic will vanish to reveal the opaque color.
– achieving the appropriate level of heat using soft circuits is very difficult.

I also made some shirts.

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Paper speaker boxes that can be stacked to move sound. I am using the ATtiny85 which does not support the tone() function, so the sound is actually a quick PWM hack. More description forthcoming!

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This project (ideally) allows the user to reconfigure the interface to make different patterns. Each triangle was silkscreened with a different temperature threshold thermochromic ink to add to the effect.

Each square is held on by magnets on the corners. Copper tape connects the square to the circuit interface and (again, ideally) allows current to run through it that heats the copper and causes the ink to disappear.

The only problem is the functionality. In constructing the interface, I forgot the most basic electrical concept – it follows the path of least resistance. Most of the current doesn’t even touch two of the squares, and instead passes right by them.

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VELLUM
This vellum (Gilclear Oxford) is one of my favorites to work with. It also happens to have a very nice tension that allows it to vibrate at a frequency that works well for producing sound.

TRACING PAPER
After a few attempts at making a paper speaker with card stock, I realized the faulty logic of using such rigid paper, especially since I am using copper tape which adds weight to it. Tracing paper and copper tape creates a nice suface for vibration.