Thursday, October 11, 2007

ACADIA - Metabolic Workshop


When we arrived in Halifax on Sept. 30 at about 2:00pm in the afternoon. After a 25 minute taxi ride from the airport we arrived at the Architecture Building of Dalhousie University. With it being a Sunday afternoon, the facilities were locked down - so we waited until a very trusting student kindly let us in with all of our bags and belongings. The entry way led us directly to the space in which the Metabolic Workshop was to be held - and there were already a number of people getting started on preparing all of the rope and electronics. This was to become our home for the next 3 days.

The workshop started with a group discussion and introductions of all participants. The brief for the workshop was basically that we were going to turning the mass of rope hanging from the ceiling into some kind of responsive textile environment installation - by impregnating it with motors, electronics, new materials and engineered pieces.

Once introductions and the initial explanations were through, we broke out into smaller groups in order to tackle all of the tasks that would be necessary to complete the installation.
The 3 groups consisted of a group dealing directly with the mass of rope already in place, another group working with servo motors and systems that were to be introduced into the rope-organism, and another group dealing with the electronics/electrical systems. I decided that I would throw myself into what I perceived to be the most difficult task (for myself as I knew basically nothing about circuitry and electronics). I felt it would be a good way to learn, especially having Alan Macy as our team leader. Alan is an electrical engineer from California and has incredible patience in helping people understand the very basics of electronics and circuitry.

In this smaller group I met a guy named Josh Cotten from SOM Chicago. Josh is a really talented guy and he specializes in parametric software and scripting (is that right Josh?). Throughout the day Christine Macy, one the Workshop organizers, began to develop some flower petals using LED's and conductive fabric. We were also introduced to "muscle wire" or Shape Memory Alloy (SMA) or Flexinol or Nitonol... or as I like to call it; "Happy Magic Wire" - an alloy which shrinks roughly 3-5% of its length as an electrical current is passed through it and returns to its original length as it cools.

Josh and I saw an interesting opportunity with the idea of the venus flytrap-like petal and the muscle wire. We took off in our own direction and began to draw up some leveraging systems, with the help of Alan, so that we could create the jaw of the flytrap. You can see (below) our first crude prototype of a scissor-like lever system made out of 3 pieces of stripped bamboo that was lying around. I wish I had better images of the original prototype, it was nice in a very primitive kind of way. It was fashioned together using tape, a bull clip, a nail, and the muscle wire - and it actually worked.


The next prototype was much nicer in materials and hardware (although we were still limited in what we had to work with. We quickly drew up some pieces in Illustrator and went down to the laser cutter to fabricate them. Emanuel, the Professor whom runs the fabrication equipment, was incredibly nice in helping us out and had a lot of interesting stories to tell us. It was both Josh and I's first experience with the laser cutter and we started with lexan - which Patrick tells me is extremely toxic and that I've probably cut 5 years or more off of my life in doing so. Awesome!

The idea here is a simple lever system in order to exaggerate the movement of the muscle wire - as it only actually shrinks about 4% of its length. The top-jaw and the stem are fixed in place and the bottom jaw is the only component which moves.


Here you see a detail of the construction of the fulcrum. We were limited in the hardware that we had to work with, so the bolt is obviously far too long for the overall width of the piece. You can also see the simple system for holding the top jaw in stasis - the top screw and piece of piano wire. Basically, a piece of piano wire ties in at two points, on the stem and on the top-jaw.


Here is a better view of how the muscle wire is tied to the apparatus. It is attached by screw to the stem and runs down to the bottom-jaw and is fixed as close to the fulcrum as possible in order to achieve maximum amplification of the 4% movement.


We worked out a couple of kinks in the design and then drew up the final pieces in illustrator to be laser cut. Here are the drawings.



And, just like that, we have all of these precisely cut pieces of acrylic ready to be assembled.


Josh and I took a quick walk to "Pizza Corner" and grabbed some donairs. They were delicious and I recommend anyone going to Halifax should get a donair from the King of Donairs (they also have really good and HUGE pizza). Here is Josh, happy from the donair.


Part of the final piece. We were able to get some better fitting hardware.

We ended up making 4 new pieces. Here are 3 of them as well as the start of the "hoods" or heads of the Fly Traps, in which Amanda Yakiwchuk devised. We didn't have much time to really develop the head and I think Amanda did an awesome job with them. They are constructed from silver conductive fabric.


Here are Josh and Amanda discussing something. Josh seems to be demonstrating the form and action of the Fly Trap.


This next image is the "tongue" of the Fly Trap. It is a piece of copper conductive fabric with LED's running around the perimeter - a continuation of the piece that Christine Macy started to play with earlier in the workshop. The way that this works is that one leg of the LED (anode or cathode) is taped to one piece of fabric with conductive fabric tape. That piece of fabric is then affixed to the acrylic tongue, which insulates the two pieces of fabric from each other. Another piece of conductive fabric is the affixed to the opposite side of the tongue and the other leg of the LED is the taped to that side. The conductive fabric is then able to distribute a charge from a single source to all LED's.


Here is Amanda assembling the tongues.


And, finally, an image of the final piece integrated (physically only...) into the installation. It is kind of unfortunate, but without the help of the software and wiring experts we were unable to get our piece to work within the context of the installation. But we do have video of the Fly Trap in action, just below. Even though we didn't have it completely integrated it was still an amazing experience. It was pretty interesting being thrown into a body of work that I was very unfamiliar with and to still be able to create and produce an object that actually worked.



Here is the video demonstration of the Fly Trap. Amanda is holding the Fly Trap and Josh is applying the electrical current in short pulses to the muscle wire. With the correct power applied and the right duration of application, the muscle wire can last about 1,000,000 cycles.

1 comment:

Josh said...

Great narrative Evan, i don't think i could have told the story any better. It was definitely an exciting experience. And even though our Fly Traps were never given life, I think we learned a lot and met some awesome people, thats whats important, eh?

And even with the limited supplies, they did have great facilities at Dalhousie, and there were a few awesome things,like the conductive fabric and fabric tape, the Nitonol, those screws with the weird heads and the barely-out-of-the-box laser cutter. Oh and i did get reimbursed for the materials, so it all worked out. If there was only a Canadian Tire in Chicago.

Oh, and just so that anyone reads this knows, Evan and Amanda were amazing, what we accomplished in 2 1/2 days, from learning the hardware, brainstorming an idea, adapting to everyones personality, prototyping, re-prototyping, and assembling the system, for it to turn out as beautiful as it did, Evan and Amanda did a great job and we had a time a great time doing it.