Thursday, March 8, 2012

Origami Electric LED Fortune Teller v1.0

I had a free morning and limited supplies, but wanted to make an eTextile project. This project takes household materials - paper, tin foil, scotch tape, a few LEDs, a resistor and a 9V battery - and creates an interactive LED circuit that changes the color and LEDs that are lit when the fortune teller (also called cutie-catcher) is moved. Creating a flat circuit on a folded structure is very interesting because there are freedoms and constraints each time there is a fold or the edge of the paper. I took advantage of this fact when designing the circuit layout. While each trace is flat, they span three dimensions by changing sides of the paper and moving to a different section where folds meet.

Connecting the power was done with two alligator clips. A 500-ohm resistor was wired in series with the fortune teller circuit to reduce the current to the LEDs to a reasonable range. The blinking that occurs when two LEDs are lit (visible in the video above) is due to the split of current between the two LEDs. To avoid this problem, a resistor should be wired individually to each LED (so in parallel with each other when all the switches are closed). I want to keep the design as flat as possible in order to maintain the paper quality of origami, so I will use drawn-on graphite resistors made with a soft graphite pencil to version 2. This should solve the blinking problem, and allow for full functionality. 

The first step was to fold a normal fortune teller. Then contacts needed to be added to each of the inside flaps, so that when the two surfaces come into contact, an electrical connection is made.The LEDs are tucked into the corners and taped into place.

One center flap unfolded:

 Unfolded from the center:

Unfolded and flipped over:

Power connections on the base:

Friday, February 24, 2012

Hexapod Rudimentary Sketch

Here is a quick mock-up of the design for the hexapod. The red indicates where muscle wire will be attached. It still needs much work and more aesthetics. In any case this is just to give you an idea.

Thursday, February 23, 2012

Revival - New Project Ideas

Hello again. I am back from a year in France and have decided to revive my project blog. I have my mind set on two new projects. One is a small robotic hexapod that uses muscle wire, and the other is a large scale art project that will turn the area outside Georgia Tech's student center into a large koi pond.

How am I going to do these? Here are some details on each:


The hexapod I will be creating will be small and relatively silent. The idea of using muscle wire comes from wanting a low-cost solution. Additional advantages are that it will be completely silent, as opposed to the far more common servo models. My Perspective and Robotics class, taught by Dr. Mike Stilman was what first sparked my real desire to build a hexapod for myself. This project would allow me to explore and model various motions and gaits. The hexapod structure is already well known for being a simple platform to start with as it is intrinsically stable. As I began to research hexapod designs, however, I discovered that any prefabricated designs were going to cost me upwards of $500 at the cheapest. I resolved, therefore, to build my own.

My hexapod prototype will be controlled with an Arduino Mini 5V microcontroller. The muscle wires themselves will be powered through a 9V battery (the Arduino cannot provide enough current itself). For the body of the hexapod, I am planning to use laser-cut polycarbonate. Each leg will have two degrees of freedom. This will be enough to allow forward, reverse, and turning motions. Using two instead of three degrees of freedom on each leg does remove the ability to walk sideways. Right now I am attempting to develop a body and leg design that could allow sideways motion through sliding and shifting of the center of mass of the robot.

Koi Pond

I have long been interested in large artwork, as shown by my footprint stencil project. I did attempt initial work towards a large koi pond, but found that the clear plastic I was using was impossible to see and too flimsy to really work with. In my new attempt, I am going even bigger than before and have ordered a 10' wide and 25' long sheet of black .006" thick Polyethylene film from McMaster-Carr. I plan to place three large fish done in spray chalk around the student center by the end of this semester. For this project I will need to document the square footage to spray chalk ratio for the recipe I choose to use.

As I work on designs towards these two projects, I will post the progress here. As soon as parts arrive, I should be able to get going!