GOALS:

We decided to use this project to help us test and prepare for the final projects we are currently working on.  The goal was to create a dyed felted fabric that changes color in specific areas and patterns in a more controlled way than our previous experiments.  By using an arduino, an additional power supply,  and circuits that contain a mosvet, resistor  we are able to control specific areas of the fabric using different pins on the arduino. Our hope for the near future and for our final project is to be able use out side data (specifically weather and temperature) to control these changes.

PROCESS:

Knitting

The first step to creating this fabric was to knit a large sample on the knitting machine. This sample was  knit with a light weight cotton yarn (purple) and a heavy wool yarn (white). The differences in the yarn weights allowed for the yarns to variegate creating an interesting striped pattern.

Sewing and Felting:

Before felting the piece lines of steel were sewn into the fabric in a zig zaz pattern. Before sewing the lines were mapped out  with tape as channels on the fabric.

After the sewing was completed the fabric was thrown into the wash to felt.

Dyeing

The next step was dyeing the fabric. Instead of vinegar like we used here we used lemon juice. After some research on natural dyes we determined a different process to use. This process involved first boiling the fabric with a fixer (lemon juice) then rinsing the fabric and letting it soak in the thermochroomic dye overnight. After soaking it was hung in the sun to dry . Dye Process

This process seemed to take much better than the vinegar dye used for the first experiment in dyeing yarns. It also does not smell as pungent and seems more wash-fast.

CHALLENGES:

Heat actuator Water Crystallization SMALL

Water droplets were frozen at -78C for 10-30 minutes, before being imaged under 625x microscope.  Some water droplets were subjected to negative pressure for the freezing process (.5 and .33 atm respectively), and their crystal size compared with 1atm frozen water.  Glycerin and PEG (Poly ethylene glycol) were also frozen.

The point to take away from these images is that the ice crystals (the small, granular, sharp angled shapes) melt, turning into water droplets, followed by water droplets conglomerating into a larger droplet.  The first part of the crystal to melt are the fractal “arms” which extend past the center of the crystal; these are pointed out in a couple images.  The effect of the greater “stickiness” (surface attraction) from the wetted crystals, as well as a bulk amount of liquid outside the focus of the microscope, causes more crystals to move into the focus of the microscope as the melt continues.  The end of the melt process results in many individual domains of mini-water droplets; these then combine to form macroscopic droplets.  The initial size of these droplets is indicative of general crystal size; lower pressure results in smaller crystals.  These smaller crystals are somewhat difficult to image as droplets, as there is greater surface tension and thus reason to form larger droplets quickly.  In general, there were issues with imaging since the ice melted so quickly; using a controlled, sub-zero C environment for the entire microscope set-up and environment would help with this issue, and allow for greater time to find a perfect focus and thus greater possible resolution.  In such a scenario, direct measurements and analysis of the ice crystals could be readily performed, as opposed to the analysis of their post-melt state.

Neither PEG nor Glycerol formed large crystals similar to those of the water.  The glycerol is either very poorly crystalline or amorphous; it seems as though the PEG has an even weaker trend towards crystallinity.

Ice is a readily available material that illustrates many of the principles behind designing solid-liquid heat controlled actuators.

The voiceover and subtitles explains how this works, where a soft rubber pouch is actuated by pressured air. The simplified demonstration below shows this, a syringe of air changing the dimensions of the finger-pouch:

I decided to use a medical syringe as the air pump, examination gloves as the membrane, rubber bands to provide a seal, and soaked cotton balls as the jamming content. I used a bunch of lightweight dental sticks as pickup objects.

So after snipping off the fingers of the glove, I made this:

a surrealistic little finger.

I wanted to test it with unsoaked cotton ball first, as well as a combination of unsoaked cotton ball and ground black pepper.

Finger with Cotton and Pepper

The finger failed to pick up the stick when actuated with air.

I had much more success with water-soaked cotton.

Successful Pickup with Water Soaked Cotton

It also manages to pick two up, albeit a little badly.

Pickup of Two Sticks

I tried fluids with different viscosity, first honey, and then soy milk.

But viscosity changes the effectiveness dramatically, such that I seem to achieve a stronger suction effect, but without a corresponding increase in successful pickups.

Unsuccessful Pickup with Soy Milk

Inspired by the hydro skeletons and muscular hydrostats in nature (e.g. elephant trunk, starfish, octopus arm, etc.), the kinematics are based on the combination of elastic material body actuator and pneumatic pressure feedback system.

[Module and Power Source Feedback Loop]

[Kinetic Study Process Sketches]

[Table of Kinetic types, material and Geometry]

[Mold Fabrication Process]

[Kinetic Study Demonstration Video]
Bend 01

Bend 02

Expand

ThermoInkPresentation_1

Resources:

http://www.youtube.com/watch?v=gDFACj607Dg&feature=related

http://www.youtube.com/watch?v=wckgz5DuivU&feature=related

http://www.youtube.com/watch?v=20z-PHLbdUA&feature=related

http://www.fashioningtech.com/profiles/blogs/designing-dynamic-textiles

http://www.ppg.com/corporate/ideascapes/glass/products/alliance/Pages/pleotint.aspx