Create a Necklace With a Lovely Hidden Message

The concept of this idea is supported by creating an object that hides messages, that are revealed by the act of time and curiosity. I believe artifacts should be mediums for playful and memorable experiences, where its attributes don’t scream for attention.

The object makes use of the iconic act of ‘hugging’ as a symbol of friendship, connection, bond and support, and also as the switch for the necklace to change state and shape, and to reveal a new message.

Materials:

• Sewable Snaps - 5mm Diameter
• Woven Conductive Fabric
• Fabric
• Heat-N-Bond Ultrahold
• Stainless Medium Conductive Thread
• 9V Battery
• Untrained Flexinol 0.012”
• Trained Flexinol 0.08” (from )
• Red paper
• Rubber tubes of different diameters (I got it from Canal Rubber in NY)
• A small piece of wood (the wood will be burned, so it can be any scrap)
• Small nails

The necklace went through several tests and experiments. First, I decided to use trained flexinol around a cloth bag, which it’s contracted when current passes through the wire, taking the form of a heart-shaped wooden piece that is located in the center of the collar.

Continuing with the experiments with trained flexinol, I tried having a cleaner shape by placing the wire inside a plastic rod, whose volume contains living hinges. The idea was that the rod could take the shape of a heart when the wire was activated by heat. Unfortunately, the flexinol coils while is contracting, making the rod also follow this behavior, and impossible for it to take the shape of the heart.

Many tests were also done with untrained flexinol. As in the previous experiment, I wanted to have a pure and clean shape at the start, and then changing the shape by activating the wire with heat. Many interesting learnings resulted from this experiment. I used a 0.012 "diameter flexinol wire that you can get here, which must be activated with 1.5Amps, a considerable amount of current. The wire must be programmed to take the desired shape. To program it you should first draw the desired shape on a piece of wood, and put nails following the drawn line.

Attach the flexinol to the nails as tighter as possible. We want to have a clean and continuous line when the flexinol is programmed.

Pass a lighter through the cable. Avoid leaving the lighter in one spot for much time to prevent it to burn.

Put the flexinol into container full of cold water. Remove it from the wood jig and that’s it! The flexinol is now programmed.

To test the programmed flexinol, simply pass current (I tested a 5V, 7.5 and 9V, with 1.5Amps. The best result was with 9V and 1.5A) or quickly pass the lighter through. Avoid leaving the lighter for much time if you don’t want the flexinol to get programed again.

Create the necklace by following this scheme.

I use conductive fabric, which I bond to a strap of fabric using (heat-bond – see this tutorial in here)

Sew metal snaps to the fabric (follow the circuit scheme)

Create a pocket using a fabric strap to hold the 9V battery

Solder the sewable snaps to 2 wires. These are going to be our connectors and also the chain.

Create the switch by following the circuit scheme. I used a piece of foam with a hole in order to separate the two conductive surfaces, and also to create a touch feedback when contact happens.

Create a heart shape in paper following this tutorial

Attach the flexinol wire inside of the paper heart. When the wire contracts, the heart changes from a flat-five sided shape to a heart volume.