Using Silicone to Keep Wearable Components SAFE

We have all spilled water or coffee before.. but what if it goes onto our beloved wearable components? It would ruin or fry our components.

So today, I'm introducing a new way of keeping our wearable components waterproof and dust-proof!

Lets take the precautionary step to be safe!

1. How to: Keep your micro controller (eg. Arduino, Lilypad) waterproof, dust proof and protected!

2. How to: Protect conductive thread flexibly - and it from slicing and tearing through foam (Sound insulating foam)

Part of the process of finding and creating my own Instructable was to see what was already out there and through this research, I got INSPIRED!.

Huge credits to smalltortoise for exploring protection of an arduino board with Instamorph in their instructable - https://www.instructables.com/id/Protect-Your-Ardui...

However, personally, I'm not convinced by this idea because removing instamorph for any reasons from the components might cause them to break parts off accidentally. It's too hard to have flexibility for a wearable.

1. How to: Keep your micro controller (eg. Arduino, Lilypad) waterproof, dust proof and protected!

- Foam Core

- X-acto Knife

- Cutting Mat

- Ruler

- Hot Glue (About two sticks)

- Tape

- Oomoo's Dragon Skin FX Pro Silicone Mix

- Plastic party cups (minimum 6)

- Sharpie (Black, just to label)

Terminology
* Core : The part of your product

* House : The part that holds the silicone like a bowl

Steps:

1. Find the dimensions of the your micro controller (Lilypad = 3 x 3.1 x 0.3 in)

2. Draw the top view of it onto foam core board (Give it about +0.5in tolerance space)

That would mean drawing a circle with a diameter of 3.5 (Since 3 + 0.5 = 3.5in)

* You can use any material you want to create the part that you want to mold. I've chosen foam core board because it was accessible to me. AS LONG as it is the right thickness or stacks up to the right thickness. In this case, 0.3 + tolerance space, 0.25

Decided Final Thickness = 0.55

3. Cut it out with an X-Acto knife and glue/stack them if the thickness was not what you wanted.

*Sometimes laser cutting a material out would give you better finishes :)

Terminology
* Core : The part of your product

* House : The part that holds the silicone like a bowl

Use foam core board to house your core

- Create the base square that's slightly bigger than your core, give it about 0.75 inch from all edges

- Cut 1 inch wide strips of foam core and glue them to the base with hot glue

*Be sure to seal off all edges very carefully because any leakage would cause the silicone to leak out

- Create another strip (no dimensions really), and hot glue it to the top of the core. Then tape it down to the box so that the core sits on the house, elevated from the base square.

To be honest, you can actually use any rubber or silicone compound to form your mould/house.

It just has to be waterproof and flexible enough to work with the house of your object.

Here I'm using: Oomoo's Dragon Skin FX-PRO Silicone, because it's extremely safe with the skin. It's medical grade safe, waterproof and strong. You can also choose the amount of turgidity you want when buying it.

Advantages of using silicone:

- Safe to use, will not cause allergy

- Least reactive material to any substances but itself

- Silicone can stick very well, only to silicone - (Think Glue)

- You can add pigments to change the colour of it (Specific ones. Silicone's natural transparent colour gives you options in choosing your colour choices)

http://www.smooth-on.com/Silicone-Rubber-an/c2_111...

For Dragon Skin FX Pro, the instructions in the box says that it has 45 mins cure time and a pot life of about 10mins.

Terminology:

*Pot life : How long you get to stir and mix the components before they start to harden and kick off, you want to make sure you have plenty of time to pour your mix into the mold before it hardens.

*Cure time : Time taken for the silicone to fully set

For Dragon Skin FX Pro, this one has a mix ratio of 1:1 in volume. (Some may require mass and a weight to do that)

1. Pour them into seperate cups and mix them thoroughly individually

2. Pour them together into a "mix" cup

3. Stir the "Mix" cup well

Most rubber compound require patience when pouring. Because I'm not using a pressure chamber, the need to pour it extremely carefully and correctly is very important.

It is crucial to understand that when you stir mixtures together, you essentially stir air into the mixture, causing bubbles. With a pressure pot/chamber, you can remove these bubbles so that it won't affect the smoothness or surface of your mold.

But if you don't have a pressure chamber like I do, pouring it carefully and correctly will reduce the amount of bubbles.

1. Pour the mixture into the mold at a very slow rate

2. You want to pour very flat and slow

3. By pouring it flat, you stretch the mixture and release bubbles by causing them to break under the stretch

4. Pour it slowly and let it flow into the entire mold

5. It's okay if it starts to overflow by a little, but if it overflows by too much, remove some of the liquid before it sets

Now, be patient and let it sit for 45 mins

After it has set (not sticky or icky or gooey), you have to remove the house and the core from the silicone.

Because it's a rubber compound, it will most likely adhere pretty strongly. You might have to break your mold to obtain the negative part.

Just rip it apart :)

Repeat the same process to get the top part of the casing. This time, you can reduce the 1 inch strips, to about 0.75 inch.

The benefit of using silicone to house your components

To keep the house secure

Silicone has a tendency to want to be flat against itself

1. If you want a non-permanent joint

- Sew and thread through the edges of the silicone tight so that it sits flat against each other. It won't be super tight, but because the silicone wants to sit flat against itself, you will get a watertight seal naturally (don't expect it to work if you're adding extra force.

2. If you want a semi-permanent joint

- You can paint/spread some liquid silicone on the edges of the house so that the top and the bottom can stick together entirely.

- This ensures that you can move the house around without worrying about the watertight seal

- And if you ever want to open it, you can slice it with an X-acto knife

To insert other parts and make it compatible

- Poke needle sized holes and push anything through to wrap the part really tightly around the silicone

- It's material characteristics allow for tight seals around a surface

- You can push part two of this instructable through it to make an entire circuit waterproof

Note, because silicone only adheres to itself, glue of any sort will not work to stick two silicone parts together. You have to use silicone to stick silicone

2. How to: Protect conductive thread flexibly - and it from slicing and tearing through foam (Sound insulating foam)

- Cut the house from foam core board using an x-acto knife

- Glue it water tight with hot glue (No leaks!)

- Use a needle to puncture two holes on each end of the house (Make sure it's at the same height)

1. Insert your conductive thread

2. Tape the ends down or hot glue it so the thread is tight

Same as the steps from above, mix and pour the mold

After 45 mins of set time, again see if it's icky or gooey. If it isn't, you're all good!
Remove it slowly from its house

- Waterproof

- Dust-proof

- No need to worry about oxidation

- FLEXIBLE ! (Much more flexible than using wire that are insulated with plastic)

- You can choose how much casing you want for your conductive thread

- You can brush on silicone coat after coat if you want it really thin

(Brush on, let it dry a bit, then brush on more until desired thickness - But remember, you do want to give it some thickness to really protect it!)

- You can create a super thick house for it

- You can change it's colour

- It's safe for the skin, non allergic, medical grade safe.

Linking back to part 1: You can poke a hole in part one and press fit these insulated conductive thread into part one so that it creates a tight seal between the conductive thread's silicone and the house's silicone.