As I first looked into the muscle fiber which had quite an interessting cross-section it seemed to be a tube which was filled with smaller tubes and those tubes where filled with even smaller ones.  I thought this could be useful for a solid structure which at the same time could transport liquids and other things. For example in a building to transport the drinking- and the sewerage water, maybe also for electricity and other signal cables. With this System it would not be necessary to built a separate tunnel for all this things and at the same time you would have a stable construction for your building.

A quick sketch how the cross-selection of these "tubes" could look like.

Then I started looking at the function of the muscle its self, which I find quite interesting. With such a simple movement of the muscle (open and close) the entire human body can be controlled. So I started trying to imitate this simple "open and close" movement and was positiv that I would find a good area of application.

 

Here I was thinking about the "Sarkomer" of the muscle, it's the part which pulls itself together in the muscle. I was trying to find a function for it.

Then while tying my shoes in the morning a found a really cool function for this mechanism. I thought of a shoe covered in muscles which would tie itself as soon as you slip your foot into it. Obviously I could not use real muscles, but I would have to find something with similar properties.

My first idea of the shoe covered with muscles.

After quite a bit of research I found a metal called shape memory alloy, also known as Nitinol. It is a nickel/titan alloy which can memories a given shape.

The two obvious shapes were the spring and the zig zag shape. If you pull these shapes apart you can warm them up (best with electricity) and they will move back to there memorized shape and at the same time pull two points together. So perfect for my shoe.