There are millions of way you could improve this, I had a lot of fun making it, and I think it would make an excellent gift for someone special.
This is was my first time using an Arduino or wiring anything. Unfortunately, all the materials used were not mine so I couldn't make it permanent. However, I though it was an effective, albeit expensive, way to make a bear react to a belly squeeze. It would also make an adorable gift if you had a little extra money and could maybe add sound.
What you'll need.
-Arduino (If this was permanent I would suggest something other than the MEGA)
-thread and needle
-hammer and nail
-something clear and plastic
-batteries or power source
I would suggest something with a belly to squeeze. The whole point is that its react well to the natural belly squeeze. It also has to be big enough to house the flex sensors, Arduino, and batteries. I would just make sure its big enough that an Altoid can could fit inside it with enough room to not be too noticeable.
Step 2: Prep your Bear.
Begin by cutting his along the side of the bears belly and removing some of the stuffing. I only took out as much as I needed to work. Next, I cut hole in the front of his chest with a pair of scissor and sewed up the edges to prevent it coming apart.
Step 3: Add his little plastic window
This is the part where you add his little plastic window. I used the bag of a paperclip package, but this is a part where you can get creative, perhaps a different color or shape. Once I cut it out, took a hammer and a nail and went around the edge puncturing little holes so it could be sewn into the bear.