The artwork is kind of primitive. Gallium is a pretty good idea. In the early days of transistor development, it was used quite a bit. It still is in LEDs (those little red lights that are miniature light bulbs. You should look it up to see what it looks like and what it does to things like Aluminum Pop cans. Those properties alone will be enough to spark your imagination. The problem is going to be drawing your character. Subtle feelings like sadness do not look like they lend themselves to sadness. Even a simple thing like making her pretty/not pretty is a problem.