Inspiration for materials

I found an interesting video about memory wire/muscle wire, which could be an alternative material in our jewellery collection (2-3 jewellery pieces). One of the pieces could use this as a trigger for interaction. It can take a shape based on if the person wearing it is experiencing a type of emotion or not.

"[...] flex and contract when a specific amount of heat or current is applied to it. If you are asking yourself “What sorcery is this?!” We assure you, this isn’t magic, it’s just simple science thanks to shape memory and a change between the wires weaker, low temperature form (martensitic) and its stronger, high temperature form (austenite). When the Muscle Wire® is in its martensitic form, it can be formed and bent into different shapes. However, when an electrical current of ~1.5A is applied to the wire, or is heated to ~100C it reverts to austenite form and recovers its previous shape with great force. Additionally, you can anneal at ~500C (use an industrial furnace or simply a lighter) it to whatever shape you would want, next once that current or heat is applied it will return to that new shape."

https://www.sparkfun.com/products/11900

Otherwise showing a persons mood or feelings can be expressed by light. It can be a more ambient way of expressing emotions by simply using a pulsing light that changes color depending of felt emotion or state of happiness for example.