Hi,
This is a slightly odd question, and I think this is probably the right place for it.
As I mentioned previously, I'm hosting a failed selfie exhibition and will be doing food and drink to match. One thing that I thought would be fun to do, however, was encase a functioning telephone in a set jelly/jell-O and have people call it. It would be set on vibrate, obviously 
Anyway, this is not something I've done before, and the logistics are a bit interesting:
- How can I stop the jelly destroying the electronics? Would a phone survive being vac-sealed?
- Which proportion of gelatin to water do I need for structural stability, but maximum wobble?
- Would a larger jelly wobble more satisfyingly?
- Is a phone's vibrate setting even strong enough to wobble jelly?
- Fully transparent or coloured?
I don't intend to serve this as food, so food safety and flavour are not an issue.
All suggestions welcome.