LIQUID-GEL-LIQUID PROBLEM

dear fab 4440, perhaps you could use a polymer that when exposed to the salt present in the ear would cut and thus liquify, like many of todays shampoos work. (believe it or not it is salt from our perspiration that cuts the polymers in the shampoos that then help them "suds up.") Check out the labels of some shampoos and then find a consulting chemist.

Just a thought.

In keeping with my long standing "protect the customer" principle, you are aware of the FDA requirements and testing and approval protocalls for materials contacting humans tissues???

milo

I can understand what you are trying to accomplish but, I can't think of a single liquid that would gel on temperature rise and re-liquefy on temperature drop that is also suitable for your intent. The only thing that crossed my mind would be to mould a standard "plug" from closed cell silicone foam having a density soft enough to be comfortable to the wearer.

BTW, are you meaning "universal" as 'one size fits all' or as in multiple users of a single device?

Good luck with your project.

FKIA

Thanks for your advice i have stipulated "universal" for the reason of fit to size.This effectively cuts out the middle man who performs the task of taking a mould and then creating the silicon ear piece.

FAB4440

Fab4440

I think I can come close. I sorry I don't know the name of the material, but I think it just might push you in the right direction to solve your problem.

There is a hand warmer on the market, (look into outdoor stores that sell to hikers, campers, fishermen and hunters). The hand warmer is a liquid in a plastic sack with a metal disk in the liquid. When you bend the disk in the liquid it 'snaps' and then the liquid starts to give off a lot of heat and turns solid. While it's giving off heat, you can sort of shape the plastic sack to fit your hand or pocket.

To get the hand warmer back to liquid, you boil it until you don't see any crystals in the liquid, then you can remove it from the boiling water and allow to cool. You can reuse this hand warmer over and over again.

I was thinking if that liquid in the bag is diluted, then maybe your idea would work if the mix was slightly different.

I suggest you find out what they are using for this hand warmer as you may be able to alter the chemistry just a bit to get what you need.

Or, it may not work at all. Just a suggestion.

I think the hand warmer uses a supersaturated solution of Sodium Acetate, hence once dissolved, any disturbance causes crystallization.

I'm only going on memory for this so I may be wrong.