Looking for a metal or non-metal material

I am looking for a material that can meet the following requirements:

1. It is a strong material (for example it will change its shape only when you press it hard).

1. It has no harm to the body of human beings.

2. It can change its shape relatively quick after applying outside force (say pressing)

1. It will restore its original shape relatively slow after removing the outside force, say a few seconds, or a few tens of seconds. (must be slower than ordinary sponge and rubber back to their original shape).

Requirement 5 is actually optional.

1. Air can go though it (like a gauze), while the dust can be blocked.

Could anybody please provide some advice?

Thank you very much!