Suggestions on making a bubbly-jelly-like interactive substance

I understand the thread title is not much to go over, what I want to make is a membrane like substance that something can go through, and the inside is jelly-like. So whatever enters slows down.
Imagine a micro human entering a cell membrane with some velocity, and it slows down inside. If the velocity is too great, the cell will burst and this needs to be shown too, the cell extending from one side and bursting. If the velocity is too little, the micro human may bounce off the surface.