How to handle extremely high pressures: go soft:
https://www.newscientist.com/articl...-survived-the-pressure-in-the-mariana-trench/
https://www.newscientist.com/articl...-survived-the-pressure-in-the-mariana-trench/
The submersible robot looks a bit a manta ray and is 22 centimetres long and 28 centimetres in wingspan. It is made of silicon rubber with electronic components spread throughout the body and connected by wires, rather than mounted on a circuit board like most submersibles.