What can be used as a "motor" of a very small size (less than 1 cm in thickness)?

Question

Do it yourself

The essence of the question is as follows, you need something (engine, pneumatics, hydraulics, etc.) that can, say, move a piston by, say, 5 mm, while the "propulsor" itself should be no more than 1 cm in size, and preferably less. As a less realistic option, I imagined tubes with a magnet and an electromagnet around the tube to move the magnet inside. Maybe there are some other options?

Answer 1

electric motors can be very small, for example, I have a motor from a Canon A620 camera lens that was responsible for the zoom - it is 8 mm thick. The vibration motor of a mobile phone is even smaller. The question is whether he has enough strength to move your piston (how much effort is needed).
on ali you can buy a micromotor assembly with a gearbox and a long shaft with a thread just 1 cm thick www.aliexpress.com/item/N20-screw-gear-motor-micro...
write in the search for motor gear micro and choose, there are options and less

Answer 2

and mechanical elements with a small battery are not considered? like in hours?
Expand the task more widely, why do you need it?

Answer 3

Have you considered piezoceramics?