There are some sex toys that use other ways to provide mechanical stimulation. These usually depend on a motor that makes the sex toy continually change its shape which provides a sort of rotational movement or makes it move back and forth.
The back and forth movements are sometimes powered by an air pump rather than a motor. The movements have been used to create, for example, mechanical licking tongues, vibrators that 'penetrate' the vagina and mouth simulators to give a man a 'blow job'.
On a bigger scale and much more expensive, there are 'sex machines' that incorporate thrusting and vibrating dildos.