I need two state linear actuator. You can have a look at the picture to understand what I mean.
Don't care about the hand !
I need to electrically move the things like this squares up and down. Bidirectional linear actuators are needed. What is the cheapest and tiniest actuator (or sth else) that I can use to move this squares up and down. There are just two states ('up','down'). Don't care how much higher a square rises, when it is up.