Me and my friends are trying to build a linear actuator matrix. It's supposed to be a grid of pins that go up and down at reasonably fast speed (more than 1cm/s, the faster the better). Problem is, these things cost money and we haven't found something cheap enough. We have about $300 to spare, and would like to have ideally 1000 of them, but we can make do with about 300 (again, the more the better, and even better if we save some money).
We haven't found a cheap enough linear actuator that is small enough for our needs (2mm to 10mm diameter, the closer to 2mm the better) and we would like your help.
EDIT: To all your questions:
I'm building a tactile electronic display (which will look like a bed of nails) that people are supposed to touch.
I'm not sure how force the pins should withstand, but they are not going to be pushed, only touched by blind people, I presume it's less than 100N but I also think it is way less, I just don't have an accurate number.
As for the length I need the actuator to travel, about 5 to 15 millimeters.
To the guy who asked if the pins need to be either up or down or at different positions: There is a small preference towards intermediate positions (no specific number of positions required) but if the price doesn't allow it, we'll make do with up-down.