Need name of component, controlled grid of pins

Hello, thanks for looking.
I came here because I was looking for some engineers that might be able to help me move a hobby project forward. I'm a complete novice.
I'm looking for a very small electronic device that moves small pins up and down. The pins would be in a grid within the device, so you could send a signal to make individual pins move.
For reference, it's kind of like the 'Pin Art' toy where you press your hand onto a grid of pins, and the shape of your hand is pressed onto the other side. Also, Hyundai has a very impressive room that has moving blocks forming the walls.
Does anyone know what the part I'm looking for is called? It seems like it has to exist for some other purpose. I'd like it to be as small as possible. Also, I'd like it to have a high number of pins (hundreds), closely packed.
Thanks again, any help is greatly appreciated! I did a simple mockup, the image is below.
Mike

As far as i know there isn't a regular part that has this specific function, i guess if you want it, you should make a custom part. There is however a part that moves an iron pin up and down, its called a coil, or to be more specific, a solenoid. That is essentially an electromagnet that moves an iron pin up and down.
To build this device of yours, you would need a LOT of solenoids and the problem is that if they are too tightly packed that they intefere with one another. Next to the solenoids you would need some drivers, controller hardware and software and last, but not least, interfacing hardware (for the digital interface). I do think this is a very interesting concept and i hope to see more of it! I hope i was of some help to you.

Yours sincerely,
Boi

Hi Boi,

Thank you for sharing your knowledge, that's very helpful. I was searching all over the net for a non-existent device apparently. That saves me some time, but also means I'll have much more work ahead of me if I want to make it happen.
I'm researching solenoids now, hopefully this info will push me in the right direction.
Thanks again, I'll update you if I make any progress.

Mike

Another term for a device that moves this way is "linear actuator".

you could also look into BI-Metalic strips that when a current is passed through them get hot and bend .but
my preferred method would be compressed air, precise drilling of a composite block in the configuration of the needles, each drilling connected to a small hose which is supplied compressed air through a solenoid valve . it means the controlling components are away from the needle array and can be as big as you like

Thank you three for your helpful feedback and ideas.

Sarah, I like your air pressure idea, that seems like it could work! It's not using too many parts, and as you stated, you could squeeze the tubes into a much smaller array than an array containing the solenoids. You wouldn't happen to know if such a component exists? Not the grid of pins, but a device that controls a contained array of electronically controlled solenoid valves. It seems like that would be in existence, possibly for printers.

I'm researching everything you guys are suggesting, glad I came here.

i would be inclined to look for a ready made controller as you are a complete novice. a rolling led dot matrix sign could easily be converted to control solonoids..something like this http://www.bestwant.com/uk/p10-32-96-semi-out-door-led-moving-sign.html

Nice! You're very kind to put your energy into this. I really appreciate it. I think you're giving me a great direction.

Another possibility is _nitinol memory wire_ coils, one around each cylinder. One side of the coil is attached to the platform and the other side to the cylinder. Pass a current through the wire and it tries to straighten, taking the cylinder with it.

* cimar.mae.ufl.edu/CIMAR/pages/thesis/santiago_jr.pdf
* http://letsmakerobots.com/node/23086
* http://www.talkingelectronics.com/projects/Nitinol/Nitinol-1.html

Maybe you should look at Braille printers?
They punch dots on paper instead of spraying ink.
So there might be similarities in function.

Nitinol memory wire is very intriguing. I wonder how it would hold up over time? If it'd eventually lose it's memory of it's relaxed state.
Per- I looked into braille printers, thank you. They seem to all move paper along in a way that it only needs a few pins to punch through. That research led to electroactive polymers, which might work. Exciting stuff!

hi mike

I think the link below will help
the pins move up and down. it allows rapid prototypping
http://www.bnpeters.com/digitally-reconfigurable-mold.html
good luck

sarosh mehta

Sarah has the right answer Well done sarah !! and where can you get this from Sarah ?? A ready made matrix out of toys believe it or not from the " Throw away age no less tarum de darum"

read my article on this

http://www.eeweb.com/blog/mark_harrington/gen...an-pick-up-without-having-to-even-spend-money