what type of actuator is used in this video?

A. It looks like a short displacement servo positioning controller, raising and lowering the right side for load and actuation. You can check what's available by google
http://www.google.com/search?hl=en&biw=1144&bih=699&q=small+distance+servo+positioning+controller&aq=f&aqi=&aql=&oq=

hth :)

Q. When she hears the key in the door, sometimes she runs to hide under the bed, too. We adopter her from a shelter, she's 11 years old and her information says she doesn't like kids or female cats. She loves both of us, and as soon as we peek under the bed and she sees who is home, she'll come right out (usually). Is she just anticipating somebody she doesn't like coming home?

A. Just like people, sometimes cats personalities change a bit as they get older. At 9 this cat is late middle aged.

How long ago was it you took the cat to the vet, was it months or years (your question doesn't) say. If it was more than 6 mths ago then I would take him back for a full check up. A change in personaility can have physical cause.

Has anything changed in your home - are there any new additions, or have people left? Any change can cause depression in cats.

If all checks out the here's what to do:
*. Don't give up on the play - try different types of toys - often you just need to find the right one. There is even an app for iPad called Catch the Mouse - my old cat loves it
* make sure kitty has access to scratching posts, places it can climb up high, baskets to hide in.
*. Without going overboard, make some games with kitty's food - a bit like the Konk toys they have for dogs
*. Is he an inside cat? If so - and I appreciate there is some expense and effort involved here - any chance you can build an outdoor enclosure?
*. Everyday spend some time brushing kitty, then finish up by wiping him with a clean damp cloth. He will love it and it is good for his health.

Most importantly don't give up on him. He may not follow you around anymore - but he's not a kitten anymore. Of course he still loves you - he just shows it in a different way. For my money old cats are the best cats!