Update: Added schematic for the vacuum system
Code word were: CHEAP!
Cheapest RC servos I could get, Cheapest Arduino, almost. Straws from mc donalds, icecream sticks, rubber bands, Lots of scrapped stuff just waiting to be used in the workshop. Solenoids in the valves were from old tapedrives, and the valves them selfs were from old bicycle tubes. Vacuum and pressure comes from an old aquarium pump, reshaped to make vacuum too.
The dark disk is a sun shade, had to add that before filming outside, othervise color detection made too many mistakes.
"Exploded view" of lower arm: