The main part of the actuator is a silicone bladder made from 8 mm silicone hose. The hose is then encased in the aramid braided sleeve ( aramid cable sleeve ) and screwed into hose connectors. The length of the hose should be chosen to match the application , remembering that the shortening of the actuator is around 30 %.
Here is the cross section of the single "muscle"
The bladders are installed between two aluminum blocks acting as the mounting elements and the conduit for the hydraulic fluid . The technical drawings of the blocks can be found in the files section of the project. If one needs more force exerted by the actuator the blocks can be extended and equipped with more "muscle bladders" connected in parallel .
As you can see , there are two types of mounting blocks . One is designed to be fitted with a 4mm push-in connector , the other should be fitted with a Schrader Valve . The 4mm connectors would be connected to the pump , while the Schrader Valve is needed for filling the system and bleeding the air out of it.
When all the parts are ready , all the connectors should be installed into the blocks first and sealed along the thread using either a dedicated sealant or a bit of epoxy . Then the hoses with the sleeves should be screwed into the connectors. The finished actuator should look like this :