Here is a 3D printable inflatable actuator dipped in silicone to make it airtight. This could be an alternative to casting for making soft actuators.
There are some annoying things about designing sensors and actuators, and sharing those designs. One big problem is getting everyone on a project set up with the right software to create, share and modify designs. When I have a mac and you have a pc, and the software costs a lot and files from new versions are incompatible with old ones, everything gets stuck and we have not even begun talking about how the design works.
In that spirit, here is our parametric designer for the telescoping cone actuators. In 2015 it works in Safari, but you have to enable WebGL. Slide some sliders, get a stl file, and your browser is doing all the work except printing it and dipping it in silicone. If you print it, you’ll have to chip out the support material to separate the cones. Thanks to Chris Kimmer for the test prints.