I still need to track down recent papers.
Otherlab has some nice videos on youtube: one, (a 15 minute talk), three, four (see Siddharth at 31s into the video).
IRobot inflatable robot, article
Random inflatable robots one, two.
Toys/art one, two, three, human inside?, five, six, seven, eight, nine, ten.
This page has a nice collection of pointers to inflatable robots.
Here is a nice review:
A hand design
Another hand design
Printable inflatable robots
Jamming robots one, two.