Particle jamming is amazing. Take a balloon, fill it with some granular media like uncooked rice or beans and suck the air out with a vacuum. The balloon stiffens and holds its shape. The stiffness of the bladder is easy to manipulate and quickly changes from a completely floppy state to something as hard as a rock. The higher the vacuum, the stiffer the jamming bladder becomes. Of course, the granular media that you put inside the bladder also affects its performance. Fill a balloon with jelly and it’ll remain relatively malleable even with a high pressure vacuum. On the other hand, if it’s filled with glass marbles, you’ll won’t be able to shift its shape whatsoever once a high vacuum is pulled. That’s the magic of particle jamming.