I took mylar and ironed the edges to seal them into a pocket or bag shape, leaving a gap where a straw could be inserted to inflate it.
Air leaks slowly out the opening, but it's very firm for short periods of time. Maybe something like this could be useful for cushioning/suspension?
Meta-note: Did you notice that the video above gets pixelated as soon as there's motion? I think it's because the changes in the reflective surface of the mylar are hard to compress. Here's where I learned about this phenomenon.
I tried tapping on the inflatable harder, and it tore a hole at the ironed seam!
I wondered if big inflatable spaces were the cause of the issue. Perhaps with smaller air pocket, the forces on the seams would be smaller? So I tried to create a bag with many little pockets:
I found that marking where I was going to create seams with permanent marker was helpful for both planning and documentation purposes.
The result: The seams still came apart!
From all of the explorations so far, it seemed like using mylar and an iron could only get me so far in terms of how much force this basic soft robot could exert -- it seemed pretty useless. I tried hard to come up with a potential useful application, and came upon this one:
When the inflatable is inflated, it moves some objects. That's kind of useful, right?
On another note, I realized that having weak seals is not an inherent drawback of inflatables, because mylar balloons have much stronger seals that don't leak.
I tried adding my own seals onto a mylar balloon to see what would happen. Long story short:
I ironed the hole to reseal it. It worked… until it didn't again. After a few iterations, I ironed it and it the seal didn't immediately come apart:
But when I pushed on a balloon, air still trickled out. I found out that my amateur seams were still leaking out of numerous tiny holes. I'm not sure if there's any way to prevent this, other than by using a different kind of sealing technology, or by never applying much force to the inflatable.
Here's the "finished" inflatable. It's not much, but it definitely looks different than the original heart shape of the balloon. I think it kind of looks like a red blood cell.
All in all, I didn't find too much utility (yet) in the inflatables I experimented with.
However, as I cleaned up everything, I found an important one: inflatables can be incredibly compact. All 5 of my mylar attempts (some of them not documented above because there were so many) together could be folded into a shape that easily fit in my pocket.
