# Gas that expands and contracts QUICKLY?

1. Oct 11, 2014

### JayArpeggios

So I am trying to figure out a way that I can have a very small flexible chamber that would have a gas or something else in it. The gas needs to be able to compress or expand quickly, the point being that the chamber has more pressure or less pressure on demand.

Any help or direction would be very helpful, since I'm a bit lost.

2. Oct 11, 2014

### phinds

By what mechanism do you intend to coerce the gas into compressing or expanding? I'm assuming that your question implies that it is the GAS that causes the expansion/contraction of the chamber so I'm asking what you plan to DO to the gas to get it to do that?

3. Oct 11, 2014

### FactChecker

For any gas the equation relating pressure, volume, and temperature is the same (Boyle's Law). So no gas will be noticeably different from others (unless it explodes :) )

4. Oct 11, 2014

### JayArpeggios

Well I am not set on using gas I am just trying to solve this in one way or another. What I need is a small chamber to be either of these two states: 1) flexible, or 2) rigid. AND be able to switch states quickly. The full mechanism to achieve this needs to be very small. Perhaps electroactive polymers? I don't know much about them.

5. Oct 11, 2014

Staff Emeritus
Do you need to switch quickly in both directions? If only one, you may be able to fill a gap with a non-Newtonian fluid with the right properties.

6. Oct 11, 2014

### phinds

This is what I was trying to get him to THINK about in post #2, rather than just pointing it out to him.

7. Oct 12, 2014

### FactChecker

I like to assume this is a conversation between people with common interests, rather than immediately adopting a teacher-student relationship.

8. Oct 12, 2014

### Staff: Mentor

As stated, a
balloon that you squeeze in your hand fits your description. If that's not what you mean, you must be more specific in your question.

9. Oct 12, 2014

### phinds

I agree completely on the goal, but not on the method. Getting people to think should not be relegated to a purely teacher/student relationship. I don't think of myself as a teacher in these cases, but more of a friendly helper. Also, admittedly, I DO have a preference that people do as much thinking on their own as possible and I strenuously avoid spoon-feeding answers because doing so is, to me boring ... it just becomes about showing that I know more than they do and that's pretty pointless because damn near everybody here knows more than I do.