Temperature Affected Materials

Sorry, mate - that makes no sense.

"shrink/push"?

Try re-phrasing the question to rectify that, and you may get a sensible answer. Are you thinking about "memory" materials, or just something(s) with non-linear thermal expansion characteristics?

You are right, poorly phrased. Memory materials is proper

Sorry - can't help. But at least the others will know what the subject is.

(Welcome to CR4).

JohnDG isent you an answer and agreed with your commnet on "memory" materials

All materials shrink when cooled and expand when heated.

Why couldn't a simple bimetal strip do this?

(From about 39°F to 32°F, water expands as it cools/freezes. That's why ice floats.)

If you search on "memory metal" on google, you might find what you're looking for. Not too sure if they will meet your temperature requirments though.

There are also bimetal diaphragm switches that have a pronounced "snap" action. I think "Klix-On" uses this principle, and they might have some examples in your desired temperature range.

jip, seems like a memory metal (NiTiNol) might be what you need.

By adjusting the Ni/Ti ratio the material can be adjusted to phase shift at different temperatures.

Try "Memry metals" in the states. They were willing to ship me a sample a few years back

Johnson Matthey show a couple of alloys that activate at near 0°C here.

There is a titanium alloy that will do this, it is called memory metal, but I couldn't tell you where to buy it, sorry!

Xanasax

Depending on what you are trying to do, a rubber bladder filled with plain old H2O will perform that way.