Changing temperature powers sensors in hard-to-reach places

For those getting parse errors when reading the title:

> Changes in temperature can be used to power sensors located in hard-to-reach places

Enocean has been doing this for years, http://www.enocean.com/en/edk350/

The UW research is actually using a device from enocean, it seems.

Bill of materials

Atoms Bellows: We purchased it as an Atmos Clock's spare part. You can buy it from eBay

EnOcean ECO 200 Linear motion harvester: Description | Order here>

3D-printed parts You can download the design files from here.

MSP 430 Launch Pad for demo.

Segmented E-ink Display for demo.

5 x 74HC595 for driving the E-ink display.

RFM DR3000 Wireless Module

I wonder if something similar could be done with the volume expanding wax used in the hydraulic cylinders of green house vents?