Also joining us in the lab this summer was Will, a local high school student. He worked on a pressure sensitive film project to quantify real area of contact changes of samples in the rig. After getting the method down on roughened teflon and PMMA, it was time to start working on ice.  Since he was looking at contact area change with time and normal stress (but zero velocity), we didn't need to use both pistons for his experiment. Working with Mike, they designed and built a special purpose cryostat with a wood frame and this green styrofoam for insulation.

The cryostat fit nicely into the apparatus, allowing it to be pre-chilled with circulating fluid and loaded with the prepared ice sample and forcing blocks. A small slot at the top allowed him to change the chilled pressure films in and out. 

With the horizontal hydraulic pistons, we applied 450 kPa normal stress at -2 degrees C and he measured the pressure on the films at 10 s, 100 s and 1000 s holds. The films were digitized and analyzed in ImageJ for %area. After lots of trouble shooting and trial and error to develop the protocol for this brand new method (for us anyway), his summer culminated in getting the below data set (Fig. b). It looks great! Well done, Will!