Strain-Induced Raman Shifts Due to Ice Adhesion

When ice is formed on a material, it creates a strain proportional to the adhesive strength between the ice and substrate. In order to quantify this adhesion, we use Raman spectroscopy to measure the vibrational modes of various materials with and without ice. Carbon nanotubes, gold nanoparticles, and Raman-tagged gold nanoparticles were used to isolate effects at the interface where the largest strain occurs. The temperature of the substrate at the interface was measured using the intensity ratio of the Stokes and anti-Stokes shifts, allowing us to account for the temperature dependence of the vibrational modes. Preliminary data on silicon and aluminum suggests that ice causes the Raman modes to shift to higher energies. This optical data, calibrated with mechanical measurements, provides a non-destructive technique to measure adhesive strength.