Figure 2From: Effect of substrate stiffness on early human embryonic stem cell differentiationSurface roughness measured by AFM. Height (Topography) of the three PDMS samples. A: PDMS 5: 1 RMS roughness: 1.0Â nm over 20 micron area B: PDMS 10: 1 RMS roughness: 0.8Â nm over 20 micron area C: PDMS 20: 1 RMS roughness: 0.8Â nm over 20 micron area.Back to article page