Mmafm 2

The surface topography was measured for the fully cured thin and thick films. Therefore, a MultiMode (MMAFM-2, Bruker Corporation) AFM with a silicon nitride-based cantilever for soft materials (SCANASYST-AIR-HR, spring constant: 0.4 N/m, resonance frequency: 130 kHz, Bruker Corporation) with a nominal tip radius of 2 nm in tapping mode was used. The topographic measurements were conducted on 3 positions on the sample with a scan size of (10 × 10) µm², to check the surface homogeneity. The root-mean-square roughness was also analyzed from these topographic measurements. For thickness determination, the film was scratched, and the scratch imaged with the AFM. The resulting step was then linearly integrated and leveled to obtain the thickness.

DNA nanotubes on wafers were imaged using ‘Peak Force’ tapping mode AFM (MMAFM-2, Bruker, Santa Barbara, CA) with Bruker ScanAsyst automatic image optimization technology and Bruker silicon tips on nitride cantilevers.