Figure 1
Description of the AFM methodology and representative images of the acquired topography and stiffness maps. (a) Schematic depiction of the setup employed to immobilize the alginate microspheres (left), and example of resulting maps for both topography and stiffness (right) measurements. A nylon mesh immobilized the microsphere allowing for stable measurements in liquid. The inset illustrates the indentation of the cantilever on top of the microsphere to acquire force spectroscopy measurements. Resulting data from force spectroscopy was then represented as topography maps (gold) and Young’s moduli were calculated and represented as stiffness maps (blue). (b) Representative topography images from alginate microspheres. Three sizes of maps were acquired per microsphere, a 100 μm2 general view (left), a 9 μm2 analysis view (center), and a 0.25 μm2 detailed view (right). The scales are optimized to provide optimal contrast to each image. Notably, optimal scale ranges decrease with higher magnification. (c) 3D representations of the topography maps presented in (b). (d) Stiffness maps acquired simultaneously to the maps presented in (b).
