Surface-attached polymer networks that carry light-responsive nitrospiropyran groups in a hydrophilic PDMAA matrix were prepared on planar silicon and glass surfaces and were characterized with respect to their switching behavior under the influence of an external light trigger. Functional polymers bearing light-responsive units as well as photo-cross-linkable benzophenone groups were first synthesized using free radical copolymerization. The number of spiropyran groups in the copolymer was controlled by adjusting the concentration of the respective monomer in the copolymerization feed. The polymer films were prepared by spin-coating the functional polymers from solution and by ultraviolet light (UV)-induced cross-linking utilizing benzophenone photochemistry. On substrates with immobilized benzophenone groups, the complete polymer network is linked to the surface. The dry thickness of the films can be controlled over a wide range from a few nanometers up to more than 1 μm. The integration of such light-switchable organic moieties into a surface-attached polymer network allows one to increase the overall number of light-responsive groups per surface area by adjusting the amount of surface-attached polymer networks. The spiropyran's function in dry (solvent-free) and swollen polymer films can be reversibly switched by UV and visible irradiation. In addition, the switching in water is faster than in the dry state. Therefore, implementing light-responsive spiropyran functions in polymer films linked to solid surfaces could allow for switching of the chemical and optical surface properties in a fast and spatially controlled fashion.

In the following, the etching step index will be omitted whenever the other indices are similar for all etching steps. The data analysis procedure applied in this study can be divided in two main operations. The first operation is the extraction of the physical property. Here, each individual force distance curve , is analyzed on the theoretical basis explained in the 'Materials and Method' section of the main manuscript. The second operation is the structural and statistical analysis of the material properties.The result of the property extraction is a set of images with the same dimensionality as , .These physical maps contain quantitative information of material properties for each pixel within the array. These physical maps are:  The elasticity map , that represents the Young's modulus, computed from the re-trace portion of F k,l on the basis of the Derjaguin-Muller-Toporov (DMT) model. 1

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Small cantilevers with ultra-high resonant frequencies (1-3 MHz) have paved the way for high-speed atomic force microscopy. However, their potential for multi-frequency atomic force microscopy is unexplored. Because small cantilevers have small spring constants but large resonant frequencies, they are well-suited for the characterisation of delicate specimens with high imaging rates. We demonstrate their imaging capabilities in a bimodal frequency modulation mode in constant excitation on semi-crystalline polypropylene. The first two flexural modes of the cantilever were simultaneously excited. The detected frequency shift of the first eigenmode was held constant for topographical feedback, whereas the second eigenmode frequency shift was used to map the local properties of the specimen. High-resolution images were acquired depicting crystalline lamellae of approximately 12 nm in width. Additionally, dynamic force curves revealed that the contrast originated from different interaction forces between the tip and the distinct polymer regions. The technique uses gentle forces during scanning and quantified the elastic moduli Eam = 300 MPa and Ecr = 600 MPa on amorphous and crystalline regions, respectively. Thus, multimode measurements with small cantilevers allow one to map material properties on the nanoscale at high resolutions and increase the force sensitivity compared with standard cantilevers.