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Mikroskopija atomskih sil (ang.: atomic force microscopy AFM) je ena od oblik mikroskopij, ki omogoča opazovanje neprevodnih površin v nanometrskem merilu. Razvila sta jo Nobelova nagrajenca s področja fizike, Binnig in Roher [5, 6]. Od izuma leta 1986 pa do danes je mikroskop atomskih sil postal zelo pomemben inštrument v laboratorijih za fiziko trdnih snovi, kemijskih, polimernih in bioloških laboratorijih, pojavlja pa se tudi že v industriji. Izredno uporaben je na področju tekstilstva, čeprav njegovih zmožnosti na tem področju do sedaj še niso intenzivneje raziskali. Struktura vlaken je zapletena. Večinoma je morfologija površine drugačna od tiste v notranjosti. Oblika površine vlaken vpliva na procese, ki se odvijajo na mejnih površinah. Zato je toliko bolj pomembno uvajanje novih metod na področje analize površinskih lastnosti vlaken. Mikroskop atomskih sil AFM nudi informacije o fibrilni strukturi vlaken, poleg tridimenzionalne analize površine vlaken omogoča tudi merjenje medmolekulskih in medatomskih sil velikostnega reda nekaj nN. V primerjavi z elektronskim mikroskopom je priprava vzorca mnogo enostavnejša. V prispevku je opisan princip delovanja AFM in predstavljeni rezultati analize PAG filamenta. Na površini PA6 monofilamenta je vidna fibrilna struktura. Najmanjši fibrili, ki jih je mogoče razločiti, imajo premer le nekaj 10 nm. Združujejo se v večje fibrilne snope, ki v najširših predelih merijo 1 do 2 μm. Praznine in vdolbine na površini so različno velike (30-200 nm) in so okrogle ali ovalne oblike, usmerjene v smeri osi vlakna. Površina filamenta je v smeri osi vlakna manj razbrazdana višinska razlika med najnižjimi in najvišjimi področji znaša v prečni smeri do 70 nm, v vzdolžni smeri pa do 30 nm. Atomic force microscopy (AFM) is one of the most modem types of microscopy enabling nanoscale imaging of both conducting and insulating surfaces. It was developed by the Nobel Prize winners in physics, Binning and Roher. Since its invention in 1986 the atomic force microscope has become useful in industry and as a very important laboratory instrument in different fields of research such as physics, chemistry, polymers and biology. This method can also be applied in textile research although the researchers working in this field are few. The structure of fibres is very complex. In most cases the morphology of the fibre surface differs from the morphology of the core. The characteristics of the fibre surface influence the processes at the interfaces which makes any surface analysis of the fibres extremely important, and the introduction of new methods valuable. AFM gives a three-dimensional nanoscale image of the surface thus revealing additional information about the fibrillar structure of the fibres. It can also be used for intermolecular and intercolloidal force measurements sensing forces even smaller than 1 nN. A sample preparation prior to imaging is much simpler compared to electron microscopy. In this paper the basic AFM operation is discussed and the topography of PA6 filament is analysed using AFM. The fibrillar structure can be seen at the fibre surface. The smallest detectable fibrils are in the range of about 10 nm in width. They are congregated in bigger fibril bundles having up to 1-2 μm in diameter. Cavities and niches vary in width (30-200 nm) and shape (round or oblong). They are oriented in the direction of the fibre. The surface of the filament is less furrowed in the direction of the fibre the difference in height between the highest and the lowest regions alongside is only up to 30 nm and transverse up to 70 nm.