CLeANFIT – Contact‐Less Axial Nearfield‐Based Fluorescence Imaging Topography: A Method for 3D Micro‐ and Nanotopography Characterization

Abstract A nearfield‐based topographic imaging method is presented to obtain 3D micro‐/nanotopography in labelled structures over lateral ranges of hundreds of micrometers with an axial thickness from 1000 nm to thin layers of below 100 nm. The contactless axial nearfield‐based fluorescence imaging topography (CLeANFIT) nanometrology technique is based on a modified model used in nearfield‐based super‐resolution imaging and sensing. The modified approach allows converting fluorescence lifetimes into nanoscale thicknesses of a fluorescent material in the nearfield of a metal surface. CLeANFIT is used to characterize the drying process of a fluorophore‐doped poly(vinyl alcohol)/water droplet and it allows to quantify the nanomorphological patterns formed during and after drying. CLeANFIT allows axial resolution similar to tip scanning techniques, while remaining contact‐free. Therefore, no damage occurs to the target allowing in situ studies. The final drying stage of droplet is analyzed through quantifying contact line dynamics. The axial sensitivity of CLeANFIT, makes it an exceptional technique to study interactions and dynamic phenomena at the liquid/solid interfaces in nanoscale dimensions, relevant for the development of novel nanomaterials, nanocoatings, and hybrid nanotechnology‐enabled integrated chips, that may be fabricated via nanoinkjet printing, photolithography, nanoimprint lithography, or other micro‐/nanofabrication techniques.