Well-defined polymer strands covalently tethered onto solid substrates determine the properties of the resulting functional interface. Herein, the current approaches to determine quantitative grafting densities are assessed. Based on a brief introduction into the key theories describing polymer brush regimes, a user's guide is provided to estimating maximum chain coverage and-importantly-examine the most frequently employed approaches for determining grafting densities, i.e., dry thickness measurements, gravimetric assessment, and swelling experiments. An estimation of the reliability of these determination methods is provided via carefully evaluating their assumptions and assessing the stability of the underpinning equations. A practical access guide for comparatively and quantitatively evaluating the reliability of a given approach is thus provided, enabling the field to critically judge experimentally determined grafting densities and to avoid the reporting of grafting densities that fall outside the physically realistic parameter space. The assessment is concluded with a perspective on the development of advanced approaches for determination of grafting density, in particular, on single-chain methodologies.

A new class of photoresist consisting of two polymers, which respond in a -orthogonal fashion, i.e. each photochemical crosslinking step is exclusively responding to a specific wavelength, is pioneered. The innovation enables the spatially resolved fabrication of disparate materials and properties from one photoresist as a function of only the colour of light.

Polymer chains are grafted depending on their size onto solid interfaces, leading to a distortion of the surface grafted size distribution. We herein predict and quanitify this distortion effect, which has critical consequences for functional polymer interface design.

The selective removal of structural elements plays a decisive role in three-dimensional (3D) printing applications enabling complex geometries. To date, the fabrication of complex structures on the microscale is severely limited by multi-step processes. Herein, we report a subtractive photoresist platform technology that is transferable from microscopic 3D printing via Direct Laser Writing (DLW) to macroscopic structures via Stereolithography (SLA). All resist components are readily accessible and exchangeable, offering fast adaptation of the resist's property profile. The micro-and macroprinted structures can be removed in a facile fashion, without affecting objects based on standard photoresists. The cleavage is analyzed by time-lapse images as well as via in-depth spectroscopic assessment. The mechanical properties of the printed materials are investigated by nanoindentation. Critically, we demonstrate the power of our subtractive resist platform by constructing complex 3D objects with flying features on the microscale.