TY - JOUR A1 - Lifka, S. A1 - Harsányi, K. A1 - Baumgartner, E. A1 - Pichler, L. A1 - Baiko, D. A1 - Wasmuth, Karsten A1 - Heitz, J. A1 - Meyer, M. A1 - Joel, A.-C. A1 - Bonse, Jörn A1 - Baumgartner, W. ED - Mail, M. T1 - Laser-processed antiadhesive bionic combs for handling nanofibers inspired by nanostructures on the legs of cribellate spiders JF - Beilstein Journal of Nanotechnology N2 - Nanofibers are drawing the attention of engineers and scientists because their large surface-to-volume ratio is favorable for applications in medicine, filter technology, textile industry, lithium-air batteries, and optical sensors. However, when transferring nanofibers to a technical product in the form of a random network of fibers, referred to as nonwoven fabric, the stickiness of the freshly produced and thus fragile nanofiber nonwoven remains a problem. This is mainly because nanofibers strongly adhere to any surface because of van der Waals forces. In nature, there are animals that are actually able to efficiently produce, process, and handle nanofibers, namely cribellate spiders. For that, the spiders use the calamistrum, a comb-like structure of modified setae on the metatarsus of the hindmost (fourth) legs, to which the 10–30 nm thick silk nanofibers do not stick due to a special fingerprint-like surface nanostructure. In this work, we present a theoretical model of the interaction of linear nanofibers with a sinusoidally corrugated surface. This model allows for a prediction of the adhesive interaction and, thus, the design of a suitable surface structure to prevent sticking of an artificially nonwoven of nanofibers. According to the theoretical prediction, a technical analogon of the nanoripples was produced by ultrashort pulse laser processing on different technically relevant metal surfaces in the form of so-called laser-induced periodic surface structures (LIPSS). Subsequently, by means of a newly established peel-off test, the adhesion of an electrospun polyamide fiber-based nonwoven was quantified on such LIPSS-covered aluminium alloy, steel, and titanium alloy samples, as well as on polished (flat) control samples as reference and, additionally, on samples with randomly rough surfaces. The latter revealed that the adhesion of electrospun nanofiber nonwoven is significantly lowered on the nanostructured surfaces compared with the polished surfaces. KW - Laser-induced periodic surface structures (LIPSS) KW - Cribellate spiders KW - Calamistrum KW - Electrospinning KW - Nanofibers PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561799 DO - https://doi.org/10.3762/bjnano.13.105 SN - 2190-4286 VL - 13 SP - 1268 EP - 1283 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, M. AN - OPUS4-56179 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Anja A1 - Buchberger, G. A1 - Stifter, D. A1 - Duchoslav, J. A1 - Hertwig, Andreas A1 - Bonse, Jörn A1 - Heitz, J. A1 - Schwibbert, Karin T1 - Spatial Period of Laser-Induced Surface Nanoripples on PET Determines Escherichia coli Repellence JF - Nanomaterials N2 - Bacterial adhesion and biofilm formation on surfaces are associated with persistent microbial contamination, biofouling, and the emergence of resistance, thus, calling for new strategies to impede bacterial surface colonization. Using ns-UV laser treatment (wavelength 248 nm and a pulse duration of 20 ns), laser-induced periodic surface structures (LIPSS) featuring different submicrometric periods ranging from ~210 to ~610 nm were processed on commercial poly(ethylene terephthalate) (PET) foils. Bacterial adhesion tests revealed that these nanorippled surfaces exhibit a repellence for E. coli that decisively depends on the spatial periods of the LIPSS with the strongest reduction (~91%) in cell adhesion observed for LIPSS periods of 214 nm. Although chemical and structural analyses indicated a moderate laser-induced surface oxidation, a significant influence on the bacterial adhesion was ruled out. Scanning electron microscopy and additional biofilm studies using a pili-deficient E. coli TG1 strain revealed the role of extracellular appendages in the bacterial repellence observed here. KW - Laser-induced periodic surface structures (LIPSS) KW - Laser processing KW - Polyethylene terephthalate KW - Biofilm formation KW - Cell appendages KW - Biomimetic KW - F pili PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537431 DO - https://doi.org/10.3390/nano11113000 VL - 11 IS - 11 SP - 3000 PB - MDPI AN - OPUS4-53743 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -