Hierarchically patterned polyurethane microgrooves featuring nanopillars or nanoholes for neurite elongation and alignment

• Lester Uy Vinzons,
• Guo-Chung Dong and
• Shu-Ping Lin

Beilstein J. Nanotechnol. 2023, 14, 1157–1168, doi:10.3762/bjnano.14.96

• hierarchically structured microgrooves featuring nanopillars or nanoholes. Moreover, we found that replica molding using nano-/microstructured photoresist masters is a non-trivial step and requires specific “photoresist reinforcement” strategies to overcome inherent photoresist issues. Overall, our work

• crosslinked the imprinted SU-8 layer (Figure 1A(vi) and (vii)), resulting in a “reinforced” nanohole array (Figure 1A (viii)). Using these “reinforced” photoresist masters, PDMS replica molding and PU solvent casting allowed for the creation of the PU nanopillar and nanohole substrates (Figure 1B and

• seems necessary for more consistent results in the future.) As with the SU-8 nanopillar array, a “reinforcement” step consisting of hard-baking in cured PDMS (Figure 3A(iii)) was necessary for the pillar–groove master to prevent breakage of the nanopillars (Figure 3A(iv)). After PDMS replica molding and

Prediction of cytotoxicity of heavy metals adsorbed on nano-TiO₂ with periodic table descriptors using machine learning approaches

• Joyita Roy,
• Souvik Pore and
• Kunal Roy

Beilstein J. Nanotechnol. 2023, 14, 939–950, doi:10.3762/bjnano.14.77

• model depending on the previous one. In the bagging algorithm, replica data sets are generated that minimize prediction variance in machine learning. An iterative algorithm performs a series of repeated steps to gradually improve the model’s performance or to optimize a specific parameter. The

Industrial perspectives for personalized microneedles

• Remmi Danae Baker-Sediako,
• Benjamin Richter,
• Matthias Blaicher,
• Michael Thiel and
• Martin Hermatschweiler

Beilstein J. Nanotechnol. 2023, 14, 857–864, doi:10.3762/bjnano.14.70

• anchoring in barbed microneedles when compared to smooth microneedles [34]. Thus, it would be exciting to design microneedles, particularly those for pain management in joints, that are able to withstand a patient’s movements. Bio-inspired designs do not need to be an exact replica of their animal muse to

Interaction between honeybee mandibles and propolis

• Leonie Saccardi,
• Franz Brümmer,
• Jonas Schiebl,
• Oliver Schwarz,
• Alexander Kovalev and
• Stanislav Gorb

Beilstein J. Nanotechnol. 2022, 13, 958–974, doi:10.3762/bjnano.13.84

• 26 g, and S-1 dimethylaminoethanol 0.4 g [29]) and covered with a smooth sheet of dental wax to create a level surface for the mandible replica to stand on. The resin mandibles were cured at 70 °C for 48 h, demoulded and fixed to a glass slide using double-sided adhesive tape. A binocular microscope

• adhesion on mandibles”). For mandible replicas, reference measurements were performed on the smooth resin substrate. 50–60 single tests were performed on different spots of the mandible replica (N = 5–6 propolis samples and mandibles, n = 10 measurements on mandible per sample). Data analysis and

• material properties on propolis adhesion, further adhesion experiments were performed. The morphology of real mandibles including the microstructures were successfully replicated in mandible replica made from Spurr’s epoxy resin (Figure 11A). Propolis adhesion was subsequently tested on these replicated

Fabrication and testing of polymer microneedles for transdermal drug delivery

• Vahid Ebrahiminejad,
• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2022, 13, 629–640, doi:10.3762/bjnano.13.55

• (Figure 1h). After embossing, the chamber temperature was set to 10 °C for 15 minutes to cool down the PDMS and thermoplastic sample and solidify the replicated microstructure. The polymeric replica of the MN array was then carefully peeled off from the PDMS mold (Figure 1f). The entire replication

• fabrication of MN array master and replica The 9 × 9 MN arrays were successfully fabricated by TPP, and Zeonor 1060R replicas were made (>20 cycles) using hot embossing on PDMS mold. During the cycles, no damage was observed to the PMDS mold or its microcavities. Three 9 × 9 MN patch replicas were selected

Relationship between corrosion and nanoscale friction on a metallic glass

• Haoran Ma and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2022, 13, 236–244, doi:10.3762/bjnano.13.18

• phosphate buffer; (c) friction force of the inner layer and (d) friction force of the outer layer in NaCl solution. Solid lines are linear fits. Each data point is the average value of three replica experiments and error bars represent the standard deviation. The dependence on immersion time of: (a

Polarity in cuticular ridge development and insect attachment on leaf surfaces of Schismatoglottis calyptrata (Araceae)

• Venkata A. Surapaneni,
• Tobias Aust,
• Thomas Speck and
• Marc Thielen

Beilstein J. Nanotechnol. 2021, 12, 1326–1338, doi:10.3762/bjnano.12.98

• of adaxial leaf surfaces at various ontogenetic stages to study the morphological changes occurring on the leaf surfaces. We characterized the replica surfaces by using confocal laser scanning microscopy and commercial surface analysis software. The development of cuticular ridges is polar and the

• midrib (Figure 2). This could also be clearly observed from the difference in light reflection from the epoxy replicas. Figure 4 shows a typical epoxy replica of a leaf at stage 2 displaying the inclined ridge progression line. CLSM analysis showed that the surface of the transparent region of the epoxy

• replica corresponded to that of smooth unstructured cells, whereas the surface of the opaque region was covered with dense cuticular ridges. Analysis of individual epidermal cells demonstrated the change of size and orientation of the cells and the ridge islands during the ontogeny (Figure 5). Figure 5a

An overview of microneedle applications, materials, and fabrication methods

• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77

• to develop the next generation of polymer microneedle point-of-care tests and drug delivery patches will be photolithography, replica moulding, 3D printing, and micromachining. Photolithography involves polymerization of a liquid material by chemical modification through exposure to short wavelength

• , the exposure to UV light creates bonds through crosslinking whereby the exposed areas become less soluble in the developer [74][85]. In replica-moulding or micromoulding processes, a master (hard) mould is first produced. A liquid polymer solution, like polydimethylsiloxane (PDMS), is then deposited

• into the master mould and solidified by raised temperature (thermosetting), cooling, or UV curing to produce crosslinking. It can then be peeled from the master mould, which can be repeatedly reused to produce more replica moulds. To reduce the adhesion of the soft replica mould, the surface of the

Physical constraints lead to parallel evolution of micro- and nanostructures of animal adhesive pads: a review

• Thies H. Büscher and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2021, 12, 725–743, doi:10.3762/bjnano.12.57

• coverage. Similar data have been obtained for the chrysomelid beetle Hemisphaerota cyanea (Chrysomelidae, Cassidinae) [261]. In smooth insect pads, the pad secretion consists of a water-soluble and a lipid-soluble part [254]. Data obtained from shock-freezing, carbon–platinum coating, and replica

• Clearance Center, Inc.. This content is not subject to CC BY 4.0. Fluid micro- and nanodrops in animal attachment pads. (A) Carbon–platinum replica of frozen and coated droplets of the fly Calliphora vicina in SEM (black arrow indicates the direction of coating). Please note the pattern of nanodrops on the

Application of contact-resonance AFM methods to polymer samples

• Sebastian Friedrich and
• Brunero Cappella

Beilstein J. Nanotechnol. 2020, 11, 1714–1727, doi:10.3762/bjnano.11.154

• resulting image is a replica of the AFM tip [43][44]. An example of tip imaging is shown in Supporting Information File 1, Figure S3. Single-point CR measurements have been conducted by performing a frequency sweep (tune), while the tip has been in contact with the sample, and identifying the contact

Electrokinetic characterization of synthetic protein nanoparticles

• Daniel F. Quevedo,
• Cody J. Lentz,
• Adriana Coll de Peña,
• Yazmin Hernandez,
• Nahal Habibi,
• Rikako Miki,
• Joerg Lahann and
• Blanca H. Lapizco-Encinas

Beilstein J. Nanotechnol. 2020, 11, 1556–1567, doi:10.3762/bjnano.11.138

• posts (Figure 2b and Figure S1, Supporting Information File 1) were made from PDMS employing standard soft lithography techniques. To create a device, PDMS (Dow Corning, Midland, MI) was cast onto a negative replica mold made with a silicon wafer (Silicon Inc., Boise, ID) and an SU-8 3050 photoresist

Integration of sharp silicon nitride tips into high-speed SU8 cantilevers in a batch fabrication process

• Nahid Hosseini,
• Matthias Neuenschwander,
• Oliver Peric,
• Santiago H. Andany,
• Jonathan D. Adams and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2019, 10, 2357–2363, doi:10.3762/bjnano.10.226

• blunt tips (the tip radius increased by an order of magnitude). Lee et al. have shown that hydrogel AFM cantilevers fabricated by replica moulding and UV curing have great potential for tuning the mechanical properties of the tip, its shape and the surface functionalization [26]. However, the

Coexisting spin and Rabi oscillations at intermediate time regimes in electron transport through a photon cavity

• Vidar Gudmundsson,
• Hallmann Gestsson,
• Nzar Rauf Abdullah,
• Chi-Shung Tang,
• Andrei Manolescu and
• Valeriu Moldoveanu

Beilstein J. Nanotechnol. 2019, 10, 606–616, doi:10.3762/bjnano.10.61

• photon replica in the bias window. Figure 5 shows clear Rabi oscillations in IR and much weaker in IL. The Rabi oscillations are a bit faster for the x-polarized photon field than the y-polarized in accordance with the Rabi energies readable from the anticrossing levels in Figure 3. Additionally, we

• spin components of the lowest in energy one-electron states, mostly localized in the left dot (shallower) and the first photon replica of the corresponding states in the right dot (deeper) as the energy of the cavity photon EEM = is varied. Vg = 0 mV. For Vg = 1.6 mV the states are labeled with and

Ultraviolet patterns of flowers revealed in polymer replica – caused by surface architecture

• Anna J. Schulte,
• Matthias Mail,
• Lisa A. Hahn and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2019, 10, 459–466, doi:10.3762/bjnano.10.45

• the reflectivity of the UV-absorbing and the UV-reflecting areas within one petal as well as between the three model flowers. For this investigation, spectral measurements were performed as described in the Experimental section. As a reference, a smooth surface made of the replica polymer was used

• in the laboratory as well. While the smooth reference reflects about 5.8% (r = 5.8%) of the incoming light, the highest reflection value of the structured replicas was demonstrated by the replica of the UV-reflecting area of E. manescavii (r = 3.5%). The replica of the UV-absorbing area of R. fulgida

• electromagnetic radiation into the petals. They also support the assumption that the transmission of UV-light into the petal and replica is also supported by the surface structure. Therefore, even if the pigments essentially cause the UV-patterns in petals, the surface structure at the petal adaxial surface also

A comparison of tarsal morphology and traction force in the two burying beetles Nicrophorus nepalensis and Nicrophorus vespilloides (Coleoptera, Silphidae)

• Liesa Schnee,
• Benjamin Sampalla,
• Josef K. Müller and
• Oliver Betz

Beilstein J. Nanotechnol. 2019, 10, 47–61, doi:10.3762/bjnano.10.5

• under a binocular dissection microscope. After one day of recovery, the experiments were repeated. Each beetle was presented with one replica of each test surface in a random order. In total, the experiments were conducted with 20 individuals (10 males, 10 females) per species. Body weights were

Block copolymers for designing nanostructured porous coatings

• Roberto Nisticò

Beilstein J. Nanotechnol. 2018, 9, 2332–2344, doi:10.3762/bjnano.9.218

• structural directing agents (SDAs) [97][98]. This way, the final material corresponds to the negative replica of the SDA. There are two principal templating methods: hard templating (or nanocasting) and soft templating [97]. Hard templating involves an exotemplating approach, where the precursor solidifies

Preparation of micro/nanopatterned gelatins crosslinked with genipin for biocompatible dental implants

• Reika Makita,
• Tsukasa Akasaka,
• Seiichi Tamagawa,
• Yasuhiro Yoshida,
• Saori Miyata,
• Hirofumi Miyaji and
• Tsutomu Sugaya

Beilstein J. Nanotechnol. 2018, 9, 1735–1754, doi:10.3762/bjnano.9.165

• rubber replica molds were prepared according to methods previously reported [11][12][14]. Quartz and silicon master molds were purchased from Kyodo International, Inc. (Kawasaki, Japan). An area of 5 × 5 mm2 was patterned as follows: Grooves/ridges, holes, pillars with width or diameter of 2 µm, 1 µm, or

• COP film, a COP replica mold was obtained. In addition, the PDMS pre-polymer (KE-106 and CAT-RG, 10:1 mix; Shin-Etsu Chemical, Tokyo, Japan) [75] was cast against the above-mentioned replica COP mold and degassed under a vacuum. The PDMS was then heat-cured at 60 °C for 12 h, and then at 100 °C for 3

• days. Upon peeling off the cured polymer, a PDMS replica mold with a 0.5 mm thickness was obtained. Figure 11 shows the procedure for the fabrication of gelatin-containing micro/nanopatterns using genipin crosslinking. The gelatin powder was obtained from porcine skin (G1890, type A, gel strength: ≈300

Evaluation of replicas manufactured in a 3D-printed nanoimprint unit

• Manuel Caño-García,
• Morten A. Geday,
• Manuel Gil-Valverde,
• Xabier Quintana and
• José M. Otón

Beilstein J. Nanotechnol. 2018, 9, 1573–1581, doi:10.3762/bjnano.9.149

• of a solvent were found to be superior for most nanoimprint applications. A large dispersion of the samples was found. Keywords: nanoimprint; oriented gradient; photoresist; polymer; replica; Introduction Although the basic principles behind nanoimprint lithography (NIL) have been known for many

• sample master and all 103 replica samples are presented. The bottom graphs are averaged figures of merit gathering all parameters (left) and singularizing every parameter (right). Acknowledgements Authors are indebted for financial help received from the “Programa RETOS” from the Ministerio de Economía

Robust procedure for creating and characterizing the atomic structure of scanning tunneling microscope tips

• Sumit Tewari,
• Koen M. Bastiaans,
• Milan P. Allan and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2017, 8, 2389–2395, doi:10.3762/bjnano.8.238

• not have circular symmetry. In order to verify that this asymmetry is associated with the tip, we deposit a second adatom. The image of the second atom is a replica of the first, in shape and orientation, confirming that the asymmetry is associated with the tip shape. In the next steps we use an

Increasing the stability of DNA nanostructure templates by atomic layer deposition of Al₂O₃ and its application in imprinting lithography

• Hyojeong Kim,
• Kristin Arbutina,
• Anqin Xu and
• Haitao Liu

Beilstein J. Nanotechnol. 2017, 8, 2363–2375, doi:10.3762/bjnano.8.236

• resistive to UV/O3 oxidation. The ALD-coated DNA templates were used for a direct pattern transfer to poly(L-lactic acid) films. Keywords: aluminium oxide (Al2O3); atomic layer deposition; DNA nanostructure; nanofabrication; nanoimprint lithography; pattern transfer; polymer stamp; replica molding

• from the template (Figure 1e). Droplets of water were added to the exposed edges of the template, separating the hydrophobic PLLA film from the hydrophilic master template by penetration into the interface between them. After one minute, the PLLA/PDMS film was peeled off and the negative replica of the

• , and (e) 15 days after pattern transfer of the same area. White lines on the AFM images indicate where the cross-sections were determined. (f) Height/depth and (g) FWHM of the DNA nanotubes and their replica trenches in four different locations of the AFM images from (a) to (e). Locations 1, 2, 3, and

Identifying the nature of surface chemical modification for directed self-assembly of block copolymers

• Laura Evangelio,
• Federico Gramazio,
• Matteo Lorenzoni,
• Michaela Gorgoi,
• Francisco Miguel Espinosa,
• Ricardo García,
• Francesc Pérez-Murano and
• Jordi Fraxedas

Beilstein J. Nanotechnol. 2017, 8, 1972–1981, doi:10.3762/bjnano.8.198

• affinity of the PS–OH brush layer (see middle of Figure 1) [12]. The third method (PON) [18], shown in the bottom of Figure 1, is performed by contacting a conductive mold with the PS–OH surface while applying a voltage under conditions of high humidity. The stamp consists of a 1 cm2 piece of a DVD replica

Air–water interface of submerged superhydrophobic surfaces imaged by atomic force microscopy

• Markus Moosmann,
• Thomas Schimmel,
• Wilhelm Barthlott and
• Matthias Mail

Beilstein J. Nanotechnol. 2017, 8, 1671–1679, doi:10.3762/bjnano.8.167

• structure. Architecture of the epoxy replica samples used in this study. a) SEM image of a sample with micro-pillars on its surface (top view). b) Schematic cross-section of the periodically ordered micro-pillars on the surface (height 2 µm, diameter 1 µm, pitch 2.5 µm). Photographic images of a submerged

Micro- and nano-surface structures based on vapor-deposited polymers

• Hsien-Yeh Chen

Beilstein J. Nanotechnol. 2017, 8, 1366–1374, doi:10.3762/bjnano.8.138

• ]. Also, printing methods with elastomeric stamps or replica structures to transfer a material from a solution onto a surface, which are collectively related to imprinting lithography [15][16] or soft lithography [17][18], were developed. Thus, the early developments of the patterning and structuring

• ]. The multifunctional interfaces with pattern structures were demonstrated by separately depositing alkyne-functionalized poly(p-xylylene) and aldehyde-functionalized poly(p-xylylene) in selected areas using a vapor-assisted micropatterning in the replica structure (VAMPIR) technique [55][56]. The

• coatings, and a concept is shown to immobilize multiple functional molecules at corresponding areas. (b) Patterning/structuring on layered polymer coatings by a vapor-assisted micropatterning in the replica structure (VAMPIR) technique, in which a microstencil is exploited during the vapor deposition

Nanotopographical control of surfaces using chemical vapor deposition processes

• Meike Koenig and
• Joerg Lahann

Beilstein J. Nanotechnol. 2017, 8, 1250–1256, doi:10.3762/bjnano.8.126

• deposition Microstructured masks can be applied to cover parts of the substrate in order to prevent deposition of polymer on these locations [8][9]. Chen and Lahann developed the vapor-assisted micropatterning in replica structures (VAMPIR) method using poly(dimethylsiloxane) (PDMS) masks to pattern reactive

Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

• Alexandra M. Greiner,
• Adria Sales,
• Hao Chen,
• Sarah A. Biela,
• Dieter Kaufmann and
• Ralf Kemkemer

Beilstein J. Nanotechnol. 2016, 7, 1620–1641, doi:10.3762/bjnano.7.155

• order to give an overview of different microfabrication techniques, relevant examples for different approaches such as optical (photolithography [49]), mechanical (hot embossing [50] and surface cracking [51][52]) or chemical (replica molding [53][54], phase separation micromolding [55][56][57], gas

• form the topography of the features in the plastic. Similar to replica molding in soft lithography, features down to around 10 nm can be replicated. Like soft lithography hot embossing is a cheap method suitable for large-scale manufacturing of substrates [50]. In principle, it can be used with many

• cell adaptation to dynamic changes of the substrate topography [51][52]. Replica molding is a soft lithography technique that uses an elastomeric soft material to replicate patterns (Figure 4B) [53][54]. With that method mainly micrometer-sized topographies are produced in the elastomer. Structures