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

• any microstructure directly from the CAD design file. We now consider in more detail the most important microneedle materials and their fabrication and uses. Fabrication and use of silicon microneedles Silicon microneedles have, to date, been the most common type, using microfabrication methods with

• high, were formed by exposing SU-8 polymer, on a silicon wafer, to UV light through a mask consisting of hollow circular patterns or annuli [101], followed by wet development to obtain the final microstructure. In recent years, techniques such as 3D printing and TPP have received great interest due to

• biosensors, micropumps, microfluidic chips, and microelectronic devices. The choice of manufacturing techniques for microneedles is dependent on material properties, fabrication cost, and desired height and shape of the microstructure. Hollow microneedles can actively deliver drugs into the skin, but due to

Is the Ne operation of the helium ion microscope suitable for electron backscatter diffraction sample preparation?

• Annalena Wolff

Beilstein J. Nanotechnol. 2021, 12, 965–983, doi:10.3762/bjnano.12.73

• study of microstructure, grain size, and orientation as well as strain of a crystallographic sample. In addition, the technique can be used for phase analysis. A mirror-flat sample surface is required for this analysis technique and different polishing approaches have been used over the years. A

• here looks at the ion-beam-induced artefacts when polishing copper for EBSD measurements for different ion species (Ga, Ne) as well as polishing protocols. EBSD is a characterization technique in scanning electron microscopes (SEMs) that allows for the study of microstructure, local texture, grain size

• displayed in red. The KAM maps (Figure 7f and Figure 7h) show a significantly higher level of misorientation in the irradiated sample (shown in green in the map). The measurements suggest changes in the microstructure and this is in good agreement with the TEM measurements which suggested a higher defect

Effects of temperature and repeat layer spacing on mechanical properties of graphene/polycrystalline copper nanolaminated composites under shear loading

• Chia-Wei Huang,
• Man-Ping Chang and
• Te-Hua Fang

Beilstein J. Nanotechnol. 2021, 12, 863–877, doi:10.3762/bjnano.12.65

• that even random graphene fragments can improve the mechanical properties of composites. However, it is challenging to tailor the mechanical properties by controlling the proportion of graphene since the mechanical behavior of graphene composites is associated with the microstructure [20][21

• this work, we focus on temperature and microstructure effects on graphene/polycrystalline copper nanolaminated (GPCuNL) composites. As mentioned above, the microstructure plays a crucial role for the mechanical behavior of GPCuNL composites. Thus, in the present study, molecular dynamics (MD

Recent progress in actuation technologies of micro/nanorobots

• Ke Xu and
• Bing Liu

Beilstein J. Nanotechnol. 2021, 12, 756–765, doi:10.3762/bjnano.12.59

• the possibility to apply accurate drug delivery in peripheral blood vessels. Valdez‐Garduño et al. [36] proposed a new method that uses an external magnetic field to fix the direction of a micromotor and converts the ultrasound-induced oscillation motion of a Janus microstructure with asymmetric

• density into a translational motion. The acoustic movement of the Janus microstructure is based on the selection of materials with different densities and shapes. Experiments show that density asymmetry causes uneven oscillations and generates a flow at the boundary. Geometric asymmetry enhances the flow

• and provides a driving force for translational motion. In addition to ultrasonic driving, the Janus microstructure in this method can also be propelled by magnetic fields or chemical driving. This research provides a new option for the design and application of ultrasonic propulsion micro/nanomotors

Recent progress in magnetic applications for micro- and nanorobots

• Ke Xu,
• Shuang Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2021, 12, 744–755, doi:10.3762/bjnano.12.58

• ]. Wang et al. [83] successfully fabricated a biocompatible and pH-responsive magnetic helical microstructure coated with zinc-based MOF and zeolite imidazole framework-8 (ZIF-8). They also developed a helical swimmer with 2PP, also called artificial bacterial flagella, as shown in Figure 2. In order to

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

• ], all attachment pads of Phasmatodea are smooth; however, they are covered with functional surface microstructures. Although the arolia are rather uniform in their morphology, their surface microstructure reflects the basal sister-group relationship of Timema and Euphasmatodea (all remaining Phasmatodea

• the euplantular AMS suggests a high dependence of the microstructure to the habitat of the species. Ground-dwelling stick insects reveal nubby microstructures unrelated to their phylogenetic position, as well as canopy-dwelling species, which possess smooth structures without cuticular patterns on the

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

Rapid controlled synthesis of gold–platinum nanorods with excellent photothermal properties under 808 nm excitation

• Jialin Wang,
• Qianqian Duan,
• Min Yang,
• Boye Zhang,
• Li Guo,
• Pengcui Li,
• Wendong Zhang and
• Shengbo Sang

Beilstein J. Nanotechnol. 2021, 12, 462–472, doi:10.3762/bjnano.12.37

• wavelength. In addition, the microstructure of metal nanomaterials, especially the aspect ratio (ratio between length and width), determines the position of the LSPR peak. Therefore, regulating the microstructure of nanomaterials is an effective means to control the LSPR wavelength. Au nanomaterials

Spontaneous shape transition of Mn_xGe_1−x islands to long nanowires

• S. Javad Rezvani,
• Luc Favre,
• Gabriele Giuli,
• Yiming Wubulikasimu,
• Isabelle Berbezier,
• Augusto Marcelli,
• Luca Boarino and
• Nicola Pinto

Beilstein J. Nanotechnol. 2021, 12, 366–374, doi:10.3762/bjnano.12.30

• report a spontaneous morphology modification, from islands to nanowires, in Mn-rich GeMn nanoparticles. The growth is initiated via reaction of a thin Mn wetting layer, evaporated by MBE, with a Ge(111) substrate. Morphology and microstructure of the NWs have been studied by scanning electron microscopy

Self-standing heterostructured NiC_x-NiFe-NC/biochar as a highly efficient cathode for lithium–oxygen batteries

• Shengyu Jing,
• Xu Gong,
• Shan Ji,
• Linhui Jia,
• Bruno G. Pollet,
• Sheng Yan and
• Huagen Liang

Beilstein J. Nanotechnol. 2020, 11, 1809–1821, doi:10.3762/bjnano.11.163

• and the NaOH solution, resulting in a Ni(OH)2/NiFe-PBA core–shell structure [44][45][46]. During the calcination process, Ni(OH)2 was converted into NiCx, and the NiFe-PBA core was converted into a NiFe alloy coated with N-doped carbon. The microstructure of NiFe-PBA/PP-T was evaluated by SEM. Figure

3D superconducting hollow nanowires with tailored diameters grown by focused He⁺ beam direct writing

• Rosa Córdoba,
• Alfonso Ibarra,
• Dominique Mailly,
• Isabel Guillamón,
• Hermann Suderow and
• José María De Teresa

Beilstein J. Nanotechnol. 2020, 11, 1198–1206, doi:10.3762/bjnano.11.104

• to 8.9 µm. Transmission electron microscopy experiments indicate that the nanowires have a microstructure of large grains with a crystalline structure compatible with the face-centered cubic WC1−x phase. In addition, 3D electron tomographic reconstructions show that the hollow center of the nanowires

• deposited W-based pillars with diameters down to approx. 40 nm and aspect ratios of approx. 50. The microstructure of the grown material consisted of fcc WC1−x and W2(C,O) grains. Moreover, when the He+ beam was well focused the authors observed columnar voids created at the center of the pillars with a

• (aspect ratio ≈ 196). These values are significantly better than those reported in previous works [17][35]. The NWs microstructure consists of large grains of fcc WC1−x, in good agreement with [17][35]. In addition, the NWs are hollow along the whole NW length, which could make them nonconventional

Wet-spinning of magneto-responsive helical chitosan microfibers

• Dorothea Brüggemann,
• Johanna Michel,
• Naiana Suter,
• Matheus Grande de Aguiar and
• Michael Maas

Beilstein J. Nanotechnol. 2020, 11, 991–999, doi:10.3762/bjnano.11.83

• . This strategy is based on wet-spinning of magnetic fibers, which are collected on a rotating needle controlled by an external magnetic field with a predefined helical geometry. The fibers were characterized regarding their morphology, microstructure, magnetization and mechanical characteristics. These

A 3D-polyphenylalanine network inside porous alumina: Synthesis and characterization of an inorganic–organic composite membrane

• Jonathan Stott and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2020, 11, 938–951, doi:10.3762/bjnano.11.78

• spectroscopic analysis provides qualitative information of the secondary structure of the grafted poly(amino acids). The measurement of the water contact angle allows conclusions regarding the hydrophobic or hydrophilic properties of the functionalized surface as well as the microstructure of the grafted

• polymer films at the outer surface. Thermogravimetric measurements were used to determine the amount of strong and weakly bonded polymers inside the ALOX-membrane. Finally, SEM was used to investigate the microstructure and morphology of the grafted polymers at the outer surface as well the inner surface

• of the ALOX-membranes. Previous experiments showed a significant influence of the used solvent on the microstructure of the grafted polyphenylalanine (pPA) within the pore volume of the macroporous ALOX-membranes. The polymerization of 100 mM pPA-NCA monomer solutions in pure THF results in a flat

Nickel nanoparticles supported on a covalent triazine framework as electrocatalyst for oxygen evolution reaction and oxygen reduction reactions

• Secil Öztürk,
• Yu-Xuan Xiao,
• Dennis Dietrich,
• Beatriz Giesen,
• Juri Barthel,
• Jie Ying,
• Xiao-Yu Yang and
• Christoph Janiak

Beilstein J. Nanotechnol. 2020, 11, 770–781, doi:10.3762/bjnano.11.62

• organic frameworks (MOF) with or without a nitrogen source [13][43][44]. An important step in these syntheses is high-temperature pyrolysis under inert atmosphere for a few hours. However, these methods often cannot control the nitrogen microstructure and composition. In contrast, Ni/CTF-1 is obtained in

Correction: An advanced structural characterization of templated meso-macroporous carbon monoliths by small- and wide-angle scattering techniques

• Felix M. Badaczewski,
• Marc O. Loeh,
• Torben Pfaff,
• Dirk Wallacher,
• Daniel Clemens and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2020, 11, 678–679, doi:10.3762/bjnano.11.54

• Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin, Germany, Center for Materials Research (LaMa), Justus-Liebig-University, Heinrich-Buff-Ring 16, 35392 Giessen, Germany 10.3762/bjnano.11.54 Keywords: adsorption; carbon materials; mesoporosity; microporosity; microstructure; pore

A novel dry-blending method to reduce the coefficient of thermal expansion of polymer templates for OTFT electrodes

• Xiangdong Ye,
• Bo Tian,
• Yuxuan Guo,
• Fan Fan and
• Anjiang Cai

Beilstein J. Nanotechnol. 2020, 11, 671–677, doi:10.3762/bjnano.11.53

• 15 × 15 × 1 mm, with the structure of the array on the template surface in the upper right corner. Figure 3b shows the microstructure of the PDMS/SiO2 composite template. The width is uniform and the structure is complete, and the surface of the composite template is clean. The cross-sectional

• morphology of the composite template is shown in Figure 3c. The edges of columnar microstructure are smooth and complete, which indicates that the PDMS template can be peeled off from the silicon template without damaging the structures. Calculating the weight fraction of the SiO2 nanoparticles To calculate

• peeling off the PDMS film. Surface morphology of the PDMS/SiO2 composite template. (a) Physical appearance of the PDMS/SiO2 composite template. (b) Microstructure of the PDMS/SiO2 composite template. (c) Cross-sectional microstructure of the PDMS/SiO2 composite template. Strain–temperature curves of PDMS

Preparation, characterization and photocatalytic performance of heterostructured CuO–ZnO-loaded composite nanofiber membranes

• Wei Fang,
• Liang Yu and
• Lan Xu

Beilstein J. Nanotechnol. 2020, 11, 631–650, doi:10.3762/bjnano.11.50

• microstructure. As given in Table 4, the content of CuO and ZnO sheets is higher in the sample in Figure 20a than in the sample in Figure 20b, resulting in a darker appearance of the CNFMs. In addition, in Figure 20a, the ratio between Cu and Zn is 3:2, which might be caused CuO crystals growing faster than ZnO

Soybean-derived blue photoluminescent carbon dots

• Shanshan Wang,
• Wei Sun,
• Dong-sheng Yang and
• Fuqian Yang

Beilstein J. Nanotechnol. 2020, 11, 606–619, doi:10.3762/bjnano.11.48

• of the HTC-processed carbon particles in the range of 250 to 850 °C causes a loss of the photoluminescent characteristics of the CDs without any significant change in the microstructure (amorphous structure) of the carbon particles. The LA processing of the annealed HTC-processed carbon particles

• at 110 °C under a compressive stress of 6000 psi for 5 min. The laser ablation of the Teflon pellet was conducted in a container with 3 mL of NH4OH for 1 h. Materials characterization The morphology and microstructure of the prepared carbon nanoparticles were characterized on a transmission electron

• change in the microstructure (amorphous structure) of carbon nanoparticles, suggesting that annealing did not likely cause any significant changes to the domain sizes in the HTC-CDs. Note that the annealing did cause the change in the size distribution of the carbon nanoparticles, as revealed in Figure

Synthesis and enhanced photocatalytic performance of 0D/2D CuO/tourmaline composite photocatalysts

• Changqiang Yu,
• Min Wen,
• Zhen Tong,
• Shuhua Li,
• Yanhong Yin,
• Xianbin Liu,
• Yesheng Li,
• Tongxiang Liang,
• Ziping Wu and
• Dionysios D. Dionysiou

Beilstein J. Nanotechnol. 2020, 11, 407–416, doi:10.3762/bjnano.11.31

• way to promote the photocatalytic activity of CuO by coupling with the polar mineral tourmaline, and provides an ideal example for the development of easily synthesized and low-cost tourmaline-based photocatalysts. The morphology, microstructure, pore structure, optical properties, and durability of

• scanning electron microscope (SEM, Tescan, Czech) was used to observe the morphology. A Titan G2 60-300 transmission electron microscope (TEM, FEI, USA) was employed to analyze the microstructure. A NEXUS 670 spectrometer (Thermo Nicolet, USA) was employed for recording the Fourier transform infrared (FTIR

• [30]. In addition, the O–H stretching vibration band of the absorbed water appeared at 3381 cm−1 [31]. SEM and TEM were carried out to characterize the morphology and microstructure of the samples. Tourmaline displayed a granular morphology with diameter of 0.1–1.0 μm (Figure 3a and 3d). The pure CuO

An advanced structural characterization of templated meso-macroporous carbon monoliths by small- and wide-angle scattering techniques

• Felix M. Badaczewski,
• Marc O. Loeh,
• Torben Pfaff,
• Dirk Wallacher,
• Daniel Clemens and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2020, 11, 310–322, doi:10.3762/bjnano.11.23

• , prepared by hard-templating of meso-macroporous SiO2 monoliths, to the corresponding nanoscale polyaromatic microstructure using two different carbon precursors wthat generally exhibit markedly different carbonization properties, i.e., a graphitizable pitch and a non-graphitizable resin. The micro- and

• physisorption was applied, using deuterated p-xylene (DPX) as a contrast-matching agent in the neutron scattering process. The impact of the carbon precursor on the structural order on an atomic scale in terms of size and disorder of the carbon microstructure, on the nanopore structure, and on the template

• process is analyzed by special evaluation approaches for SANS and wide-angle X-ray scattering (WAXS). The WAXS analysis shows that the pitch-based monolithic material exhibits a more ordered microstructure consisting of larger graphene stacks and similar graphene layer sizes compared to the monolithic

An investigation on the drag reduction performance of bioinspired pipeline surfaces with transverse microgrooves

• Weili Liu,
• Hongjian Ni,
• Peng Wang and
• Yi Zhou

Beilstein J. Nanotechnol. 2020, 11, 24–40, doi:10.3762/bjnano.11.3

• microstructure, it can be divided into streamwise grooves and transverse grooves. With the development of numerical simulations and experimental techniques, the influence of microstructures on turbulent flow characteristics can be investigated accurately. Its drag reduction mechanism is owed to the two aspects

Label-free highly sensitive probe detection with novel hierarchical SERS substrates fabricated by nanoindentation and chemical reaction methods

• Jingran Zhang,
• Tianqi Jia,
• Yongda Yan,
• Li Wang,
• Peng Miao,
• Yimin Han,
• Xinming Zhang,
• Guangfeng Shi,
• Yanquan Geng,
• Zhankun Weng,
• Daniel Laipple and
• Zuobin Wang

Beilstein J. Nanotechnol. 2019, 10, 2483–2496, doi:10.3762/bjnano.10.239

• nanoparticles are formed in the internal cavities and pile-ups of cavities. Raman spectroscopy of the hierarchical Ag/Cu substrates Microstructure optimization with different machining parameters The AgNO3 solution corrosion time and different machining parameters have a significant influence on the performance

Dynamics of superparamagnetic nanoparticles in viscous liquids in rotating magnetic fields

• Nikolai A. Usov,
• Ruslan A. Rytov and
• Vasiliy A. Bautin

Beilstein J. Nanotechnol. 2019, 10, 2294–2303, doi:10.3762/bjnano.10.221

• [46][47] or fluids with microstructure [48] that have received great attention recently due to their unique magnetohydrodynamic and heat-conduction properties. In this paper we consider the limit of a dilute assembly of magnetic nanoparticles in a liquid, which is of particular interest and

Ultrathin Ni_1−xCo_xS₂ nanoflakes as high energy density electrode materials for asymmetric supercapacitors

• Xiaoxiang Wang,
• Teng Wang,
• Rusen Zhou,
• Lijuan Fan,
• Shengli Zhang,
• Feng Yu,
• Tuquabo Tesfamichael,
• Liwei Su and
• Hongxia Wang

Beilstein J. Nanotechnol. 2019, 10, 2207–2216, doi:10.3762/bjnano.10.213

• structure of the precursor Ni1.7Co1.3O4 (Supporting Information File 1, Figure S2b–d) is maintained through this facile calcination method. Similarly, Ni1.7Co1.3O4 inherits the overall morphology of pristine NiCo-LDHs [19], which proves the microstructure was maintained during the calcination process

Oblique angle deposition of nickel thin films by high-power impulse magnetron sputtering

• Hamidreza Hajihoseini,
• Movaffaq Kateb,
• Snorri Þorgeir Ingvarsson and
• Jon Tomas Gudmundsson

Beilstein J. Nanotechnol. 2019, 10, 1914–1921, doi:10.3762/bjnano.10.186

• -based shape memory alloy thin films utilized in micro-actuator applications [9]. It is well known that microstructure, texture and structure of thin films can have significant influence on the magnetic and other functional properties of the films. The magnetic properties of evaporated [10][11

• deposition flux (i.e., using HiPIMS in GLAD), the angular distribution of the deposited material can be influenced [40][41][42]. Earlier we have explored the microstructure and magnetic properties of polycrystalline [43] and epitaxially [44] deposited permalloy (Ni80Fe20 atom %) thin films deposited under 35

• higher tilt angles includes greater uncertainty. The measured and simulated XRR data are presented in Figure 2 for depositions under tilt angles of 0° and 70°. To investigate the microstructure of our Ni films, GiXRD analysis was carried out. Figure 3 exhibits a GiXRD pattern of a dcMS-deposited Ni film