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

• an electric eel, called nanoeel. It has a smart flexible tail, made of polyvinylidene fluoride copolymer, connected to the head of a polypyrrole nanowire. The head is decorated with a nickel ring for magnetic actuation. When an alternating magnetic field is applied, the magnetic head module (nickel

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

• operating frequency range. Targeted treatment and controlled drug delivery with MNRs have been achieved [74][75]. For locomotion and drug delivery, the same external power sources should be chosen, if possible. Chen et al. [76] proposed a hybrid magnetoelectric nanowire for MNR applications, which could use

• materials. In the presence of an external magnetic field, a piezoresponse force microscope (PFM) could be used to directly probe the ferroelectricity and magnetoelectricity of this nanowire. Experiments were carried out in a specially designed setup with three pairs of orthogonal electromagnetic coils to

Nanogenerator-based self-powered sensors for data collection

• Yicheng Shao,
• Maoliang Shen,
• Yuankai Zhou,
• Xin Cui,
• Lijie Li and
• Yan Zhang

Beilstein J. Nanotechnol. 2021, 12, 680–693, doi:10.3762/bjnano.12.54

• . Lee et al. proposed a based Hg2+ ion sensor based on ZnO nanowires and carbon nanotubes for detecting toxic pollutants [17]. The ZnO nanowire (NW) array acted as power source. When Hg2+ ions were detected, the system powered a light-emitting diode (LED). Li et al. designed a self-powered heavy metal

• to the test gas. The sensitivity of above ZnO-based self-powered sensor is 127.3% under 1000 ppm H2S. The piezoelectric output of sensor decreased with increase of the concentration of the tested gas, as shown in Figure 5e. In 2016, a self-powered gas sensor based on a NiO/ZnO heterojunction nanowire

• flexible nanogenerator as self-powered sensor for transportation monitoring“, pages no. 75–81, Copyright (2012), with permission from Elsevier. Figure 1f was republished from [18] (X. Xue et al., “Surface free-carrier screening effect on the output of a ZnO nanowire nanogenerator and its potential as a

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

• into the YBCO thin film and thus be used to define precise sample geometries, without material removal. For example, high-dose irradiation over larger areas leaving a narrow gap in between has been used to define YBCO nanowires, which were then line-irradiated at lower dose to form nanowire-based

• membrane targets by ion implantation. Ion-induced mass transport In one example of a morphological change attributed to ion-induced mass transport, segments of a free-standing GaAs nanowire of 100 nm diameter were irradiated locally with 30 keV helium ions at relatively low dose resulting in local thinning

• the beam energy and current, the growth of single-crystal nanowires was also shown. This is reminiscent of nanowire growth by the vapor–solid–liquid mechanism, except here the process was performed at room temperature and without the flow of a gaseous precursor. In the HIM case it was proposed that

High-yield synthesis of silver nanowires for transparent conducting PET films

• Gul Naz,
• Hafsa Asghar,
• Muhammad Ramzan,
• Muhammad Arshad,
• Rashid Ahmed,
• Muhammad Bilal Tahir,
• Bakhtiar Ul Haq,
• Nadeem Baig and
• Junaid Jalil

Beilstein J. Nanotechnol. 2021, 12, 624–632, doi:10.3762/bjnano.12.51

• synthesis, ethylene glycol was used as a reducing agent in the presence of PVP as capping agent. Silver nitrate and CuCl2 were used as sources of silver and metallic salt, respectively. The resultant nanowires grew 3.3–4.7 µm in length and 75–97 nm in diameter. A silver nanowire ink was then transferred to

• nanowire interactions. Also, the aligned assembly may not only yield reduced PET film roughness and resistance but also improved transmissivity. Here, AgNWs with lengths and diameters of 3.3–4.7 µm and 75–97 nm, respectively, have been formed in the reaction. The AgNWs with larger diameters yield lower

• free from impurities, that is, silver nanoparticles. No other nanostructures could affect the optical and conduction properties, or the roughness of the film. A silver nanowire ink formulated by adding HEC to an aqueous solution of silver nanowires, was then loaded onto the surface of PET films by

Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects

• Jakub Kierdaszuk,
• Piotr Kaźmierczak,
• Justyna Grzonka,
• Aleksandra Krajewska,
• Aleksandra Przewłoka,
• Wawrzyniec Kaszub,
• Zbigniew R. Zytkiewicz,
• Marta Sobanska,
• Maria Kamińska,
• Andrzej Wysmołek and
• Aneta Drabińska

Beilstein J. Nanotechnol. 2021, 12, 566–577, doi:10.3762/bjnano.12.47

• different nanowire substrates shows that bigger differences in nanowires height increase graphene strain, while a higher number of nanowires in contact with graphene locally reduces the strain. Moreover, the value of graphene carrier concentration is found to be correlated with the density of nanowires in

• graphene on rarely distributed nanowires. Our results also show modification of graphene carrier concentration and strain by different types of defects present in graphene. Therefore, the nanowire substrate is promising not only for strain and carrier concentration engineering but also for defect

• absorption [9]. However, the interaction between corrugated nanowire substrate and graphene could substantially increase the scattering of carriers in a graphene electrode and decrease its conductivity. Therefore, detailed studies of the interaction between nanowire substrate and graphene are crucial to gain

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

• start to elongate rapidly and their width approaches the optimal value of s ≃ 80 nm (Figure 7a). We have calculated an island aspect ratio as large as t/s ≃ 17 in our sample. These results confirm the compatibility of the nanowire growth with the strain-induced elongation mechanism, also observed in

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

• Sina Kaabipour and
• Shohreh Hemmati

Beilstein J. Nanotechnol. 2021, 12, 102–136, doi:10.3762/bjnano.12.9

Piezotronic effect in AlGaN/AlN/GaN heterojunction nanowires used as a flexible strain sensor

• Jianqi Dong,
• Liang Chen,
• Yuqing Yang and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1847–1853, doi:10.3762/bjnano.11.166

• heterojunction (left panel, b1) and HRTEM image of the corresponding GaN layer (right panel, b2). (c) XRD 2θ scan of the epitaxial structure in the region of the (002) reflection. (a) Schematic diagrams after ICP dry etching, (b) during EC wet etching, (c) and of a single nanowire. (d) SEM image of a AlGaN/AlN

Seebeck coefficient of silicon nanowire forests doped by thermal diffusion

• Shaimaa Elyamny,
• Elisabetta Dimaggio and
• Giovanni Pennelli

Beilstein J. Nanotechnol. 2020, 11, 1707–1713, doi:10.3762/bjnano.11.153

• Technological Applications (SRTA-City), New Borg El-Arab City, 21934, Alexandria, Egypt 10.3762/bjnano.11.153 Abstract Thermoelectric generators made by large arrays of nanowires perpendicular to a silicon substrate, that is, so-called silicon nanowire forests are fabricated on large areas by an inexpensive

• metal-assisted etching technique. After fabrication, a thermal diffusion process is used for doping the nanowire forest with phosphorous. A suitable experimental technique has been developed for the measurement of the Seebeck coefficient under static conditions, and results are reported for different

• doping parameters. These results are in good agreement with numerical simulations of the doping process applied to silicon nanowires. These devices, based on doped nanowire forests, offer a possible route for the exploitation of the high power factor of silicon, which, combined with the very low thermal

Piezoelectric sensor based on graphene-doped PVDF nanofibers for sign language translation

• Shuai Yang,
• Xiaojing Cui,
• Rui Guo,
• Zhiyi Zhang,
• Shengbo Sang and
• Hulin Zhang

Beilstein J. Nanotechnol. 2020, 11, 1655–1662, doi:10.3762/bjnano.11.148

• is added under stirring to yield the spinning solution for electrospinning. After preparation of the fibers, an aqueous solution of Ti3C2 MXene and Ag NWs is sprayed on both sides of the material and then dried. Finally, the nanowire membrane is covered on both sides with PDMS to obtain the

A self-powered, flexible ultra-thin Si/ZnO nanowire photodetector as full-spectrum optical sensor and pyroelectric nanogenerator

• Liang Chen,
• Jianqi Dong,
• Miao He and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1623–1630, doi:10.3762/bjnano.11.145

• work, a new type of self-powered, high-performance ultra-thin p-Si/n-ZnO nanowire (NW) flexible photodetector (PD) and its application as full-spectrum optical sensor and pyroelectric nanogenerator (PENG) are demonstrated. The working mechanism of PDs for PENGs is carefully investigated and

Walking energy harvesting and self-powered tracking system based on triboelectric nanogenerators

• Mingliang Yao,
• Guangzhong Xie,
• Qichen Gong and
• Yuanjie Su

Beilstein J. Nanotechnol. 2020, 11, 1590–1595, doi:10.3762/bjnano.11.141

• inductively coupled plasma chamber, at corresponding flow rates of 10.0, 30.0, and 15.0 sccm, respectively. The nanowire structure was obtained on the surface by etching the PTFE film for 15 s. The high-density plasma was generated by a 500 W power source while the plasma ions were triggered by another 160 W

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• random structures are typically vertically aligned nanowires, also called nanorods. Silicon nanowire arrays can be designed to have a low reflectance of about 1% in a broad spectral range, depending on their geometry. These silicon structures exhibit efficient light trapping because photons are scattered

• to fabricate high-efficiency solar cells [4][5]. These nanowire-based solar cells show a higher short circuit current and a higher quantum efficiency than planar cells [6]. Another energy conversion application for nanowires is a thermoelectric harvester. The one-dimensional structures reduce heat

• transport and improve the efficiency of the thermoelectric generator [7]. Silicon nanowire arrays are also an emerging anode material for integrated lithium-ion batteries. They have a ten times higher theoretical capacity than graphite and can be used for cells with high energy density. However, these

Superconductor–insulator transition in capacitively coupled superconducting nanowires

• Alex Latyshev,
• Andrew G. Semenov and
• Andrei D. Zaikin

Beilstein J. Nanotechnol. 2020, 11, 1402–1408, doi:10.3762/bjnano.11.124

• voltage in the form of pulses. By applying a bias current the symmetry between positive and negative voltage pulses is broken and, as a result, a superconducting nanowire acquires a non-vanishing electrical resistance down to the lowest temperatures [5][6]. This effect was directly observed in a number of

• those of another one, thereby shifting the QPT in each of the wires in a way to increase the parameter range for the insulating phase. Qualitatively the same effect is expected to occur in a single superconducting nanowire that has the form of a meander frequently used in experiments. Results and

• properties can be investigated in exactly the same manner as was done in [5] in the case of a single nanowire. Generalization of the technique [5] to the case of two capacitively coupled superconducting nanowires is straightforward. For a linear resistance of the ith wire Ri(T) and for λii > 2 (or for any

Analysis of catalyst surface wetting: the early stage of epitaxial germanium nanowire growth

• Owen C. Ernst,
• Felix Lange,
• David Uebel,
• Thomas Teubner and
• Torsten Boeck

Beilstein J. Nanotechnol. 2020, 11, 1371–1380, doi:10.3762/bjnano.11.121

• grow germanium nanowires on different substrates is described. Keywords: dewetting; germanium; interfacial energy; Laplace pressure; nanostructure; nanowire; Ostwald ripening; wetting layer; Introduction Wetting phenomena as well as the formation and movement of droplets are essential for numerous

• can be found in the Experimental section. The resulting free energy leads to different nanodroplets, which changed their catalytic behaviour during nanowire growth. Results and Discussion Theoretical results Gold on silicon oxide Figure 1 shows the first derivative of the free energy with respect to

• germanium was deposited onto Au/Si substrates, germanium nanowires were grown. The in-plane nanowires started to grow at places where the gold droplets had formed previously. The inset shows gold at the top of the germanium nanowire, where continuous homoepitaxial growth was catalysed. A sample with a

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

• is present along the whole nanowire length. Moreover, these nanowires become superconducting at 6.8 K and show high values of critical magnetic field and critical current density. Consequently, these 3D nano-objects could be implemented as components in the next generation of electronics, such as

• ion beam current from 1.3 to 7 pA. STEM images of these hollow NWs are shown in Figure 3a. The observed non-uniform shape of the cavity in the central nanowire could be explained by several reasons, such as He+ FIB instability or irregular substrate surface. We find a linear dependence of the inner

Revealing the local crystallinity of single silicon core–shell nanowires using tip-enhanced Raman spectroscopy

• Marius van den Berg,
• Ardeshir Moeinian,
• Arne Kobald,
• Yu-Ting Chen,
• Anke Horneber,
• Steffen Strehle,
• Alfred J. Meixner and
• Dai Zhang

Beilstein J. Nanotechnol. 2020, 11, 1147–1156, doi:10.3762/bjnano.11.99

• electronic functionality of such nanometer-scale building blocks. A rational and well-established synthesis strategy for the creation of complex silicon nanostructures is metal-catalyzed vapor–liquid–solid (VLS) nanowire growth [13]. VLS nanowire growth belongs to the gas-phase synthesis procedures, similar

• to chemical vapor deposition (CVD), and enables direct nanowire growth in a bottom-up manner. The nanowire composition, in particular the doping concentration, can be controlled by an adequate adjustment of the synthesis gas mixture, e.g., by setting the SiH4/B2H6 ratio during the synthesis of boron

• the optical and electronic behavior of nanowire building blocks. Hence, there is an inherent need for non-destructive characterization techniques that are able to elucidate the local crystallinity. Raman spectroscopy is such a type of non-destructive characterization techniques and has become a

Electrochemical nanostructuring of (111) oriented GaAs crystals: from porous structures to nanowires

• Elena I. Monaico,
• Eduard V. Monaico,
• Veaceslav V. Ursaki,
• Shashank Honnali,
• Vitalie Postolache,
• Karin Leistner,
• Kornelius Nielsch and
• Ion M. Tiginyanu

Beilstein J. Nanotechnol. 2020, 11, 966–975, doi:10.3762/bjnano.11.81

• present work also exhibit a diameter distribution with a certain width. However, we believe that the distribution could be narrowed by further optimization of the technological processes. Note that the diameter of a particular nanowire is determined by the width of the space charge region (SCR) set up

• metal deposition. Note that the nanowire was visible in the optical microscope due to its length of 70 µm, despite the small diameter. The distance between the contacts is 20 µm. A photograph of five contacted nanowires on a glass substrate after Cr/Au deposition and lift-off is presented in the inset

• of the Figure 7A. The photocurrent build-up and relaxation for a photodetector produced on a nanowire with a diameter of 400 nm is presented in Figure 7B for an IR illumination density of 800 mW·cm−2. One can see that the current increases by a factor of four in magnitude under illumination with IR

Transition from freestanding SnO₂ nanowires to laterally aligned nanowires with a simulation-based experimental design

• Jasmin-Clara Bürger,
• Sebastian Gutsch and
• Margit Zacharias

Beilstein J. Nanotechnol. 2020, 11, 843–853, doi:10.3762/bjnano.11.69

• experiments in order to switch freestanding nanowire growth to a laterally aligned growth mode. By means of finite element simulations, we determined that a higher volumetric flow and a reduced process pressure will result in a preferred laterally aligned nanowire growth. Furthermore, increasing the

• Sn gas was achieved by a carbothermal reduction of SnO2 powder. However, we observed no elongation of the nanowire length with an increase of the process time. Nevertheless, an alternating gas exchange between an inert gas (Ar) and an oxygen-containing process atmosphere yielded an elongation of the

• laterally aligned nanowires, indicating that the nanowire growth takes place in a transient period of the gas exchange. Keywords: finite element method simulation; laterally aligned nanowires; planar growth; tin oxide; vapor–liquid–solid nanowire growth; Introduction Since the first reports in 1964 by

Electromigration-induced directional steps towards the formation of single atomic Ag contacts

• Atasi Chatterjee,
• Christoph Tegenkamp and
• Herbert Pfnür

Beilstein J. Nanotechnol. 2020, 11, 680–687, doi:10.3762/bjnano.11.55

• corresponds to characteristic decrements of conductance. It can be interpreted by the semi-classical Sharvin formula. This formula is an approximation for contacts approaching the ballistic regime. Within this model, the nanowire conductance for a circular cross-sectional area, A, is given by [21]: with the

High-performance asymmetric supercapacitor made of NiMoO₄ nanorods@Co₃O₄ on a cellulose-based carbon aerogel

• Meixia Wang,
• Jing Zhang,
• Xibin Yi,
• Benxue Liu,
• Xinfu Zhao and
• Xiaochan Liu

Beilstein J. Nanotechnol. 2020, 11, 240–251, doi:10.3762/bjnano.11.18

• construction of an integrated hierarchical porous nanoarchitecture by combining two metal oxides is a brilliant way to greatly enhance the overall electrochemical performance owing to synergistic effects [20]. For example, Li et al. synthesized 3D hybrid Co3O4/NiMoO4 nanowire/nanosheet arrays on a carbon cloth

• , which exhibited a capacitance of 3.6 F/cm2 at 3 mA/cm2, a capacitance retention of 82% and an increase of the current density from 3 to 15 mA/cm2 [21]. Cai et al. reported a facile two-step hydrothermal method to synthesize unique 3D Co3O4/NiMoO4 core/shell nanowire arrays on Ni foam, and the resulting

Molecular architectonics of DNA for functional nanoarchitectures

• Debasis Ghosh,
• Lakshmi P. Datta and
• Thimmaiah Govindaraju

Beilstein J. Nanotechnol. 2020, 11, 124–140, doi:10.3762/bjnano.11.11

• template for nanowire synthesis. The miniaturization of devices is of central importance in electronics and has galvanized significant research in materials science. The need for the miniaturization of devices at the nanoscale interface has led to the exploration of new material systems and building blocks

Abrupt elastic-to-plastic transition in pentagonal nanowires under bending

• Sergei Vlassov,
• Magnus Mets,
• Boris Polyakov,
• Jianjun Bian,
• Leonid Dorogin and
• Vahur Zadin

Beilstein J. Nanotechnol. 2019, 10, 2468–2476, doi:10.3762/bjnano.10.237

• are described by the widely used embedded atom method (EAM), and a potential for Ag is utilized here [36]. Due to the limitation of computational resources, the size of the nanowire in simulation is much smaller than that in the experiments. Figure 2a shows the atomic configuration of the penta

• showed that coating can increase the bending strength of the NWs. Schematic and SEM image of a pentagonal silver nanowire (Ag NW). SEM image adapted with permission from [28], copyright 2013 Elsevier. (a) Atomic simulation model of the Ag NW, (b) the internal twin structures (atoms in perfect lattice and

Deterministic placement of ultra-bright near-infrared color centers in arrays of silicon carbide micropillars

• Stefania Castelletto,
• Abdul Salam Al Atem,
• Faraz Ahmed Inam,
• Hans Jürgen von Bardeleben,
• Sophie Hameau,
• Ahmed Fahad Almutairi,
• Gérard Guillot,
• Shin-ichiro Sato,
• Alberto Boretti and
• Jean Marie Bluet

Beilstein J. Nanotechnol. 2019, 10, 2383–2395, doi:10.3762/bjnano.10.229

• nanowire detector with 80% quantum efficiency, and the DWF is 5%. The ZFS is 1.2–1.4 GHz in the ground state and 0.75–0.95 GHz in excited states. Both VSi and VSiVC have been proved to be useful for a high-fidelity spin–photon interface [6][27]. PL spectroscopy and EPR measurements combined with ab initio