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

• performance of magnetic micro- and nanorobots in microbial environments, some future challenges are outlined, and the prospects of magnetic applications for micro- and nanorobots are presented. Keywords: magnetic drives; magnetic nanoparticles; magnetoelectric devices; micro- and nanorobots; Introduction

• , it is necessary to advance from multiple angles at the same time and improve energy transmission efficiency while also improving other aspects of performance as much as possible. For magnetic MNRs, a specific magnetic drive structure is required. For example, a MNR with conical spiral structures

• could be efficiently processed by modulated structured light. The MNR with this structure had a stronger surge performance and the ability to load cargo. Magnetically responsive materials were added to the surface of a MNR with a structure of a hollow helical conically shaped tube. A custom-built three

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

• generally contribute to the attachment on rough surfaces due to friction and mechanical interlocking [83][89][92][232][233][234][235][236]. The performance of claws depends on the radius of the claw tip in relation to the curvature of the surface irregularities [83][234][237][238]. However, in combination

Prediction of Co and Ru nanocluster morphology on 2D MoS₂ from interaction energies

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2021, 12, 704–724, doi:10.3762/bjnano.12.56

• or doping with transition metals [4][5][18][19][20][21][22], alkali and alkali earth metals [23][24][25], and non-metals [25] on MoS2 and other 2D materials. While experimental studies can be used to probe the performance of the 2D material in a device or some of the interfacial interactions between

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

• novel data source for big data and AI. Especially, TENGs are good candidates for designing AI sensors [66]. TENGs can be used as an energy source for traditional sensors to collect tiny amounts of energy from the environment, such as from liquid droplets [67]. The performance of TENGs can be improved

• intelligence. Wang et al. proposed a hydrophobic polytetrafluoroethylene film and sponge-like graphene/polydimethylsiloxane composite material to prepare a multifunctional self-powered sensor [51]. The sensor can infer the performance of the material through the difference in the output of the electrical

• during human exercise to generate electricity, and its output performance is affected by the concentration of lactic acid in the sweat, as shown in Figure 4d. According to the change of output voltage data, big data analysis can be performed on the exercise status of the athlete. Training status and

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

• study, field-effect transistors based on monolayer MoS2 were irradiated with helium ions over the transistor channel and the effect of varying the size and position of the irradiated area on the electrical performance of the device was characterized [28]. Complimentary work on few-layer WSe2 by Stanford

• structures [45]. The performance of Josephson junctions in YBCO thin films fabricated using the HIM has been further evaluated in [46]. Cross-sectional STEM analysis of helium line irradiations of YBCO has shown that the crystallinity of the Josephson junction barriers is essentially preserved, highlighting

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

• performance below that of ITO films. Hence, there is a need to modify this polyol method to produce extra-large and highly ordered silver nanowires to outperform ITO films. It is important to note that the polyol synthesis yields impurities in the form of silver nanoparticles [29]. These nanoparticles formed

• original sheet resistance value after 500 bend–release cycles, thus exhibiting a stable electrical performance. The study describes a simple, inexpensive, eco-friendly and non-toxic method to prepare flexible transparent conducting films that could prove very beneficial for flexible transparent

Nanoporous and nonporous conjugated donor–acceptor polymer semiconductors for photocatalytic hydrogen production

• Zhao-Qi Sheng,
• Yu-Qin Xing,
• Yan Chen,
• Guang Zhang,
• Shi-Yong Liu and
• Long Chen

Beilstein J. Nanotechnol. 2021, 12, 607–623, doi:10.3762/bjnano.12.50

• be easily tuned via structural design. In addition, they are of light weight (i.e., mainly composed of C, N, O, and S). To improve the photocatalytic performance of CPs and better understand the catalytic mechanisms, many strategies with respect to material design have been proposed. These include

• tuning the bandgap, enlarging the surface area, enabling more efficient separation of electron–hole pairs, and enhancing the charge carrier mobility. In particular, donor–acceptor (D–A) polymers were demonstrated as a promising platform to develop high-performance photocatalysts due to their easily

• , for example, La, Bi, and Ta, which are often rare, toxic, and expensive [6]. Also, expensive noble metal-based cocatalysts (e.g., Pt) are required to improve the photocatalytic performance. As such, an ideal photocatalyst for water splitting reaction should fit the following criteria: suitable bandgap

Impact of GaAs(100) surface preparation on EQE of AZO/Al₂O₃/p-GaAs photovoltaic structures

• Piotr Caban,
• Rafał Pietruszka,
• Jarosław Kaszewski,
• Monika Ożga,
• Bartłomiej S. Witkowski,
• Krzysztof Kopalko,
• Piotr Kuźmiuk,
• Katarzyna Gwóźdź,
• Ewa Płaczek-Popko,
• Krystyna Lawniczak-Jablonska and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 578–592, doi:10.3762/bjnano.12.48

• [3]. Due preparation of the substrate, seems to be one of the most important aspects here as the oxide-based states of the GaAs surface are known to adversely affect device performance. Thus, in this present work we focus on the methods to limit their role. Reactivity of the surface of gallium

• negative impact on the performance of GaAs-based microelectronic and optoelectronic devices [10][11]. Therefore, in order to take advantage of the properties of gallium arsenide [12], its interface with a dielectric or other semiconductor partner must be carefully prepared. This can be obtained either by

• . Lesker PVD75). It should also be underscored that the utilized structure was quite simplified and not optimized for the best performance in terms of junction properties, absorber and window layers, doping/thickness, or metallization used. Measurement equipment The morphology of the structures was

On the stability of microwave-fabricated SERS substrates – chemical and morphological considerations

• Limin Wang,
• Aisha Adebola Womiloju,
• Christiane Höppener,
• Ulrich S. Schubert and
• Stephanie Hoeppener

Beilstein J. Nanotechnol. 2021, 12, 541–551, doi:10.3762/bjnano.12.44

• on the SERS activity of the substrates and a carbonate buffer at pH 10 was found to even improve SERS performance. This study represents a guideline on the stability of microwave-fabricated SERS substrates or other SERS substrates consisting of non-stabilized silver nanoparticles for the application

• Raman signals can be significantly improved when the measurements are performed on roughened silver electrodes [5], an understanding of the SERS enhancement process has been gained from a large number of investigations. This has rationalized the requirements for a good performance of SERS substrates

• gaps which can particularly enhance the Raman intensities. Consequently, a lot of research and development efforts have been devoted to the fabrication of high-performance substrates following a wide range of different design concepts. These include, for example, the assembly of colloidal nanoparticles

Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride

• Malgorzata Aleksandrzak,
• Michalina Kijaczko,
• Wojciech Kukulka,
• Daria Baranowska,
• Martyna Baca,
• Beata Zielinska and
• Ewa Mijowska

Beilstein J. Nanotechnol. 2021, 12, 473–484, doi:10.3762/bjnano.12.38

• photocatalytic activity [15][16][17]. Furthermore, it exhibits high thermal and chemical stability during photocatalytic reactions in the aqueous phase [18]. Unfortunately, its catalytic performance is mainly constrained by several typical challenges, which are the low density of reactive sites, nonresponse in

• three cycles of light on–off, the performance of both electrodes tends to stabilize, indicating that the photocatalysts are stable under visible-light irradiation [55]. The measurements obtained from electrochemical impedance spectroscopy (EIS) are shown in Figure 9b. It is known that the arc radius of

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

• . Most of the reported Au–Pt bimetal nanoparticles are isotropic, such as alloys or core–shell structures [18][19][20]. However, the LSPR peaks of such alloys or core–shell structures are located in the visible light region and inhibit the plasma performance [21]. Significant efforts have been made to

• photothermal stability. Our work has paved the way for the controllable synthesis of Au@Pt NRs with specific optical properties and stable photothermal performance. The Au@Pt NRs are capable of acting as a novel PTAs and show good application prospects in the photothermal therapy of tumors. Experimental

Solution combustion synthesis of a nanometer-scale Co₃O₄ anode material for Li-ion batteries

• Monika Michalska,
• Huajun Xu,
• Qingmin Shan,
• Shiqiang Zhang,
• Yohan Dall'Agnese,
• Yu Gao,
• Amrita Jain and
• Marcin Krajewski

Beilstein J. Nanotechnol. 2021, 12, 424–431, doi:10.3762/bjnano.12.34

• been established that the electrochemical performance of Co3O4 materials is improved when they possess either small size or appropriate pore size distribution and morphologies, such as porous or hierarchical structures, or the combination of both these features [3][4]. So far, different syntheses have

• compact structure rather than a porous one (Figure 2c). The electrochemical performance of the Co3O4 powder as anode material was evaluated in a two-electrode coin cell in a voltage window from 0.01 to 3.0 V vs Li+/Li. The first to fifth charge–discharge cycle profiles measured at a current density of 100

• powder magnified (a) 25,000 times and (b) 100,000 times. (c) TEM image of the Co3O4 powder (inset: a particle size distribution diagram). Electrochemical properties of the Co3O4 electrodes. (a) The first to fifth cycle profiles measured at current density of 100 mA·g−1. (b) Cycling performance measured

A stretchable triboelectric nanogenerator made of silver-coated glass microspheres for human motion energy harvesting and self-powered sensing applications

• Hui Li,
• Yaju Zhang,
• Yonghui Wu,
• Hui Zhao,
• Weichao Wang,
• Xu He and
• Haiwu Zheng

Beilstein J. Nanotechnol. 2021, 12, 402–412, doi:10.3762/bjnano.12.32

• sustainable electricity. However, there is a need for improvement regarding the output performance and the complex fabrication of TENG devices. Here, a triboelectric nanogenerator in single-electrode mode is fabricated by a simple strategy, which involves a sandwich structure of silicone rubber and silver

• -coated glass microspheres (S-TENG). The S-TENG exhibits a remarkable performance in harvesting human motion energy and as flexible tactile sensor. By optimizing the device parameters and operating conditions, the maximum open-circuit voltage and short-circuit current of the S-TENG can reach up to 370 V

• harvesting human motion energy and monitoring [17]. It can produce an open-circuit voltage up to 150 V and an optimal instantaneous power density of 44.6 mW/m2. From the abovementioned references [15][16], it can be seen that the output performance remains to be improved despite the complex fabrication

The impact of molecular tumor profiling on the design strategies for targeting myeloid leukemia and EGFR/CD44-positive solid tumors

• Nikola Geskovski,
• Nadica Matevska-Geshkovska,
• Simona Dimchevska Sazdovska,
• Marija Glavas Dodov,
• Kristina Mladenovska and
• Katerina Goracinova

Beilstein J. Nanotechnol. 2021, 12, 375–401, doi:10.3762/bjnano.12.31

Structural and optical characteristics determined by the sputtering deposition conditions of oxide thin films

• Petronela Prepelita,
• Florin Garoi and
• Valentin Craciun

Beilstein J. Nanotechnol. 2021, 12, 354–365, doi:10.3762/bjnano.12.29

• calculated from the absorption spectra. The influence of thickness on the structural and optical properties of the oxide films was investigated. Good optical quality and performance were noticed, which makes these thin films worthy of integration into metamaterial structures. Keywords: magnetron sputtering

• structural characteristics allows us to clearly point out the need to use these materials in metamaterial structures. The novelty of this study is the acquisition of high-performance structural and optical properties of oxide materials deposited by rfMS under optimized conditions. These oxide materials can

• structural performance as compared to the other films obtained under similar deposition conditions. This conclusion is supported by the increase in size of the ZnO crystallites and values of the texturing coefficient, which are greater than 1, showing that a larger number of crystallites are oriented with

Nickel nanoparticle-decorated reduced graphene oxide/WO₃ nanocomposite – a promising candidate for gas sensing

• Ilka Simon,
• Alexandr Savitsky,
• Rolf Mülhaupt,
• Vladimir Pankov and
• Christoph Janiak

Beilstein J. Nanotechnol. 2021, 12, 343–353, doi:10.3762/bjnano.12.28

• 200 to 400 °C, which means a high power consumption [4]. WO3 is a wide-bandgap [12][13] n-type semiconductor [14][15] with good sensitivity towards NO2 [16] and CO [17]. Known successful routes to improve the MOS gas sensing performance are doping with transition metals, decoration with noble metals

• performance of MOS@rGO can further be improved by either chemical doping or by combination with a transition metal as ternary component [38]. Iron oxide-doped WO3 films showed improved NO2 sensing at room temperature, when adding a layer of 16 nm p-type rGO on the metal oxide film [39]. Nickel-doped SnO2

• plays an important role in charge transfer processes and leads to the enhancement in the gas sensing performance due to the synergistic effect between rGO (p-type) WO3 (n-type) [29]. In [37][53], the formation of C–O–W bonds at the interphase boundaries was observed, when studying a rGO/WO3 composite

Intracranial recording in patients with aphasia using nanomaterial-based flexible electronics: promises and challenges

• Qingchun Wang and
• Wai Ting Siok

Beilstein J. Nanotechnol. 2021, 12, 330–342, doi:10.3762/bjnano.12.27

• include maps of human brain function that reveal brain regions involved in the performance of a particular cognitive task. PET and fMRI have good spatial resolution and are useful for localising functional brain activation but have poor temporal resolution. In contrast, EEG has good temporal resolution

The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication

• Victor Deinhart,
• Lisa-Marie Kern,
• Jan N. Kirchhof,
• Sabrina Juergensen,
• Joris Sturm,
• Enno Krauss,
• Thorsten Feichtner,
• Sviatoslav Kovalchuk,
• Michael Schneider,
• Dieter Engel,
• Bastian Pfau,
• Bert Hecht,
• Kirill I. Bolotin,
• Stephanie Reich and
• Katja Höflich

Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25

• performance [47][48]. Furthermore, the material removal reduces the thermal coupling of the central device area to the supporting substrate. As graphene is a single-atomic layer, it exhibits the lowest possible heat capacity per unit area of the material [48]. Its broadband spectral absorbance [49], in

• provides the necessary functionalities to unlock the ultimate performance of He ion microscopy. FIB-o-mat overview. (a) For patterning the beam spot follows a rasterized beam path with a defined pitch and dwell time per spot. The piece-wise continuous beam path could be generated from a curved shape (lime

Gold(I) N-heterocyclic carbene precursors for focused electron beam-induced deposition

• Cristiano Glessi,
• Aya Mahgoub,
• Cornelis W. Hagen and
• Mats Tilset

Beilstein J. Nanotechnol. 2021, 12, 257–269, doi:10.3762/bjnano.12.21

• as the other ancillary ligand, this has been modified in compounds 4, 5, and 7 with the introduction of a bromide, iodide, or trifluoromethyl group, respectively. The effect of the halogen substitution on the performance of FEBID precursors has, to the best of our knowledge, not been investigated yet

Scanning transmission helium ion microscopy on carbon nanomembranes

• Daniel Emmrich,
• Annalena Wolff,
• Nikolaus Meyerbröker,
• Jörg K. N. Lindner,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 222–231, doi:10.3762/bjnano.12.18

• principle is based on a secondary electron conversion holder with an exchangeable aperture strip allowing its acceptance angle to be tuned from 3 to 98 mrad. The contrast mechanism and performance were investigated using freestanding nanometer-thin carbon membranes. The results demonstrate that the detector

• the authors of the program SRIM for making the software freely available. Funding Annalena Wolff would like to thank AMAS/EMAS for the Early Career Scholarship and the QUT VC Performance Award fund, which all made the HIM World Tour 2017 and collaboration on this project possible.

Toward graphene textiles in wearable eye tracking systems for human–machine interaction

• Ata Jedari Golparvar and
• Murat Kaya Yapici

Beilstein J. Nanotechnol. 2021, 12, 180–189, doi:10.3762/bjnano.12.14

• snap” option was defined to allow for a rapid, discretized transition of the cursor from its existing location to the nearest key in the specified direction of motion. To evaluate the performance of the graphene textile-based wearable eye mouse, two different tests were carried out. In the first case

• frames along with the recorded EOG waveforms revealed a detection accuracy of approx. 98%. Only one out of 41 eye movements was misinterpreted with the developed system, demonstrating the near excellent performance of the truly wearable headband prototype for human–robot interaction and control

Paper-based triboelectric nanogenerators and their applications: a review

• Jing Han,
• Nuo Xu,
• Yuchen Liang,
• Mei Ding,
• Junyi Zhai,
• Qijun Sun and
• Zhong Lin Wang

Beilstein J. Nanotechnol. 2021, 12, 151–171, doi:10.3762/bjnano.12.12

• paper, we then highlight the strategies to improve the output performance of P-TENGs. In another section, we give a detailed review on the application of P-TENGs, with two-dimensional patterns and three-dimensional structures, on self-powered sensing devices, human–machine interaction, electrochemistry

• gradual decay of the surface charges (Figure 3-iv). Treatment methods for paper and P-TENGs The electrical properties of paper are critical determinants of the performance of P-TENGs. The original paper structure usually does not meet all the requirements for the desired applications on P-TENG devices

• electrode or into a charge-enriched friction layer to improve P-TENG output performances. As the TENG output performance closely depends on the triboelectric polarity of the friction layer, the engineering of friction layers with more charges with an opposite polarity induces a larger triboelectric charge

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

• in terms of scale-up capability, but also with respect to product quality and performance. Various green synthesis studies of Ag nanostructures are reported in Table 2 along with the reaction conditions, size and morphology of synthesized Ag nanostructures, responsible functional groups in reduction

Numerical analysis of vibration modes of a qPlus sensor with a long tip

• Kebei Chen,
• Zhenghui Liu,
• Yuchen Xie,
• Chunyu Zhang,
• Gengzhao Xu,
• Wentao Song and
• Ke Xu

Beilstein J. Nanotechnol. 2021, 12, 82–92, doi:10.3762/bjnano.12.7

• and fq in the in-phase mode (Figure 3 and Figure 6). We found a 0.05 mm tip has the best performance when the tip length is 0.65 mm in the anti-phase mode. However, Ax/Az in the anti-phase mode is 2.36, that is, φ is 23°. In frequency modulation-atomic force microscopy (FM-AFM), the frequency shift Δf

• than 1.2 mm in the in-phase mode would exhibit a better performance. Conclusion The oscillation characteristics of qPlus sensors with different dimensions of tungsten tips were studied by using the finite element method. The results reveal that the changes of the output current and the tuning fork

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• high power density as well as due to the potential to further increase the energy density. Supercapacitors may act as batteries in electrochemical performance tests. The choice of the materials, their morphology, dimension, and synthesis technique, as well the synergy with the other components of the

• used as electrode materials in storage devices, for example, supercapacitors, the device performance can be enhanced substantially. This enhancement can be correlated to materials characteristics, such as nanoscale size effects, doping, the synergy between the defective electrode and the counter

• layered thick solids and, thus, do not contain spaces for the penetration of Li ions into the electrode [15]. Therefore, to enhance the performance of MXene supercapacitors an increased ion transfer rate is needed [18][23]. MXenes exhibit two major changes due to the removal of the A layer from the