Electrostatic pull-in application in flexible devices: A review

• Teng Cai,
• Yuming Fang,
• Yingli Fang,
• Ruozhou Li,
• Ying Yu and
• Mingyang Huang

Beilstein J. Nanotechnol. 2022, 13, 390–403, doi:10.3762/bjnano.13.32

• Technology, Nanjing University of Posts and Telecommunications, Nanjing, China 10.3762/bjnano.13.32 Abstract The electrostatic pull-in effect is a common phenomenon and a key parameter in the design of microscale and nanoscale devices. Flexible electronic devices based on the pull-in effect have attracted

• increasing attention due to their unique ductility. This review summarizes nanoelectromechanical switches made by flexible materials and classifies and discusses their applications in, among others, radio frequency systems, microfluidic systems, and electrostatic discharge protection. It is supposed to give

• more and more difficult for traditional electronic devices made of rigid substrates to meet the needs of flexible and low-cost applications in complex environments. Flexible electronics have great potential for applications such as portable displays, electronic skin, and wearable healthcare. With the

Piezoelectric nanogenerator for bio-mechanical strain measurement

• Zafar Javed,
• Lybah Rafiq,
• Muhammad Anwaar Nazeer,
• Saqib Siddiqui,
• Muhammad Babar Ramzan,
• Muhammad Qamar Khan and
• Muhammad Salman Naeem

Beilstein J. Nanotechnol. 2022, 13, 192–200, doi:10.3762/bjnano.13.14

• last couple of years. Textile-based sensors, being flexible, are easy to fit in a garment and create no barrier to the wearer. Nowadays, wearable sensors based on conductive threads and conductive polymers are capable of measuring vital signs of the human body [4][5]. Tognetti et al. [6] designed and

• , which is capable of monitoring body angles. This sensor will be able to replace the battery being used in commonly available products and is more breathable, lightweight, and flexible. The developed sensor has been characterized through advanced techniques. The current density has been calculated and

Theoretical understanding of electronic and mechanical properties of 1T′ transition metal dichalcogenide crystals

• Seyedeh Alieh Kazemi,
• Sadegh Imani Yengejeh,
• Vei Wang,
• William Wen and
• Yun Wang

Beilstein J. Nanotechnol. 2022, 13, 160–171, doi:10.3762/bjnano.13.11

• hardness of 2H MoS2 are higher than those of 1T′ MoS2. The biggest difference can be found in the Young’s modulus. 2H MoS2 exhibits a Young’s modulus of 93 GPa, which is 12% higher than that of 1T′. All mechanical properties support that the 1T′ polytype is softer and more flexible than its 2H counterpart

A comprehensive review on electrospun nanohybrid membranes for wastewater treatment

• Senuri Kumarage,
• Imalka Munaweera and
• Nilwala Kottegoda

Beilstein J. Nanotechnol. 2022, 13, 137–159, doi:10.3762/bjnano.13.10

• flexible nanohybrid membrane of Pd NP-decorated polydopamine-SiO2/PVA, which can simultaneously remove organic dyes, chemicals, and oils [83]. (Figure 4 and Figure 5) Superhydrophilicity was found to be a synergistic effect of numerous hydroxy groups from SiO2 NPs and the nano/microscale surface roughness

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• catalytic area, SnO2 is an emerging material for removing contaminants such as organic dyes, phenolic compounds, and volatile organic compounds (VOCs) due to strongly oxidizing properties thanks to flexible energy band structure, rich defects, good chemical, and high thermal stability, and easily controlled

Enhancement of the piezoelectric coefficient in PVDF-TrFe/CoFe₂O₄ nanocomposites through DC magnetic poling

• Marco Fortunato,
• Alessio Tamburrano,
• Maria Paola Bracciale,
• Maria Laura Santarelli and
• Maria Sabrina Sarto

Beilstein J. Nanotechnol. 2021, 12, 1262–1270, doi:10.3762/bjnano.12.93

• Rome, 00184 Rome, Italy Department of Chemical Engineering Materials and Environment, Sapienza University of Rome, 00184 Rome, Italy 10.3762/bjnano.12.93 Abstract In the last years flexible, low-cost, wearable, and innovative piezoelectric nanomaterials have attracted considerable interest regarding

• constant and good piezoelectric properties suitable for the fabrication of flexible piezoelectric nanogenerators [1][2][3][4][5][6][7]. One of the most extensively investigated piezoelectric polymers is poly(vinylidene fluoride) (PVDF). This polymer has attracted a lot of interest due to its excellent

• in the fabrication of energy harvesting devices or wearable sensors for flexible electronics applications. Experimental The PVDF-TrFe/CoFe2O4 nanocomposite thin films were produced through spin coating. The CoFe2O4 nanoparticles (Sigma-Aldrich, 99%) were dispersed in N,N-dimethylformamide (DMF, Sigma

Electrical, electrochemical and structural studies of a chlorine-derived ionic liquid-based polymer gel electrolyte

• Ashish Gupta,
• Amrita Jain,
• Manju Kumari and
• Santosh K. Tripathi

Beilstein J. Nanotechnol. 2021, 12, 1252–1261, doi:10.3762/bjnano.12.92

• . Figure 1a shows the surface morphology of a pure PVdF-HFP film, indicating an uneven and rough surface of the crystalline polymer. Upon the addition of the ionic liquid [BDiMIM][Cl] on PVdF-HFP, the sizes of the grains start decreasing and the membrane becomes flexible and appears as a swollen structure

• -Brownian motion of the main chain due to the flexible nature of its constituent molecules. It is also observed from the figures that the decreasing pattern of the dielectric constant is more prominent toward lower frequencies as well as in the higher temperature domain. The decreasing pattern of the

Two dynamic modes to streamline challenging atomic force microscopy measurements

• Alexei G. Temiryazev,
• Andrey V. Krayev and
• Marina P. Temiryazeva

Beilstein J. Nanotechnol. 2021, 12, 1226–1236, doi:10.3762/bjnano.12.90

• flexible console with a sharp tip at the end. Two main classes of scanning methods can be distinguished, namely contact and dynamic scanning. During contact scanning, the tip is pressed against the surface and the pressing force is controlled by the deflection of the console. A similar way to control the

Assessment of the optical and electrical properties of light-emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles: a review

• Keshav Nagpal,
• Erwan Rauwel,
• Frédérique Ducroquet and
• Protima Rauwel

Beilstein J. Nanotechnol. 2021, 12, 1078–1092, doi:10.3762/bjnano.12.80

• quantum efficiencies, and luminance. De facto, plasmonic nanoparticles, such as Au and Ag have boosted the luminance of red, green, and blue emissions. When combined with carbon nanostructures they additionally offer new possibilities towards lightweight and flexible devices with better thermal management

• . The optoelectronic properties of SWNT thin films make them ideal for transparent conducting flexible electrodes in LED. In Figure 2, Aguirre et al. pre-fabricated vertical sheets of SWNT and then transferred them onto a glass substrate [21]. The maximum brightness and efficiency achieved in these SWNT

• graphene oxide is required based on the device configuration. Shi et al. obtained similar results with an excellent luminance of 53000 cd/m2, demonstrating its explicit applicability in flexible OLED [64]. Combinations of graphene oxide with polymers and metal oxides have also been evaluated. Lin et al

Use of nanosystems to improve the anticancer effects of curcumin

• Andrea M. Araya-Sibaja,
• Norma J. Salazar-López,
• Krissia Wilhelm Romero,
• José R. Vega-Baudrit,
• J. Abraham Domínguez-Avila,
• Carlos A. Velázquez Contreras,
• Ramón E. Robles-Zepeda,
• Mirtha Navarro-Hoyos and
• Gustavo A. González-Aguilar

Beilstein J. Nanotechnol. 2021, 12, 1047–1062, doi:10.3762/bjnano.12.78

• nanosystems. According to previous evidence, the use of nanosystems is highly flexible since it can be tailored for numerous applications with highly specific goals. Polymeric micelles and theranostics (a strategy that combines treatment and diagnostics) are two examples of such applications that are based on

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

• microfluidic elements for point-of-care diagnostics or drug delivery. Recent commercialization of TPP microtechnology by companies such as Nanoscribe GmbH (Germany) has enabled precise and flexible fabrication with submicron resolution [5]. Other manufacturing processes for microneedle fabrication include

Progress and innovation of nanostructured sulfur cathodes and metal-free anodes for room-temperature Na–S batteries

• Marina Tabuyo-Martínez,
• Bernd Wicklein and
• Pilar Aranda

Beilstein J. Nanotechnol. 2021, 12, 995–1020, doi:10.3762/bjnano.12.75

• result of the nanoporosity of the carbon matrix and the high nitrogen-doping content (ca. 18 atom %). Among all sulfur–carbon composite cathodes, flexible carbon-based skeletons are one of the most promising cathode materials given their ability to accommodate the fast volume changes of sulfur during the

• discharge process. Ma et al. [34] reported a conductive and flexible graphene aerogel cathode that effectively tolerated the volume changes under stabilization of the structure and led to an outstanding performance, showing an initial discharge capacity of 572.8 mAh·g−1 at 5C and an extremely low average

• ]. For instance, Hwang et al. [39] reported a cathode material based on one-dimensional sulfurized PAN nanofibers, and Kim et al. [40] reported the design of a flexible cathode that consists of a sulfurized PAN nanofiber web. The sulfurized PAN web was prepared by pyrolysis of PAN nanofibers and

The role of deep eutectic solvents and carrageenan in synthesizing biocompatible anisotropic metal nanoparticles

• Nabojit Das,
• Akash Kumar and
• Raja Gopal Rayavarapu

Beilstein J. Nanotechnol. 2021, 12, 924–938, doi:10.3762/bjnano.12.69

• (one sulfate group per disaccharide), iota carrageenan (two sulfate groups per disaccharide) and lambda carrageenan (three sulfate groups per disaccharide). Carrageenan forms highly flexible curly helical structures, which are responsible for their gelation property at room temperature. The number of

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

• targeted drug delivery. Li et al. [19] designed a fish-like magnetic actuation micro/nanorobot with a passive gold segment as the head, two active nickel segments as the body, and one passive gold segment as the caudal fin, all connected by a flexible structure of porous silver. The swimming mode of the

• and two nickel arm segments connected by flexible porous silver hinges. The flexible porous silver segment makes the robot swing symmetrically. By magnetizing the nickel segment, the two arms of the robot can swing in different directions under the action of the oscillating magnetic field, realizing a

• 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

• tubular spermbots reported here were guided by external magnets and sperm cells, and used sperm cells to push microtubules. The flagellum of this flexible artificial MNRs was basically a magnetic microhelix that was actuated via an external rotating magnetic field. These magnetic microspirals could move

• analyte. The magnetic bead (MaB) architecture is composed of a 15 nm iron oxide (Fe3O4) superparamagnetic core encased in a silica shell. The DNA strands are conjugated to the polymeric brush using a flexible linker. The brush permits passage of the nanoparticles through cell membranes, and prevents

• sperm cells; magnetic helical enzyme carriers for the cumulus cell removal by enzymes (e.g., hyaluronidase); artificial flagella with multiple windings and a claw-shaped sperm carrier for the delivery of immotile sperm cells; artificial flexible flagella for transport of immotile spermatozoa; stimuli

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

• , and to suggest a rapid response and versatile adaptability of the AMS in a relatively short evolutionary time [163]. The Turing model indicates a fast response when animals face changes in surface composition, contributing to a flexible adaptability of the functionalized attachment surfaces. Similar

• , which makes the pad material even more flexible. The structural anisotropy of the pad material is also responsible for the frictional anisotropy [129]. The friction is higher while the pad is sliding in a proximal direction because the fibres of smooth pads or hairs of hairy pads can be more easily

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

• for the design of sterilization and algae removal [72], wastewater treatment [73][74], and electrochemical corrosion protection of metal surfaces and battery cathodes [56][75][76]. TENG-based special flexible pressure sensors can be placed on the surface of human skin to monitor the physiological

• recognition. The stretchable sensor is installed on a glove by using a flexible material. When the fingers move, each finger generates an electrical signal. These signals are classified by using ML algorithms to obtain the text, and finally the text is converted into speech output. The method of ML processing

• throat. Voice print recognition and speech recognition can be realized by employing back-end data processing technology [88]. PENG/TENG-based self-powered sensors are flexible and highly sensitive, which can reduce inconveniences of a sensor system during physical training [41]. Back-end intelligent

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

• flexibility after the ink coating. The maximum transmittance value of as-prepared PET films in the visible region was estimated to be about 92.5% with a sheet resistance value of ca. 20 Ω/sq. This makes the films a potential substitute to commonly used expensive indium tin oxide (ITO) in the field of flexible

• toxic composition. Moreover, the sputtering process is time-consuming and sputtering make the films brittle, which limits the application in flexible applications [5]. Numerous materials are under consideration to overcome these challenges. In the past few years, certain materials, such as graphene

• , carbon nanotubes (CNT), conductive polymers, and metallic nanowires, have been tested commercially as alternative to ITO films for flexible optoelectronic devices [6][7][8][9]. Amongst them, graphene and carbon materials, particularly CNTs, display low optical transparency and high sheet resistance owing

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

• -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

• satisfies the needs of reliability for flexible tactile sensors in realizing human–machine interfaces. This work expands the potential application of S-TENGs from wearable electronics and smart sensing systems to real-time robotics control and virtual reality/augmented reality interactions. Keywords: human

• source for electronic devices. Another potential application for the S-TENG is as flexible tactile sensor that can serve as electronic skin for a more comfortable interactive experience between humans and external objects by sensing all kinds of information, such as size, shape, and texture [26][27]. The

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

• Qingchun Wang Wai Ting Siok Department of Linguistics, The University of Hong Kong, Hong Kong, China 10.3762/bjnano.12.27 Abstract In recent years, researchers have studied how nanotechnology could enhance neuroimaging techniques. The application of nanomaterial-based flexible electronics has the

• reading processing. We then outline the strengths and weaknesses of iEEG in studying human cognition and the development of intracranial recordings that use brain-compatible flexible electrodes. We close by discussing the potential advantages and challenges of future investigations adopting nanomaterial

• -based flexible electronics for intracranial recording in patients with aphasia. Keywords: aphasia; flexible electronics; intracranial electroencephalography (iEEG); language processing; neuroimaging techniques; Introduction Aphasia is an impairment in language and communication, which results from

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

• . This includes all raster styles that are available in the high-level approach but also user-defined styles, such as the back-stitching depicted in Figure 3b,c. The provided tools allow for flexible pattern generation and mitigate typical problems in ion beam-based machining. As the local material

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

• ][15] and biomedical applications [16]. FEBID provides a flexible direct-write technique to fabricate complex 3D structures, which are hard to realize using resist-based planar lithography processes. However, when using organometallic precursors, usually, undesired dissociation fragments also end up in

• influence on the FEBID process. Testing apparatus A more flexible setup than a traditional GIS was required for the exploration and testing of a large series of precursors. Commercially available GIS have a limited temperature range. For example, the maximum allowable temperature of the Thermo Fisher

The nanomorphology of cell surfaces of adhered osteoblasts

• Christian Voelkner,
• Mirco Wendt,
• Regina Lange,
• Max Ulbrich,
• Martina Gruening,
• Susanne Staehlke,
• Barbara Nebe,
• Ingo Barke and
• Sylvia Speller

Beilstein J. Nanotechnol. 2021, 12, 242–256, doi:10.3762/bjnano.12.20

• flexible. Figure 2a shows an example of a typical SICM topography of the border region in the live state (see Figure 2b for the corresponding bright-field microscopy image). Features with lateral dimensions of approximately 1 µm × 0.8 µm protruding 100–300 nm from the surrounding (Figure 2c), at a density

• current error appears counterintuitive regarding the material properties. However, considering the fin or springboard morphology of ruffles, the elasticity may not result from changes of material properties only but also from the flexible shape. Thus, the extremely low error probably points towards lower

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

• with perfect pattern detection accuracies of 100% and 98%, respectively. Keywords: electrooculography (EOG); flexible electronics; graphene; human–computer interaction (HCI); human–machine interface (HMI); personal assistive device (PAD); wearable smart textile; Introduction Eye tracking technologies

• stable graphene coating on the textiles. The prepared graphene textiles were then cut into pieces (ca. 3 × 3 cm) and mounted on flexible, polyethylene-based foam paddings, which were sandwiched between metallic snap fasteners in order to establish an electrical connection with the front-end circuitry. In

• ” electrodes, the functionality of which degrades over time [23]. However, one common issue in dry electrodes is the relatively high skin-electrode contact impedance, which causes susceptibility to physical movements and power line interferences resulting in signal distortions. While the flexible, foldable

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

• [39][40][41][42][43][44], high-voltage sources [45], self-powered systems [46][47][48][49][50], and blue energy harvesting devices [51][52][53][54][55][56]. Paper, by far one of the most inexpensive and flexible materials widely used in daily life, was developed more than 2000 years ago in China

• , and has tremendous advantages over the majority of other materials (e.g., it is lightweight, renewable, and air-permeable). Besides, paper is flexible and can be easily folded or bent into 3D structures without causing structural damage. In the last decades, paper-based electronic devices, such as

• process or to rotary screen printing, which enables a facile and high-throughput printing on curved surfaces. The deposition process assisted with soft stencils is another “bottom-up” method for the preparation of functional materials on flexible and irregular surfaces. Even though P-TENGs require