Search

The capability of plasmonic nanostructures in generating superchiral near‐fields holds great potential for a wide range of applications, including enantioselective sensing, medical diagnosis, and chirality‐based bioimaging. To implement high‐performance chiral nanophotonic devices, achieving in situ tuning of chiroptical activity in plasmonic nanostructures is highly desirable yet remains a formidable challenge. Here, a straightforward method is developed for deterministic assembly of plasmonic nanosphere trimers using spectroscopy‐assisted nano‐manipulation. The technique offers in situ, real‐time, and site‐specific control over the chiroptical response of trimers by adjusting their vertex angle and in‐plane orientation. The combination of numerical simulations with the Born‐Kuhn model reveals that oblique excitation effectively induces the symmetry breaking of the trimer structure, resulting in a preferential response of two distinct hybridized plasmonic modes to the handedness of light. Consequently, this yields a significant chiroptical response with the g factor up to 0.37. Remarkably, the trimer with an optimized obtuse angle exhibits a 193‐fold enhancement of optical chirality density, enabling the detection of molecular chirality with a record‐large spectral dissymmetric factor of 12 nm. The study facilitates the rational design of plasmonic nanostructures, offering promising prospects for chiral sensing at the single‐molecule level and asymmetric photocatalysis. [ABSTRACT FROM AUTHOR]

Micro and nano-scale manipulation of living matter is crucial in biomedical applications for diagnostics and pharmaceuticals, facilitating disease study, drug assessment, and biomarker identification. Despite advancements, trapping biological nanoparticles remains challenging. Nanotweezer-based strategies, including dielectric and plasmonic configurations, show promise due to their efficiency and stability, minimizing damage without direct contact. Our study uniquely proposes an inverted hybrid dielectric–plasmonic nanobowtie designed to overcome the primary limitations of existing dielectric–plasmonic systems, such as high costs and manufacturing complexity. This novel configuration offers significant advantages for the stable and long-term trapping of biological objects, including strong energy confinement with reduced thermal effects. The metal's efficient light reflection capability results in a significant increase in energy field confinement (EC) within the trapping site, achieving an enhancement of over 90% compared to the value obtained with the dielectric nanobowtie. Numerical simulations confirm the successful trapping of 100 nm viruses, demonstrating a trapping stability greater than 10 and a stiffness of 2.203 fN/nm. This configuration ensures optical forces of approximately 2.96 fN with an input power density of 10 mW/μm2 while preserving the temperature, chemical–biological properties, and shape of the biological sample. [ABSTRACT FROM AUTHOR]

Von Willebrand factor (VWF) is a multimer with a variable number of protomers, each of which is a head-to-head dimer of two multi-domain monomers. VWF responds to shear through the unfolding and extension of distinct domains, thereby mediating platelet adhesion and aggregation to the injured blood vessel wall. VWF's C1-6 segment uncoils and then the A2 domain unfolds and extends in a hierarchical and sequential manner. However, it is unclear whether there is any reservoir of further extensibility. Here, we explored the presence of cryptic extensibility in VWF by nanodissecting individual, pre-stretched multimers with atomic force microscopy (AFM). The AFM cantilever tip was pressed into the surface and moved in a direction perpendicular to the VWF axis. It was possible to pull out protein loops from VWF, which resulted in a mean contour length gain of 217 nm. In some cases, the loop became cleaved, and a gap was present along the contour. Frequently, small nodules appeared in the loops, indicating that parts of the nanodissected VWF segment remained folded. After analyzing the nodal structure, we conclude that the cryptic extensibility lies within the C1-6 and A1-3 regions. Cryptic extensibility may play a role in maintaining VWF's functionality in extreme shear conditions. [ABSTRACT FROM AUTHOR]

This study showcases an experimental demonstration of near‐field optical trapping and dynamic manipulation of an individual extracellular vesicle. This is accomplished through the utilization of a plasmonic dielectric nanoantenna designed to support an optical anapole state—a non‐radiating optical state resulting from the destructive interference between electric and toroidal dipoles in the far‐field, leading to robust near‐field enhancement. To further enhance the field intensity associated with the optical anapole state, a plasmonic mirror is incorporated, thereby boosting trapping capabilities. In addition to demonstrating near‐field optical trapping, the study achieves dynamic manipulation of extracellular vesicles by harnessing the thermoelectric effect. This effect is induced in the presence of an ionic surfactant, cetyltrimethylammonium chloride, combined with plasmonic heating. Furthermore, the thermoelectric effect improves trapping stability by a deep trapping potential. In summary, the hybrid plasmonic‐dielectric trapping platform offers a versatile approach for actively transporting, stably trapping, and dynamically manipulating individual extracellular vesicles. [ABSTRACT FROM AUTHOR]

In recent years, the scientific community’s interest in nanoscience and nanotechnology stems from the increasing capability to manipulate matter at the nanoscale. Nanotechnology development is closely linked to fabricating and characterizing structures below 100 nm, driven by technological advancements enabling their in-depth analysis. Up to now, several top-down and bottom-up nanofabrication approaches have been developed to realize a plethora of nanostructures. Although effective, these methods have many drawbacks like high costs and limitations in feature size. In this scenario, Scanning Probe-based Lithography (SPL) emerges as a very promising alternative to conventional nanofabrication techniques, overcoming their main method limitations with versatility, flexibility, low cost, and nanoscale resolution. This review focuses on mechanical Scanning Probe-based Lithography (m-SPL), tracing its evolution from inception to recent advances. Different m-SPL methods, such as Nanoindentation, Static and Dynamic Plowing lithography, Nanomilling, and their variants are discussed in-depth, emphasizing their advantages and drawbacks, and highlighting their application. Moreover, this review explores the effects of combining m-SPL with other energy sources, such as heat and electric energy, and outlines future perspectives in the field. Overall, m-SPL stands out as a promising avenue in nanofabrication, offering sub-nanometer resolution and diverse material manipulation capabilities.

Atomic force microscopy (AFM) is an analytical technique that is increasingly utilized to determine interaction forces on the colloidal and cellular level. Fluidic force microscopy, also called FluidFM, became a vital tool for biomedical applications. FluidFM combines AFM and nanofluidics by means of a microchanneled cantilever that bears an aperture instead of a tip at its end. Thereby, single colloids or cells can be aspirated and immobilized to the cantilever, for example, to determine adhesion forces. To allow for quantitative measurements, the so‐called (inverse) optical lever sensitivity (OLS and InvOLS, respectively) must be determined, which is typically done in a separate set of measurements on a hard, non‐deformable substrate. Here, we present a different approach that is entirely based on hydrodynamic principles and does make use of the internal microfluidic channel of a FluidFM‐cantilever and an external pressure control. Thereby, a contact‐free calibration of the (inverse) optical lever sensitivity (InvOLS) becomes possible in under a minute. A quantitative model based on the thrust equation, which is well‐known in avionics, and finite element simulations, is provided to describe the deflection of the cantilever as a function of the externally applied pressure. A comparison between the classical and the here‐presented hydrodynamic method demonstrates equal accuracy. [ABSTRACT FROM AUTHOR]

Nanotechnology has been considered with the aim of recognizing the structural and mechanical properties as well as improving the treatment and diagnostic process in the field of medicine. The process of nanomanipulation by examining healthy and cancerous tissues in nanoscale is one of the processes used in this field. Therefore, in this article, considering the importance of recognizing the properties of cancerous and healthy tissues in improving the treatment and diagnosis process, one of the most common types of cancer has been studied. Young modulus has been used as a parameter in the diagnosis of cancerous tissue and its value has been calculated for gastric cancerous tissue. To achieve this goal, atomic force microscopy (AFM) was used during the manipulation process. This tool with the ability to study cancerous tissues in different environments and with the least amount of damage to the target tissue, is one of the effective tools in the field of nanomanipulation. The parameter studied in this study is the geometry of gastric cancer tissue. Therefore, the simulations have been performed by considering contact models with spherical, cylindrical and crowned rollers geometries. The force-indentation depth diagram for gastric tissue is plotted experimentally and compared with theoretical results. According to the experimental work done after reviewing the recorded topographic images, the approximate range of the Young's modulus value for gastric tissue has been calculated according to different geometries. Since the geometry of the crowned rollers is closer to the geometry of the gastric tissue, it has a higher accuracy and the values of the Young's modulus have been calculated according to this geometry in the range of 316–310 KPa.

Micro and nano-scale manipulation of living matter is crucial in biomedical applications for diagnostics and pharmaceuticals, facilitating disease study, drug assessment, and biomarker identification. Despite advancements, trapping biological nanoparticles remains challenging. Nanotweezer-based strategies, including dielectric and plasmonic configurations, show promise due to their efficiency and stability, minimizing damage without direct contact. Our study uniquely proposes an inverted hybrid dielectric–plasmonic nanobowtie designed to overcome the primary limitations of existing dielectric–plasmonic systems, such as high costs and manufacturing complexity. This novel configuration offers significant advantages for the stable and long-term trapping of biological objects, including strong energy confinement with reduced thermal effects. The metal’s efficient light reflection capability results in a significant increase in energy field confinement (EC) within the trapping site, achieving an enhancement of over 90% compared to the value obtained with the dielectric nanobowtie. Numerical simulations confirm the successful trapping of 100 nm viruses, demonstrating a trapping stability greater than 10 and a stiffness of 2.203 fN/nm. This configuration ensures optical forces of approximately 2.96 fN with an input power density of 10 mW/μm2 while preserving the temperature, chemical–biological properties, and shape of the biological sample.

Abstract Atomic force microscopy (AFM) is an analytical technique that is increasingly utilized to determine interaction forces on the colloidal and cellular level. Fluidic force microscopy, also called FluidFM, became a vital tool for biomedical applications. FluidFM combines AFM and nanofluidics by means of a microchanneled cantilever that bears an aperture instead of a tip at its end. Thereby, single colloids or cells can be aspirated and immobilized to the cantilever, for example, to determine adhesion forces. To allow for quantitative measurements, the so‐called (inverse) optical lever sensitivity (OLS and InvOLS, respectively) must be determined, which is typically done in a separate set of measurements on a hard, non‐deformable substrate. Here, we present a different approach that is entirely based on hydrodynamic principles and does make use of the internal microfluidic channel of a FluidFM‐cantilever and an external pressure control. Thereby, a contact‐free calibration of the (inverse) optical lever sensitivity (InvOLS) becomes possible in under a minute. A quantitative model based on the thrust equation, which is well‐known in avionics, and finite element simulations, is provided to describe the deflection of the cantilever as a function of the externally applied pressure. A comparison between the classical and the here‐presented hydrodynamic method demonstrates equal accuracy.

Carbon nanotubes (CNTs) are cylindrical nanostructures fabricated from carbon atoms that seem like seamless cylinders composed of rolled sheets of graphite. Owing to the unique properties of single-walled carbon nanotubes (SWCNTs), they are a promising candidate in various fields such as chemical sensing, hydrogen storage, catalyst support, electronics, nanobalances, and nanotubes. Because of their small size, large surface area, high sensitivity, and reversible behavior at room temperature, CNTs are ideal for measuring gas. They also show improved electron transfer when used as electrodes in electrochemical reactions and serve as solid media for protein immobilization on biosensors. SWCNTs can be metallic or semi-conductive, counting on their structural properties. In this study, an atomic force microscope (AFM) was used as a powerful tool to manipulate and disaggregate SWCNTs. By precisely controlling the AFM probe, it was possible to manipulate individual SWCNTs and separate them from the bundle structures. Next, the electrical transport of disaggregated SWCNTs was studied using the conductive atomic force microscope (cAFM) technique. Thus, current-voltage measurements on the unbundled branches of SWCNTs were carried out. Interestingly, these current-voltage measurements have allowed us to unravel the complex electrical characteristics of the nanotube bundle, which is a very crucial issue for gating effects as well as the resistance of the interconnects within carbon nanotube network devices. [ABSTRACT FROM AUTHOR]

Nanowires have emerged as promising one-dimensional materials with which to construct various nanocircuits and nanosensors. However, measuring the electrical properties of individual nanowires directly remains challenging because of their small size, thereby hindering the comprehensive understanding of nanowire-based device performance. A crucial factor in achieving reliable electrical characterization is establishing well-determined contact conditions between the nanowire sample and the electrodes, which becomes particularly difficult for soft nanowires. Introduced here is a novel technique for measuring the conductivity of an individual nanowire with the aid of automated nanomanipulation using an atomic force microscope. In this method, two nanowire segments cut from the same silver nanowire are positioned onto a pair of gold electrodes, serving as flexible nanoprobes to establish controllable contact with the sample. By changing the contact points along the nanowire sample, conductivity measurements can be performed on different regions, thereby eliminating the influence of contact resistance by analyzing multiple current–voltage curves. Using this approach, the resistivity of a 100-nm-diameter silver nanowire is determined to be 3.49 × 10−8 Ω m. ARTICLE HIGHLIGHTS: HIGHLIGHTS • Two flexible nanoprobes in the form of silver nanowires were fabricated using a series of complex AFM manipulation strategies including manipulating individual nanowires via translation, rotation, and cutting. • In situ measurements of the electrical conductivity of an individual nanowire were conducted at multiple points using the flexible nanoprobes, thereby effectively mitigating the influence of contact resistance and enabling determination of the nanowire's resistivity. [ABSTRACT FROM AUTHOR]

In the macro scale, surface forces such as friction and adhesion are of little importance and can be ignored. But in the micro/nano world, these forces are of great importance. For this purpose, in order to simulate the manipulation of nanoparticles based on the atomic force microscope, various friction models can be used, including the HK friction model. Accurate calculation of force and critical time, respectively, in order not to damage the particle and to reach the target point in the manipulation process is important and necessary. In this research, data were collected using the Taguchi test design method in three levels. The amount of force and critical time were calculated for each test. Then, with the help of analysis using the signal-to-noise ratio method, to investigate the effect of the input parameters of the HK friction model including, 1 f, 2 f,B and M The reduction of the critical force and the increase of the critical time in mamipulation the gold nanoparticle with a radius of 50 nm on the silicon oxide substrate have been discussed. Based on the obtained results, parameter B as the first parameter and M as the second parameter with the lowest signal-to-noise ratio on reducing the critical force and with the highest signal-to-noise ratio at the critical time at level 3 with values of -1.869 and -0.3419 [ABSTRACT FROM AUTHOR]

Atomic force microscopy is a powerful and precise tool for identifying particle properties and studying intermolecular forces, surface topography, and particle manipulation in the micro-nano dimension. Nanomanipulation is one process that makes good use of this tool. Today, with advances in science and technology, manipulation is used to modify and manufacture the properties of materials, produce more valuable medical components and fewer raw materials, alter the structure of living cells and much more. We are working at the nanoscale. Therefore, in this study, we used atomic force microscopy to investigate the mechanical properties of breast cancer tissue during the nanomanipulation process. By considering the changes induced by the displacement force, force curves and penetration depths are plotted over time. Given the importance of nanoparticle-particle contact and the tatara contact model and breast cancer tissue geometry, simulations were performed to extract the Young's modulus. Experimental experiments and experimental charts were also performed to verify the agreement between the results of the simulation process based on atomic force microscopy. Finally, using the comparisons made in this study and considering the tatara contact model, a range of 2–2.5 kPa was calculated for breast cancer tissue volume. [ABSTRACT FROM AUTHOR]

The adhesive behavior of one-dimensional (1D) materials, such as nanotubes and nanowires, plays a decisive role in the effective fabrication, functionality, and reliability of novel devices that integrate 1D components, as well as in biomimetic adhesives based on 1D arrays. This review compiles and critically evaluates recent experimental techniques that aim to characterize the adhesion behavior of interfaces formed by 1D materials, including when such materials are brought into contact with a substrate or adjacent 1D materials. The conformation of 1D material to surfaces and the associated occurrence of multi-asperity contact are discussed, and the coupling of adhesion and friction during interfacial attachment and detachment is explored. The use of 1D materials as reinforcement agents in nanocomposites and the associated interfacial characterization techniques are considered. The potential for the environmental conditions that exist during sample preparation and adhesion testing to influence 1D interfacial interactions and, ultimately, to alter the adhesion behavior of a 1D material is scrutinized. Finally, a brief perspective is provided on ongoing challenges and future directions, which include the methodical investigation of the testing environment and the alteration of adhesion through surface modification.

The measurement method, which utilizes nanomanipulation of the nanowires onto a specially prepared substrate, was presented. It introduced a four-point resistance measurement setup on a chip suited for scanning probe microscopy measurements, integrating connectors and a nanowire specimen. A study on the resistance and resistivity of the thermally post-treated ZnO nanowires at 200 °C and 300 °C in air showed the dependence of these electrical parameters on the annealing temperature. The investigations of the electrical properties of blocks built on the basis of nanowires and their related devices could provide a useful guide not only for designing, fabricating and optimizing electromechanical nanodevices based on nanowires but also for their safe operation in future electronic applications. [ABSTRACT FROM AUTHOR]

Goals such as not harming healthy tissues and other organs when using medicine and identifying cancerous tissues as soon as possible have led to the entry of nanoscience into the field of medicine. In this regard, a research was conducted considering various tools and methods, and the most desirable of these methods was the nanomanipulation method based on the atomic force microscope due to its many applications in the study of cell tissues in different environments. Therefore, in this article, in order to find the optimal amount of force and critical time in nanomanipulation of cancer tissue, with the aim of exploring the surface and obtaining information about gastric cancer tissue with the least damage, 2D simulation of nanomanipulation has been carried out. The important factor investigated in this research is friction, which is one of the factors that resist movement and has a direct effect on force and critical time. Therefore, with the development of simple friction models, considering Carlson-Batista, Lemaitre-Carlson and FKT friction models, force-time diagrams have been drawn and critical force and time values have been calculated. The lowest value of the force was equal to 0.453 nN and the lowest value of the critical time was equal to 45 ms, which was obtained from the simulation with the FKT friction model. Also, by comparing these values with past researches, a decrease in force and critical time compared to the LuGre friction model has been seen. [ABSTRACT FROM AUTHOR]

Since their inception, optical tweezers have proven to be a useful tool for improving human understanding of the microscopic world with wide-ranging applications across science. In recent years, they have found many particularly appealing applications in the field of biomedical engineering which harnesses the knowledge and skills in engineering to tackle problems in biology and medicine. Notably, metallic nanostructures like gold nanoparticles have proven to be an excellent tool for OT-based micromanipulation due to their large polarizability and relatively low cytotoxicity. In this article, we review the progress made in the application of optically trapped gold nanomaterials to problems in bioengineering. After an introduction to the basic methods of optical trapping, we give an overview of potential applications to bioengineering specifically: nano/biomaterials, microfluidics, drug delivery, biosensing, biophotonics and imaging, and mechanobiology/single-molecule biophysics. We highlight the recent research progress, discuss challenges, and provide possible future directions in this field.

Molybdenum trioxide shows many attractive properties, such as a wide electronic band gap and a high relative permittivity. Monolayers of this material are particularly important, as they offer new avenues in optoelectronic devices, e.g., to alter the properties of graphene electrodes. Nanoscale electrical characterization is essential for potential applications of monolayer molybdenum trioxide. We present a conductive atomic force microscopy study of an epitaxially grown 2D molybdenum oxide layer on a graphene-like substrate, such as highly oriented pyrolytic graphite (HOPG). Monolayers were also investigated using X-ray photoelectron spectroscopy, atomic force microscopy (semi-contact and contact mode), Kelvin probe force microscopy, and lateral force microscopy. We demonstrate mobility of the unpinned island under slight mechanical stress as well as shaping and detachment of the material with applied electrical stimulation. Non-stoichiometric MoO3-x monolayers show heterogeneous behavior in terms of electrical conductivity, which can be related to the crystalline domains and defects in the structure. Different regions show various I–V characteristics, which are correlated with their susceptibility to electrodegradation. In this work, we cover the existing gap regarding nanomanipulation and electrical nanocharacterization of the MoO3 monolayer. [ABSTRACT FROM AUTHOR]

Over the past few decades, in situ transmission electron microscopy (TEM) has emerged as a powerful experimental technique for materials design and characterization. It offers unparalleled dynamic details of materials deformation under mechanical stimuli, providing fundamental insights into their deformation and failure mechanisms for various materials. In this review, we summarize recent advances on in situ TEM mechanical characterization techniques, including classical tension holders, nanoindentation holders, MEMS devices, thermal bimetallic-based techniques, and nanomanipulation techniques. The advantages and limitations of in situ TEM tests are also discussed. To provide a broader perspective, the article highlights promising opportunities for in situ TEM mechanical testing studies in characterization-processing-manufacturing based on nanomanipulation, ultrafast TEM, electron beam irradiation environmental conditions, data-driven machine learning, and integrated experimental and simulation characterization. This article aims to provide a comprehensive understanding of in situ TEM-based mechanical characterization techniques to promote the development of novel materials with improved mechanical properties for various applications.

The study of mechanical properties of tissues can be considered as biomarkers for early detection of cancer and help in new treatments. In this study, the Young's modulus of MCF-7 breast cancer tissue was extracted using atomic force microscopy (AFM) by measuring the interaction force of the sample and performing a simulation. The force–indentation depth diagram was plotted by averaging the experimental results. In this paper, the modulus of elasticity of breast cancer tissue has been extracted with complex models such as DMT, MD, BCP, and SUN. By comparing the experimental and theoretical results and by changing the amount of hypothetical Young's modulus in the spherical contact models, the Young's modulus of the cancer tissue is considered to be between 300 and 400 Pa. The geometry of the cell was also assumed to be spherical according to the images obtained by atomic force microscopy. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) are cylindrical nanostructures fabricated from carbon atoms that seem like seamless cylinders composed of rolled sheets of graphite. Owing to the unique properties of single-walled carbon nanotubes (SWCNTs), they are a promising candidate in various fields such as chemical sensing, hydrogen storage, catalyst support, electronics, nanobalances, and nanotubes. Because of their small size, large surface area, high sensitivity, and reversible behavior at room temperature, CNTs are ideal for measuring gas. They also show improved electron transfer when used as electrodes in electrochemical reactions and serve as solid media for protein immobilization on biosensors. SWCNTs can be metallic or semi-conductive, counting on their structural properties. In this study, an atomic force microscope (AFM) was used as a powerful tool to manipulate and disaggregate SWCNTs. By precisely controlling the AFM probe, it was possible to manipulate individual SWCNTs and separate them from the bundle structures. Next, the electrical transport of disaggregated SWCNTs was studied using the conductive atomic force microscope (cAFM) technique. Thus, current-voltage measurements on the unbundled branches of SWCNTs were carried out. Interestingly, these current-voltage measurements have allowed us to unravel the complex electrical characteristics of the nanotube bundle, which is a very crucial issue for gating effects as well as the resistance of the interconnects within carbon nanotube network devices.

Efficient and accurate path planning in a complex biological environment have become a challenge for nanorobot research. This paper first reviews the current path planning algorithms that can be used in the operation of nanorobots in the scientific community. The algorithms are mainly divided into four parts, including Dijkstra algorithm, A* algorithm, Rapidly-exploring Random Tree (RRT) algorithm, and Swarm Intelligence (SI) algorithm. In the application of SI, Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) are the most commonly used approaches to solve the path planning of nanorobot swarm. Then, their research status, advantages, and limitations are outlined in each section. The improvement of different algorithms in different environments is discussed while fully demonstrating that they are superior to other methods. Finally, the future research on optimal path planning is expected as the next step in high-precision control of nanorobot. This review aims to provide some ideas for the improvement of nanorobot performance and accelerate another leap of path planning technology in the field of nanomanipulation. [ABSTRACT FROM AUTHOR]

Nanomanipulation of molecular materials such as carbon nanotubes (CNTs) or new covalent organic frameworks (COFs) is key not only for the study of their fundamental physicochemical properties, but also for building and probing nanodevices. Therefore, we have investigated the tribological properties of oxidized MWCNTs (ox-MWCNTs) and their hybridization with COF building blocks (ox-MWCNTs@COF) adsorbed on a mica surface. We used the AFM tip to apply torsional forces on individual nanotubes. Depending on the manipulation parameters, the lateral displacements of the AFM tip slide and/or bend nanotubes enabling the direct quantification of the nanotube-mica adhesion. We found striking changes in the behaviour of the lateral force needed to manipulate each carbon nanotube variant which indicates an increased adhesion of ox-MWCNTs@COF with respect to ox-MWCNTs (∼10x). In addition, the use of the AFM tip as a mobile electrode enabled the measurement of electrical transport through individual nanotubes that revealed a rectifying behaviour of the ox-MWCNTs@COF with high resistivity, which was in contrast with the near ohmic performance of ox-MWCNTs. [Display omitted] [ABSTRACT FROM AUTHOR]

The tethered molecule exhibits characteristics of both free and fixed states, with the electrodynamics involved in its diffusion, electrophoresis, and stretching processes still not fully understood. We developed a Single-Molecule Manipulation, Identification, and Length Examination (SMILE) system by integrating piezoelectric devices with nanopipettes. This system enabled successful capture and stretching of tethered double-stranded DNA within the nanopore. Our research unveiled distinct capture ( r capture ) and stretch radii ( r stretch ) surrounding the DNA's anchor point. Notably, consistent ratios of capture radius for DNA of varying lengths (2k, 4k, and 6k base pairs) were observed across different capturing voltages, approximately 1:1.4:1.83, showing a resemblance to their gyration radius ratios. However, the ratios of stretch radius are consistent to their contour length ( L 0 ), with the stretching ratio ( r stretch / L 0 ) increasing from 70 to 90% as the voltage rose from 100 to 1000 mV. Additionally, through numerical simulations, we identified the origin of capture and stretch radii, determined by the entropic elasticity-induced capture barrier and the electric field-dominant escape barrier. This research introduces an innovative methodology and outlines research perspectives for a comprehensive exploration of the conformational, electrical, and diffusion characteristics of tethered molecules.

The measurement method, which utilizes nanomanipulation of the nanowires onto a specially prepared substrate, was presented. It introduced a four-point resistance measurement setup on a chip suited for scanning probe microscopy measurements, integrating connectors and a nanowire specimen. A study on the resistance and resistivity of the thermally post-treated ZnO nanowires at 200 °C and 300 °C in air showed the dependence of these electrical parameters on the annealing temperature. The investigations of the electrical properties of blocks built on the basis of nanowires and their related devices could provide a useful guide not only for designing, fabricating and optimizing electromechanical nanodevices based on nanowires but also for their safe operation in future electronic applications.

A new technique based on optical microscope nanomanipulation is developed to permit optical observation of the shearing process between cantilevered nanowires (NWs). Real‐time observation of the deflection shape of NWs during shearing under controlled environmental conditions enables their shear stress evolution to be evaluated with respect to relative humidity (RH). The average static and kinetic shear strengths, τ¯s=7.1±0.8 and τ¯k=5.2±1.1 MPa, are found to be insensitive to the RH within the range of 40–60%. When the RH increased to 74%, the shear strength values increase to τ¯s=18.7±3.0 and τ¯k=14.7±1.8 MPa. When the RH decreases to 20%, a dramatic increase in the static and kinetic shear strengths is observed: τ¯s=64.4±7.2 and τ¯k=49.6±5.8 MPa. Water films absorbed on the surface of NWs within the RH range of 40–60% can lubricate their frictional interface and thus dramatically decrease the shear strength. At high RH of above 60%, the viscous effects of a water meniscus condensed around the contact point between two NWs can significantly enhance the shear strength and dampen stick‐slip behavior. The detachment of two NWs is then controlled by the rupture of a meniscus bridge, leading to high ultimate shear strength value of several tens of MPa. [ABSTRACT FROM AUTHOR]

Noninvasive manipulation of nanoscopic species in liquids has attracted considerable attention due to its potential applications in diverse fields. Many sophisticated methodologies have been developed to control and study nanoscopic entities, but the low-power, cost-effective, and versatile manipulation of nanometer-sized objects in liquids remains challenging. Here, we present a dielectrophoretic (DEP) manipulation technique based on nanogap electrodes, with which the on-demand capturing, enriching, and sorting of nano-objects in microfluidic systems can be achieved. The dielectrophoretic control unit consists of a pair of swelling-induced nanogap electrodes crossing a microchannel, generating a steep electric field gradient and thus strong DEP force for the effective manipulation of nano-objects microfluidics. The trapping, enriching, and sorting of nanoparticles and DNAs were performed with this device to demonstrate its potential applications in micro/nanofluidics, which opens an alternative avenue for the non-invasive manipulation and characterization of nanoparticles such as DNA, proteins, and viruses. [ABSTRACT FROM AUTHOR]

Molybdenum trioxide shows many attractive properties, such as a wide electronic band gap and a high relative permittivity. Monolayers of this material are particularly important, as they offer new avenues in optoelectronic devices, e.g., to alter the properties of graphene electrodes. Nanoscale electrical characterization is essential for potential applications of monolayer molybdenum trioxide. We present a conductive atomic force microscopy study of an epitaxially grown 2D molybdenum oxide layer on a graphene-like substrate, such as highly oriented pyrolytic graphite (HOPG). Monolayers were also investigated using X-ray photoelectron spectroscopy, atomic force microscopy (semi-contact and contact mode), Kelvin probe force microscopy, and lateral force microscopy. We demonstrate mobility of the unpinned island under slight mechanical stress as well as shaping and detachment of the material with applied electrical stimulation. Non-stoichiometric MoO3-x monolayers show heterogeneous behavior in terms of electrical conductivity, which can be related to the crystalline domains and defects in the structure. Different regions show various I–V characteristics, which are correlated with their susceptibility to electrodegradation. In this work, we cover the existing gap regarding nanomanipulation and electrical nanocharacterization of the MoO3 monolayer.

• Novel method for measurement of single nanowires in terms of mechanical properties. • Nanowires with much larger diameters and stiffnesses can be measured. • Nanomanipulation of nanowires with secured placements on the substrate for singular tests. • Usage of AFM to perform topological and mechanical measurements with possible inclusion of electrical tests. [Display omitted] In this paper, we present the results of mechanical measurement of single nanowires (NWs) in a repeatable manner. Substrates with specifically designed mechanical features were used for NW placement and localization for measurements of properties such as Young's modulus or tensile strength of NW with an atomic force microscopy (AFM) system. Dense arrays of zinc oxide (ZnO) nanowires were obtained by one-step anodic oxidation of metallic Zn foil in a sodium bicarbonate electrolyte and thermal post-treatment. ZnO NWs with a hexagonal wurtzite structure were fixed to the substrates using focused electron beam-induced deposition (FEBID) and were annealed at different temperatures in situ. We show a 10-fold change in the properties of annealed materials as well as a difference in the properties of the NW materials from their bulk values with pre-annealed Young modulus at the level of 20 GPa and annealed reaching 200 GPa. We found the newly developed method to be much more versatile, allowing for in situ operations of NWs, including measurements with different methods of scanning probe microscopy. [ABSTRACT FROM AUTHOR]

[Display omitted] • m-SPL techniques allow the patterning at the nanoscale with unprecedented precision. • Nanoindentation is the easiest m-SPL, permitting the realization of nanoholes array. • AFM Plowing lithographies allow for patterning in contact and semicontact modes. • Static and Dynamic Plowing lithography stands for advanced m-SPL techniques. • Coupled m-SPL enhances the patterning capability and the properties of nanostructures. In recent years, the scientific community's interest in nanoscience and nanotechnology stems from the increasing capability to manipulate matter at the nanoscale. Nanotechnology development is closely linked to fabricating and characterizing structures below 100 nm, driven by technological advancements enabling their in-depth analysis. Up to now, several top-down and bottom-up nanofabrication approaches have been developed to realize a plethora of nanostructures. Although effective, these methods have many drawbacks like high costs and limitations in feature size. In this scenario, Scanning Probe-based Lithography (SPL) emerges as a very promising alternative to conventional nanofabrication techniques, overcoming their main method limitations with versatility, flexibility, low cost, and nanoscale resolution. This review focuses on mechanical Scanning Probe-based Lithography (m-SPL), tracing its evolution from inception to recent advances. Different m-SPL methods, such as Nanoindentation, Static and Dynamic Plowing lithography, Nanomilling, and their variants are discussed in-depth, emphasizing their advantages and drawbacks, and highlighting their application. Moreover, this review explores the effects of combining m-SPL with other energy sources, such as heat and electric energy, and outlines future perspectives in the field. Overall, m-SPL stands out as a promising avenue in nanofabrication, offering sub-nanometer resolution and diverse material manipulation capabilities. [ABSTRACT FROM AUTHOR]

Recently, Ti-Ni based intermetallic alloys with shape memory effect (SME) have attracted much attention as promising functional materials for the development of record small nanomechanical tools, such as nanotweezers, for 3D manipulation of the real nano-objects. The problem of the fundamental restrictions on the minimal size of the nanomechanical device with SME for manipulation is connected with size effects which are observed in small samples of Ti-Ni based intermetallic alloys with thermoplastic structural phase transition from austenitic high symmetrical phase to low symmetrical martensitic phase. In the present work, by combining density functional theory and molecular dynamics modelling, austenite has been shown to be more stable than martensite in nanometer-sized TiNi wafers. In this case, the temperature of the martensitic transition asymptotically decreases with a decrease in the plate thickness h, and the complete suppression of the phase transition occurs for a plate with a thickness of 2 nm, which is in qualitative agreement with the experimental data. Moreover, the theoretical values obtained indicate the potential for even greater minimization of nanomechanical devices based on SME in TiNi. [ABSTRACT FROM AUTHOR]

Electrical characterization of semiconducting oxide nanowires (NWs) is mostly performed using complex techniques, which necessitates a series of costly nanofabrication procedures. In this work, with the aim to provide a low-cost, feasible, facile, and reproducible approach for enabling the study of NW electrical properties, we report direct electrical measurements on individual and overlapped suspended zinc oxide NWs (ZnO NWs). We have succeeded in constructing both two- and three-terminal devices simply by employing tungsten (W) nanoprobes with the aid of a nanomanipulation system embedded inside a scanning electron microscope's vacuum chamber. Stable contacts were established using the Joule heating effect and e-beam exposure at the junctions between the NW and the pre-cleaned W tips. P-channel field-effect transistor devices were achieved with an on–off current ratio of ∼101, a threshold voltage (>1.5 V), a transconductance of ∼16 μS, a sub-threshold swing of ∼220 mV/decade, and field-effect carrier mobility roughly estimated to be around 926.4 cm2/(V·s) after correction for contact resistances/optimization. The average resistivity of ZnO NWs was calculated to be ∼2.23 × 10–2 Ω·cm for NWs with diameters between 70 and 500 nm. Besides, we have demonstrated a contact resistance of ∼19.60 kΩ and a Schottky barrier height of ∼0.37 eV present at W/ZnO NW interfaces. The contact resistance between two overlapped ZnO NWs was estimated to be ∼283 kΩ, which is relatively higher than that offered between W/ZnO NWs. This work provides a solid experimental procedure to address true intrinsic electrical properties at metal/semiconductor interfaces, and our findings have potential applications in next-generation 3D suspended ZnO NW-based nanoelectronic devices. [ABSTRACT FROM AUTHOR]

Since the manipulation of particles using atomic force microscopy is not observable in real-time, modeling the manipulation process is of notable importance, enabling us to investigate the dynamical behavior of nanoparticles. To model this process, previous studies employed classical continuum mechanics and molecular dynamics simulations which had certain limitations; the former does not consider size effects at the nanoscale while the latter is time consuming and faces computational restrictions. To optimize accuracy and computational costs, a new nonclassical modeling of the nanomanipulation process based on the modified couple stress theory is proposed that includes the size effects. To this end, after simulating the critical times and forces that are required for the onset of nanoparticle motion on the substrate, along with the dominant motion mode, the nonclassical theory of continuum mechanics and a developed von Mises yield criterion are employed to investigate the dynamical behavior of a cylindrical gold nanoparticle during manipulation. Timoshenko and Euler–Bernoulli beam theories based on the modified couple stress theory are used to model the dynamics of cylindrical gold nanoparticles while the finite element method is utilized to solve the governing equations of motion. The results show a difference of 90% between the classical and nonclassical models in predicting the maximum deflection before the beginning of the dominant mode and a difference of more than 25% in the dynamic modeling of a 200 nm manipulation of a gold nanoparticle with a length of 25 µm and aspect ratio of 30. This difference increases with each increment of the aspect ratio and reduction of manipulation distance. Furthermore, by applying an extended von Mises criterion on the modified couple stress theory, it is found that the failure aspect ratio of a cylindrical gold nanoparticle based on nonclassical models is 212% more than that of the classical model. In the end, the results are compared with those of the classical method on polystyrene nanorods. The results for cylindrical gold nanoparticles indicate that the material length scale has a major effect on the exact positioning of cylindrical nanoparticles.

Micrometer-scale circular graphene/β-Ga 2 O 3 structures are fabricated by transferring graphene layers to (2 ‾ 01) and (010) bulk gallium oxide substrates. Focused ion beam etching is used to downscale the area of the graphene/β-Ga 2 O 3 junctions, and a nanoprobe-based approach is employed for their electrical characterization in the chamber of the scanning electron microscope. Using this approach, the impact of defects in graphene on the electrical characteristics of the junctions is suppressed. A significant difference between the structures fabricated on (2 ‾ 01) and (010) gallium oxide surfaces is further demonstrated. By numerical fitting of the measured data, several electric charge transport mechanisms are distinguished depending on the applied bias and orientation of the gallium oxide surface. [ABSTRACT FROM AUTHOR]

• Anion intercalation in graphite produces pressurized blisters on the basal plane. • Mechanical characterization of these pressurized blisters can be used as model system. • Blisters show a stiffness in a range between 1 and 10 MPa. • Blisters can be moved or cut by an AFM tip. • The deformation of graphite basal plane by blisters seems to be elastic. Electrochemical anion intercalation of highly oriented pyrolytic graphite in mineral acids (such as sulfuric, perchloric, etc.) represents a model system to study (i) the intercalation process of chemical compounds in stratified crystals; (ii) the evolution of gases at the surface and inside the sample and (iii) the evolution of swollen regions of graphite, called blisters. Although the explanation of the blister evolution mechanism can be dated back to the nineties of the last century, many chemical and physical properties have been explored only very recently. In particular, the mechanical properties of blisters on graphite are not widely discussed in the literature. Here, we employ in-situ atomic force microscopy (AFM) to characterize the blister stiffness. The same AFM tip is used to move mechanically the blister on the basal plane or even cut it. As a consequence of this operation, the entrapped gases (namely, CO, CO 2 and O 2) can deflate and the swollen graphite layers lay down to recompose the graphite basal plane. [Display omitted] [ABSTRACT FROM AUTHOR]

Since their inception, optical tweezers have proven to be a useful tool for improving human understanding of the microscopic world with wide-ranging applications across science. In recent years, they have found many particularly appealing applications in the field of biomedical engineering which harnesses the knowledge and skills in engineering to tackle problems in biology and medicine. Notably, metallic nanostructures like gold nanoparticles have proven to be an excellent tool for OT-based micromanipulation due to their large polarizability and relatively low cytotoxicity. In this article, we review the progress made in the application of optically trapped gold nanomaterials to problems in bioengineering. After an introduction to the basic methods of optical trapping, we give an overview of potential applications to bioengineering specifically: nano/biomaterials, microfluidics, drug delivery, biosensing, biophotonics and imaging, and mechanobiology/single-molecule biophysics. We highlight the recent research progress, discuss challenges, and provide possible future directions in this field.

Noninvasive manipulation of nanoscopic species in liquids has attracted considerable attention due to its potential applications in diverse fields. Many sophisticated methodologies have been developed to control and study nanoscopic entities, but the low-power, cost-effective, and versatile manipulation of nanometer-sized objects in liquids remains challenging. Here, we present a dielectrophoretic (DEP) manipulation technique based on nanogap electrodes, with which the on-demand capturing, enriching, and sorting of nano-objects in microfluidic systems can be achieved. The dielectrophoretic control unit consists of a pair of swelling-induced nanogap electrodes crossing a microchannel, generating a steep electric field gradient and thus strong DEP force for the effective manipulation of nano-objects microfluidics. The trapping, enriching, and sorting of nanoparticles and DNAs were performed with this device to demonstrate its potential applications in micro/nanofluidics, which opens an alternative avenue for the non-invasive manipulation and characterization of nanoparticles such as DNA, proteins, and viruses.

• Modeling of the second phase of nanoparticles nanomanipulation (elliptic and cubic nanoparticle). • Considering the effect of initial nanoparticles impact before contact on the process of second phase of nanomanipulation. • Investigation of nanoparticles impact using different theories. • Simulation of the motion path of nanoparticles. This article investigates the effect of impact on the dynamic modeling and simulation of cubic and elliptic nanoparticles in the manipulation process based on atomic force microscopy (AFM). First, the dynamic equations prior to the motion are presented. Then, according to these equations, two assumptions are considered for nanoparticles motion. Using the Hertz, JRK, and Jamari theories as well as the approximate impact relation of Hunter, the effects of impact in motion are also taken into consideration. The results indicated that after 3 s and under constant, linear, second-order and sinusoidal forces, the elliptic nanoparticle moves, respectively, less than 0.08 µm, 0.1143 µm, 0.36 µm and 25 nm. In addition, the results of cubic nanoparticles nanomanipulation show that the cubic nanoparticle moves less than 0.08 µm in 3 s under constant force scheme. This type of nanoparticle does not move when acted upon by a linear force along the Z-axis, while it shows a displacement of 0.0117 µm along the Y -axis. After the same 3 s, it moves about 0.37 µm and less than 25 nm under second-order and sinusoidal forces, respectively. [ABSTRACT FROM AUTHOR]

Introducing Nanotechnology course with extensive lab experiments to engineering students becomes essential during their undergraduate studies. It is believed that Nanotechnology should be defined in a specific track within the undergraduate engineering curriculum. The current practice shows several universities adopting this course but with different approaches. The paper exhibits two new instruments designed to support micro/nano-technology education for engineering students. An integrated nano-manipulator and micro-machining instruments have been designed with various operations to allow more capabilities offered to students to acquire hands-on experience in labs. The students' activities are planned to follow a planned set of units describing experimental activities and designed for the students as a roadmap for a couple of weeks, or the students' ideas as free access after a training. With integrated functions, the instruments would allow more freedom to students to explore and investigate their curiosity. [ABSTRACT FROM AUTHOR]

Nanotechnology has been considered with the aim of recognizing the structural and mechanical properties as well as improving the treatment and diagnostic process in the field of medicine. The process of nanomanipulation by examining healthy and cancerous tissues in nanoscale is one of the processes used in this field. Therefore, in this article, considering the importance of recognizing the properties of cancerous and healthy tissues in improving the treatment and diagnosis process, one of the most common types of cancer has been studied. Young modulus has been used as a parameter in the diagnosis of cancerous tissue and its value has been calculated for gastric cancerous tissue. To achieve this goal, atomic force microscopy (AFM) was used during the manipulation process. This tool with the ability to study cancerous tissues in different environments and with the least amount of damage to the target tissue, is one of the effective tools in the field of nanomanipulation. The parameter studied in this study is the geometry of gastric cancer tissue. Therefore, the simulations have been performed by considering contact models with spherical, cylindrical and crowned rollers geometries. The force-indentation depth diagram for gastric tissue is plotted experimentally and compared with theoretical results. According to the experimental work done after reviewing the recorded topographic images, the approximate range of the Young's modulus value for gastric tissue has been calculated according to different geometries. Since the geometry of the crowned rollers is closer to the geometry of the gastric tissue, it has a higher accuracy and the values of the Young's modulus have been calculated according to this geometry in the range of 316-310 KPa., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)

Nanoelectromechanical systems (NEMS) have been utilized as sensitive mass sensors in many applications such as single cell characterization, volatile organic biomarker detection and single molecule mass spectrometry. Using the frequency shift detection, mass of single analytes can be resolved. Mass detection sensitivity can be further improved by accurate measurement of the position, unlocking extra capabilities in nanoscale positioning and manipulation applications. Here, we studied the position sensing performance of two-mode NEMS resonators during detection of single 20 nm gold nanoparticles (GNPs). By recording the position of each particle with frequency shift sensing, the position detection accuracy was evaluated for different beam models and the results are validated by SEM imaging our results indicate that the position sensing accuracy, and therefore the mass sensing accuracy, of nanomechanical resonators depends critically on the use of appropriate beam models.

Recently, Ti-Ni based intermetallic alloys with shape memory effect (SME) have attracted much attention as promising functional materials for the development of record small nanomechanical tools, such as nanotweezers, for 3D manipulation of the real nano-objects. The problem of the fundamental restrictions on the minimal size of the nanomechanical device with SME for manipulation is connected with size effects which are observed in small samples of Ti-Ni based intermetallic alloys with thermoplastic structural phase transition from austenitic high symmetrical phase to low symmetrical martensitic phase. In the present work, by combining density functional theory and molecular dynamics modelling, austenite has been shown to be more stable than martensite in nanometer-sized TiNi wafers. In this case, the temperature of the martensitic transition asymptotically decreases with a decrease in the plate thickness h, and the complete suppression of the phase transition occurs for a plate with a thickness of 2 nm, which is in qualitative agreement with the experimental data. Moreover, the theoretical values obtained indicate the potential for even greater minimization of nanomechanical devices based on SME in TiNi.