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In this research, we investigate the propagation characteristics of Laguerre-Whittaker-Gaussian beams (LWGBs) through a paraxial ABCD optical system. We get the analytical expression for LWGBs using the Huygens-Fresnel integral. We then use this formula to study the propagation properties of a fractional Fourier transform (FRFT) optical system. Numerous aspects influencing the evolution of LWGBs in FRFT are investigated in detail, and their characteristics are illustrated graphically with numerical examples. The findings show that the initial LWGBs parameters (m, l, and n), fractional order p, and focal length f all impact the intensity and phase distributions of LWGBs, which vary regularly throughout propagation. These results might find applications in optical micromanipulation, remote sensing, and free-space optical communications. [ABSTRACT FROM AUTHOR]

Based on the Collins formula and the moment's method, the analytical expressions for the beam field propagation through an ABCD system, the beam propagation factor (M2-factor) and the kurtosis factor of a vortex higher-order cosine-hyperbolic-Gaussian beam (vHOChGB) are derived. It is shown that the propagation characteristics are determined by the beam structure parameters, such as the decentered parameter b, the cosh order N and the topological charge m. The kurtosis parameter is dependent, besides the structure beam parameters, on the propagation distance. Numerical examples are presented to discuss the influence of the parameters b, N and m on the propagation characteristics of vHOChGB in free space. This research may be beneficial to the applications involving vortex beams in optical communications, beam splitting, and micromanipulation of particles. [ABSTRACT FROM AUTHOR]

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While many micromanipulators offer advanced functionality, they often require relatively high power (10–100 mW) for actuation and are not easily integrated into existing diagnostic systems like endoscopes. This work presents an optically controlled fiber‐tip microgripper, which combines the light‐guiding capability of an optical fiber with the photoactuation of an azobenzene liquid crystal polymer. This microgripper opens and closes its fingers (polymer strips) using visible light at power levels as low as ≈0.3 mW and retains its shape without continuous illumination, providing notable energy efficiency. It is demonstrated to grasp, transport, and release a piece of optical fiber, a relatively heavy micro‐object. The use of a fiber to tether the microgripper and deliver pump light enables micromanipulation in narrow, hard‐to‐reach locations where external illumination may be impractical. Its compact design, low power consumption, and fiber‐optic compatibility position this microgripper—and its potential variants—as a promising tool for robotic, biomedical, and microfluidic applications. [ABSTRACT FROM AUTHOR]

Biological specimens exhibit significant variations in size and shape, challenging autonomous robotic manipulation. We focus on the mouse skull window creation task to illustrate these challenges. The study introduces a microscopic stereo camera system (MSCS) enhanced by the linear model for depth perception. Alongside this, a precise registration scheme is developed for the partially exposed mouse cranial surface, employing a CNN-based constrained and colorized registration strategy. These methods are integrated with the MSCS for robotic micromanipulation tasks. The MSCS demonstrated a high precision of $ 0.10\,{\rm mm} \pm 0.02\,{\rm mm} $ 0.10 mm ± 0.02 mm measured in a step height experiment and real-time performance of 30 FPS in 3D reconstruction. The registration scheme proved its precision, with a translational error of $ 1.13\,{\rm mm} \pm 0.31\,{\rm mm} $ 1.13 mm ± 0.31 mm and a rotational error of $ 3.38^\circ \pm 0.89^\circ $ 3.38 ∘ ± 0.89 ∘ tested on 105 continuous frames with an average speed of 1.60 FPS. This study presents the application of a MSCS and a novel registration scheme in enhancing the precision and accuracy of robotic micromanipulation in scientific and surgical settings. The innovations presented here offer automation methodology in handling the challenges of microscopic manipulation, paving the way for more accurate, efficient, and less invasive procedures in various fields of microsurgery and scientific research. [ABSTRACT FROM AUTHOR]

This paper presents the design, modeling, and analysis of a new XYθ piezoelectric microstage with high amplification ratios and fully symmetrical structures. Through the reconfigurable assembly positions of piezoelectric actuators, the proposed microstage can provide multiple actuation modes and low translational parasitic motion. The microstage is devised using improved four-bar amplification mechanisms and parallelogram guiding mechanisms. Based on the matrix-based compliance modeling, static and dynamic models are obtained. The theoretical models are analyzed by finite element analysis (FEA). Finally, a prototype of the proposed microstage is manufactured, an experimental system is set up, and the performance of the microstage is tested. The experimental results show that the microstage has amplification ratios of 8.40 (x-axis) and 8.52 (y-axis). The displacement coupling ratios in the x- and y-axis directions are 0.83% and 0.94%, respectively. Moreover, the maximum rotation angle is ± 2379.18 μrad when the microstage uses the actuation mode of the pure center rotation. The XYθ microstage is capable of multiscale micromanipulation. [ABSTRACT FROM AUTHOR]

Hydrogel‐based 3D cell cultures are extensively utilized to create biomimetic cellular microstructures. However, there is still lack of effective method for both evaluation of the complex interaction of cells with hydrogel and the functionality of the resulting micro‐structures. This limitation impedes the further application of these microstructures as microphysiological models (microPMs) for the screening of potential culture condition combinations to enhance the skeletal muscle regeneration. This paper introduces a two‐probe micromanipulation method for the large‐scale assessment of viscoelasticity and contractile force (CF) of skeletal muscle microPMs, which are produced in high‐throughput via microfluidic spinning and 96‐well culture. The collected data demonstrate that viscoelasticity parameters (E* and tanδ) and CF both measured in a solution environment are indicative of the formation of cellular structures without hydrogel residue and the subsequent generation of myotubes, respectively. This study have developed screening criterias that integrate E*, tanδ, and CF to examine the effects of multifactorial interactions on muscle fiber repair under hypoxic conditions and within bioprinted bipennate muscle structures. This approach has improved the quality of hypoxic threshold evaluation and aligned cell growth in 3D. The proposed method is useful in exploring the role of different factors in muscle tissue regeneration with limited resources. [ABSTRACT FROM AUTHOR]

Genome editing is recognized as a powerful tool in agriculture and research, enhancing our understanding of genetic function, diseases, and productivity. However, its progress in buffaloes has lagged behind other mammals due to several challenges, including long gestational periods, single pregnancies, and high raising costs. In this study, we aimed to generate MSTN-edited buffaloes, known for their distinctive double-muscling phenotype, as a proof of concept. To meet our goal, we used somatic cell nuclear transfer (SCNT) and zygotic electroporation (CRISPR-EP) technique. For this, we firstly identified the best transfection method for introduction of RNP complex into fibroblast which was further used for SCNT. For this, we compared the transfection, cleavage efficiency and cell viability of nucleofection and lipofection in adult fibroblasts. The cleavage, transfection efficiency and cell viability of nucleofection group was found to be significantly (P ≤ 0.05) higher than lipofection group. Four MSTN edited colony were generated using nucleofection, out of which three colonies was found to be biallelic and one was monoallelic. Further, we compared the efficacy, embryonic developmental potential and subsequent pregnancy outcome of SCNT and zygotic electroporation. The blastocyst rate of electroporated group was found to be significantly (P ≤ 0.05) higher than SCNT group. However, the zygotic electroporation group resulted into two pregnancies which were confirmed to be MSTN edited. Since, the zygotic electroporation does not require complex micromanipulation techniques associated with SCNT, it has potential for facilitating the genetic modification in large livestock such as buffaloes. The present study lays the basis for inducing genetic alternation with practical or biological significance. • Genome editing is a well-known method for introducing targeted genetic alterations into livestock genomes, however its progress in buffaloes has lagged behind. • In the present study, we aimed to generate MSTN-edited buffaloes using SCNT and Zygotic electroporation. • The best transfection method was identified for introduction of RNP complex into buffalo fibroblast which was further used for single cell isolation and generation of MSTN edited embryos via SCNT. • The embryonic developmental potential and subsequent pregnancy outcome of SCNT and zygotic electroporation were compared. [ABSTRACT FROM AUTHOR]

In biological micromanipulation, cell penetration is a typical procedure that precedes cell injection or oocyte enucleation. During this procedure, cells usually undergo significant deformation, which leads to cell damage. In this paper, we focus on modeling and evaluating the cell penetration process to reduce cell deformation and stress, thereby reducing cell damage. Initially, a finite element model (FEM) is established to simulate the cell penetration process. The effectiveness of the model is then verified through visual detection and comparison of cell deformation with experimental data. Next, various mechanical responses are analyzed, considering the influence of parameters, such as the radius and shape of the injection micropipettes, material properties, and size of the cells. Finally, the relationship between the intracellular stress and the cell penetration depth of biological cells is obtained. The evaluation results will be applied to develop optimized operation plans, enhancing the efficiency and safety of the cell penetration process. [ABSTRACT FROM AUTHOR]

Optical manipulation technology encompasses a suite of micromanipulation techniques that employ light to control and actuate microscopic objects. As a valuable scientific tool, optical manipulation technology is employed by researchers to investigate fundamental biological processes, examine the mechanics of microstructures, and develop innovative technologies with applications in diagnostics, imaging, and micro‐scale manufacturing. The rapid development of optical manipulation technology, combined with advanced microfabrication techniques, has catalyzed the emergence of a burgeoning research domain termed optically‐driven micromachinery. This rapidly expanding field has garnered significant research interest in recent years, fostering interdisciplinary collaboration across advanced manufacturing, materials science, biotechnology, and micro‐electromechanical systems. The capability to optically manipulate and control micromachines also opens new avenues for the development of advanced tools, sensors, and devices with enhanced functionalities, enabling the accomplishment of tasks previously considered impossible. This review presents a systematic overview of two important optical micromanipulation technologies, optical tweezers and optoelectronic tweezers, with focus on their applications in the field of optically‐driven micromachinery. A comparative analysis of optical tweezers and optoelectronic tweezers is conducted, accompanied by a discussion on strategies to further enhance their performance, paving the way for the development of more advanced and powerful optically‐driven micromachinery in the future. [ABSTRACT FROM AUTHOR]

Owing to the ability to parallel manipulate micro-objects, dynamic holographic optical tweezers (HOTs) are widely used for assembly and patterning of particles or cells. However, for simultaneous control of large-scale targets, potential collisions could lead to defects in the formed patterns. Herein we introduce the artificial potential field (APF) to develop dynamic HOTs that enable collision-avoidance micro-manipulation. By eliminating collision risks among particles, this method can maximize the degree of parallelism in multi-particle transport, and it permits the implementation of the Hungarian algorithm for matching the particles with their target sites in a minimal pathway. In proof-of-concept experiments, we employ APF-empowered dynamic HOTs to achieve direct assembly of a defect-free 8 × 8 array of microbeads, which starts from random initial positions. We further demonstrate successive flexible transformations of a 7 × 7 microbead array, by regulating its tilt angle and inter-particle spacing distances with a minimalist path. We anticipate that the proposed method will become a versatile tool to open up new possibilities for parallel optical micromanipulation tasks in a variety of fields. [ABSTRACT FROM AUTHOR]

Cell micromanipulation is an important technique in the field of biomedical engineering. Microgrippers play a crucial role in connecting macroscopic and microscopic objects in micromanipulation systems. However, since the operated biological cells are deformable, vulnerable, and typically distributed in sizes ranging from micrometers to millimeters, it poses a huge challenge to microgripper performance. To solve this problem, this paper develops a dual-driven piezoelectric microgripper with a high displacement amplification ratio, large stroke, and parallel gripping. By adopting modular configuration, three kinds of flexure-based mechanisms, including the lever mechanism, Scott–Russell mechanism, and parallelogram mechanism are connected in series to realize three-stage amplification, which effectively makes up for the shortage of small output displacement of the piezoelectric actuator. At the same time, the use of the parallelogram mechanism also isolates the parasitic rotation movement, and realizes the parallel movement of the gripping jaws. In addition, the kinematics, statics, and dynamics models of the microgripper are established by using the pseudo-rigid body and Lagrange methods, and the key geometric parameters are also optimized. Finite element simulation and experimental tests verify the effectiveness of the developed microgripper. The results show that the developed microgripper allows an amplification ratio of 46.4, a clamping stroke of 2180 μ m, and a natural frequency of 203.1 Hz. Based on the developed microgripper, the nondestructive micromanipulation of zebrafish embryos is successfully realized. [ABSTRACT FROM AUTHOR]

Bubble-based microfluidics has been applied in many fields. However, there remains a need for a facile and flexible method for stable bubble generation and control in a microchannel. This paper reports a hypersonic acoustic system that can generate and release functional stable bubbles in a microchannel in an on-demand manner. It was found that the hypersonic frequency in this system played a vital role in the generation and control of bubbles. Specifically, a nanostructurally enhanced acoustic resonator was used to generate highly localized ultrahigh-frequency acoustic waves that ensured the feasibility and rapidity of bubble generation. Simultaneously, the acoustothermal effect of hypersound was harnessed to effectuate precise control over the bubble size. In addition, high-throughput droplet splitting was performed to confirm the stability of bubbles and their functionality in micromanipulation. The results showed that a mother droplet could be split controllably into a desired number of daughter droplets with specific volume ratios. In summary, the hypersonic acoustic system was demonstrated to be capable of on-demandgeneration of stable bubbles in a microfluidic context and thus may extend the bubble-based applications. [ABSTRACT FROM AUTHOR]

Untethered magnetic soft robots show great potential for biomedical and small-scale micromanipulation applications due to their high flexibility and ability to cause minimal damage. However, most current research on these robots focuses on marine and reptilian biomimicry, which limits their ability to move in unstructured environments. In this work, we design a quadruped soft robot with a magnetic top cover and a specific magnetization angle, drawing inspiration from the common locomotion patterns of quadrupeds in nature and integrating our unique actuation principle. It can crawl and tumble and, by adjusting the magnetic field parameters, it adapts its locomotion to environmental conditions, enabling it to cross obstacles and perform remote transportation and release of cargo. [ABSTRACT FROM AUTHOR]

Field-controlled micromanipulation represents a pivotal technique for handling microparticles, yet conventional methods often risk physical damage to targets. Here, we discovered a completely new mechanism for true noncontact manipulation through photothermal effects, called thermal-optical tweezers. We employ a laser self-assembly photothermal waveguide (PTW) for dynamic microparticle manipulation. This waveguide demonstrates superior photothermal conversion and precision control, generating a nonisothermal temperature field. The interaction of thermal convection and thermophoresis within this field creates a microfluidic potential well, enabling noncontact and nondestructive particle manipulation. By varying the path of PTWs in lithography and manipulating laser loading modes, diverse manipulation strategies, such as Z-shaped migration, periodic oscillation, and directional transport, are achievable. Our innovative noninvasive micromanipulation technology minimizes not only physical damage to target objects but also enables precise and diverse manipulation of micro entities, opening up new avenues for the photothermal control of cells and biomolecules. [ABSTRACT FROM AUTHOR]

Loading individual oocytes is a critical step for injecting RNA, expressing heterologous proteins, performing electrophysiological measurements, and so on. However, existing methods remain a challenge for automatically loading multiple single oocytes into different locations. Herein, a novel microfluidic chip on a robotic manipulator (chip‐on‐robot) with feedback control for flexible manipulation of multiple oocytes within a large spatial range is proposed. The manipulator automatically controls the microfluidic chip to reach different locations based on imaging feedback. The microfluidic chip then utilizes the hydrodynamic focusing effect of the main channel to separate oocytes for individual loading or reloading under capacitive sensor feedback. The separation distance reaches approximately 16 times the oocyte diameter. Moreover, capacitive signal feedback on the number of oocytes for flow direction control ensures the separation of all oocytes. For close‐loop control of the loading/reloading process, image‐based oocyte detection is combined using deep learning to calculate the target position of the oocyte. Finally, an automatic sequence is achieved to load multiple single oocytes into a well chip by using the chip‐on‐robot. As a demonstration, the oocytes are reloaded into a specified location based on the conditions. The proposed chip‐on‐robot with feedback control has significant advantages in the micromanipulation of oocytes. [ABSTRACT FROM AUTHOR]

Dexterity micromanipulation is a significant topic in the field of robotics. Herein, a novel robotic rotating microjoint controlled by an exogenous magnetic field based on magnetic programmable soft materials, which brings more dexterity to the micromanipulation task is proposed. First, the magnetic soft material is synthesized and the microjoint is manufactured. The maximum rotation angle and response time are characterized. Then the force analysis of the microjoint in a uniform magnetic field is performed and the relationship between the deformation bending angle of a microjoint and the magnetic field magnitude is first proposed. A sliding mode controller based on the deformation mechanism of microjoints and radial basis function neural network (DMRSMC) is proposed to achieve robust deformation control of the microjoint. The experiment that depicts the microjoint is able to achieve a maximum rotation angle of 22.16° and a response time of 16 ms. The DMRSMC controller performs angle control with higher accuracy than conventional SMC and PID controllers. Finally, a dexterous suction mechanism is developed by combining the microjoint with a soft micropipette needle to achieve dexterous grasping of zebrafish embryos with a 97% success rate and an orientation adjustment error is 1.36°. [ABSTRACT FROM AUTHOR]

Exploring and taming the diffraction phenomena and divergence of light are foundational to enhancing comprehension of nature and developing photonic technologies. Despite the numerous types of nondiffraction beam generation technologies, the 3D deformation and intricate wavefront shaping of structures during propagation have yet to be studied through the lens of nanophotonic devices. Herein, the dynamic conversion of a circular Airy beam (CAB) to a Bessel beam with a single‐layer spin‐selective metasurface is demonstrated. This spatial transformation arises from the interplay of 1D local and 2D global phases, facilitating the 3D control of non‐diffractive light fields. An additional overall phase gradient and orbital angular momentum are introduced, which effectively altering the propagation direction and transverse fields of complex amplitude beams along the optical path. The manifested samples exhibit superior defect resistance, laying a crucial application in micro/nanolithography technologies. This approach expands the in‐plane spin‐selective mechanism and leverages the out‐of‐plane propagation dimension, allowing for integrated high‐resolution imaging, on‐chip optical micromanipulation, and micro/nanofabrication within a versatile nanophotonic platform. [ABSTRACT FROM AUTHOR]

Microgrippers offer better operational flexibility in biological micromanipulation. However, they face challenges in size miniaturization and environmental adaptability (especially in biological liquid environments). To overcome these challenges, a novel pneumatic microgripper is proposed with a thin-walled multi-airbag structure that directly drives the clamping jaws in motion, with a simple and compact overall construction. The microgripper has a maximum clamping range of 925 μm and can provide a clamping force exceeding 25 mN, capable of lifting loads over 300 times its weight. The microgripper is integrative and can be mass-produced with biocompatible resins in a single-step high-precision 3D printing process. The pneumatic microgripper is utilized to achieve the sorting and assisted injection of mouse oocytes (60–80 μm), assisted cutting of porcine oocytes (100–120 μm), and microscopic threading (10–15 μm) operation with two-finger cooperation. These demonstrations confirm it can operate fine manipulation of microscopic biological structures in air and liquid, and has good biocompatibility and cooperative operational ability. The developed pneumatic microgripper shows broad application prospects in biomedical applications such as microsurgery, micro biopsy, and assisted reproduction. [Display omitted] • A structurally integrated pneumatic microgripper is proposed for fine biological micromanipulation. • Micromanipulations of tiny biological structures are performed in air and liquid. • Innovative structural design enables a small structure while combining a large clamping range and high clamping force. • The microgripper is fabricated in a single-step high-precision 3D printing process. [ABSTRACT FROM AUTHOR]

Microgripper is a small‐miniaturized robotic device employed to maneuver sub‐millimeter‐sized particles or objects that are too small to be manipulated by human hands or conventional tools. The design and fabrication of the microgripper pose challenges due to the integration of actuation components into their structure. To address this challenge, the authors in this work presented a novel magnetic microgripper wherein the functions of the actuation components are executed by the two pairs of microgripper arms made up of magnetic material. A custom‐made electromagnetic system consisting of eight coils is employed to externally control these arms, enabling precise execution of gripping up to a maximum of two microparticles per working cycle. By varying the magnetic field strength from 20 to 120 mT, a wide range of gripper‐arms opening distance is achieved, spanning from 0.3 to 1.3 mm. Consequently, the microgripper is demonstrated to grip different sizes of microparticles ranging from 0.3 to 1.2 mm. As part of the motion control capabilities, the microgripper is demonstrated to orient and navigate across a 360‐degree range within the microfluidic environment. The presented microgripper holds promise for manipulating a wide variety of microparticle sizes and shapes, offering potential for high‐throughput applications [ABSTRACT FROM AUTHOR]

Spin‐orbital angular momentum conversion (SOC) of light has found applications in classical and quantum optics. However, the existing SOC elements suffer severe restrictions on broadband integrated applications at miniature scales, due to bulky configurations, single function, and failing to control the dispersion. Herein, a high‐efficiency broadband achromatic method for independently and elaborately engineering the dispersion and the SOC of light based on a cascaded metasurface device is proposed. The metadevice is capable of efficiently decoupling the SOC from the modulation of dispersion with high‐broadband focusing efficiency up to 75%. For the proof of concept, the generation of high‐efficiency achromatic‐focused and spin‐controlled optical vortices with switchable topological charge (lσ=+1=1$l^{\sigma = + 1} = 1$ and lσ=−1=2$l^{\sigma = - 1} = 2$) is successfully demonstrated. The presence of achromatically and highly concentrated optical vortices with tunable photonic angular momentum using spin as an optical knob makes the proposed ultracompact and multifunctional metadevice a promising platform for optical micromanipulation at nanoscale dimensions. [ABSTRACT FROM AUTHOR]

Acoustofluidic micromanipulation is an important tool for biomedical research, where acoustic forces offer the ability to manipulate fluids, cells, and particles in a rapid, biocompatible, and contact-free manner. Of particular interest is the investigation of acoustically driven sharp edges, where high tip velocity magnitudes and strong acoustic potential gradients drive rapid motion. Whereas prior devices utilizing 2D sharp edges have demonstrated promise for micromanipulation activities, taking advantage of 3D structures has the potential to increase their performance and the range of manipulation activities. In this work, we investigate high-magnitude acoustic streaming fields in the vicinity of sharp-edged, sub-wavelength 3D microstructures. We numerically model and experimentally demonstrate this in fabricating parametrically configured 3D microstructures whose tip-angle and geometry influence acoustic streaming velocities and the complexity of streaming vortices, finding that the simulated and realized velocities and streaming patterns are both tunable and a function of microstructure shape. These sharp-edge interfaces hold promise for biomedical studies benefiting from precise and targeted micromanipulation. [ABSTRACT FROM AUTHOR]

In this work, we investigate the generation of optical vortices with the radial-phase shift spiral zone plate from a flat-topped beam. Based on the process of the extended Huygens-Fresnel integral, an analytical formulation of the field distribution for the generated beam is developed. The evolution of the intensity distribution of the diffracted beam is numerically illustrated by studying the effects of some parameters. It is established that the characteristics of the intensity of the generated beam is increased with the beam waist, on the contrary, this intensity is decreased by the augmentation of the beam order N. Furthermore, it is demonstrated that in the topological charge equal to zero, the behavior of the beam is converted into a fundamental Gaussian. However, it is found that, for the topological charge superior to zero we have a vortex beam. In addition, it can be noted that the increase of the beam order leads the dark part size becomes large. In addition, as the shifting parameter is increased, the lobes appear larger. Finally, this research may be useful in different applications such as in optical switches and micromanipulation. [ABSTRACT FROM AUTHOR]

Manipulating micro/nanoparticles on deformed liquid interfaces induced by radiation pressure presents an active, non‐invasive, and contactless method. However, a significant challenge arises due to the relatively small magnitude of the radiation force in normal incidence. Nevertheless, this technique holds immense utility in controlling particle movement at interfaces, with numerous applications in both physical and biological contexts. To overcome this, the peculiar properties of total internal reflection (TIR) in retro‐reflection mode are expoited to create a ≈1μm$\approx \ 1\nobreakspace \umu m$ high amplitude bulge on the water surface, which can migrate 2μm$2\nobreakspace \umu m$ radius particles as forcibly as the traditional micro‐post paradigm. The bulge height is measured using an interferometric technique, and the underlying physics are demonstrated using an imitated particle with a capillary charge. By shining two pump lasers, an interface shape is created with increasing complexity, and the relative pump laser intensity is tuned to migrate particles in the desired direction. The method provides a non‐invasive and contactless way to remotely actuate almost all types of micro/nanoparticles at the liquid surface. [ABSTRACT FROM AUTHOR]

In the past few decades, researchers have conducted extensive studies on cell micromanipulation methods. However, there has consistently been a lack of a micromanipulation system that excels in both precision and speed. Additionally, many of these methods rely on manual control, thus significantly reducing efficiency. In this paper, a robotized micromanipulation system employing a two-finger microhand is proposed. The microhand has a 3-DoF parallel mechanism driven by three piezoelectric actuators, enabling high-precision micromanipulation. Replacing the needle-tip end-effector with a hemispherical end-effector makes cell grasping easier and more stable. In addition, a vibration-based release method combined with gel coating is proposed to reduce the release difficulty caused by adhesion forces. Through multiple sets of experiments, we have determined the optimal grasping and releasing conditions while balancing precision, stability, and damage degree to cells. An automated cell assembly strategy based on microscopic visual feedback and pick-and-place path planning is proposed to achieve the robotized high-speed cell array. Hela cells were chosen as the operation objects, achieving a 95% success rate in grasping and a 97% success rate in releasing. A "T" letter array formed by cells was successfully assembled with an average grasp and release time of less than 0.8 s and an assembly accuracy of 4.5 μm for a single cell. This study holds significant implications for the fields of biology and medicine, presenting potential applications in tissue engineering. [ABSTRACT FROM AUTHOR]

Smart adhesives with the ability to rapidly switch, achieve high adhesion tuning ratios, and provide precise control hold tremendous potential in various fields ranging from micromanipulation to manufacturing. Despite significant progress, an efficient and robust adhesive switch remains a rarity. In this study, a design strategy for magnetically actuated adhesives that exhibit switchable adhesion between high and low levels exceeding 50 times is proposed. The non‐contact actuation of the magnetic field induces a pre‐designed deformation of the magnetic tentacles, resulting in both interface cracks at the adhesion interface and a push force on the target object. Consequently, the pull‐off force can be precisely adjusted according to the strength of the magnetic field. This proposed adhesive also exhibits ultrafast detachment (<1.0 s). Tentative experiments are conducted for transfer‐print technology and on‐demand detachment, which demonstrate the advantages of magnetically actuated adhesives in a non‐contact manner. The proposed strategy of switching adhesion may be particularly useful for practical applications that require highly precise and swiftly controlled movements. [ABSTRACT FROM AUTHOR]

We present an analytical method to achieve highly nonparaxial, azimuthally polarized structured beams that, when propagating through an absorbing stratified media, can assume in the last semi‐infinite layer approximately any desired longitudinal intensity pattern within spatial regions few times larger than the wavelength. The possibility of managing the properties of a highly nonparaxial beam under adverse conditions, such as multiple reflections in stratified structures and energy loss to the material media, may be of great importance in many different optical applications, like, trapping and micromanipulation, remote sensing, thin films, medical devices, medical therapies, and so on. [ABSTRACT FROM AUTHOR]

The space charge effect is important in free-electron devices and sometimes plays a key role. A vacuum-compatible micromanipulation platform was devised to study this effect in a diode structure while changing the width of the gap between the emitter and the collector in situ in the range of hundreds of micrometers to tens of micrometers. The current–voltage characteristics were found to upshift with a decrease in the interelectrode distance; the space charge-limited current increased by approximately two orders of magnitude when the interelectrode distance decreased from 550 to 50 μm. The simplicity of the parallel-plate structure enabled analysis based on one-dimensional emission and transport with the measurement results showing a good fit to the model by Longo combined with the Child–Langmuir theory. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a new laser beam called Bessel higher-order cosh-Gaussian (BHChG) beam and analyzed its propagation properties through a paraxial ABCD optical system. The analytical expression of the diffracted beam is derived based on the extended Huygens–Fresnel integral and some numerical examples of BHChG beam propagating in a free space, through a thin lens and a Fractional Fourier transform system are exposed. The results reveal that the behavior of the output BHChG beam is affected by the optical system and the source beam parameters. The propagation of some laser beams through a paraxial ABCD optical system is deduced as particular case from the present study such as the fundamental Gaussian beam, the Bessel-Gaussian beam, the cosh-Gaussian beam, the Bessel-cosh-Gaussian beam and the Higher-order-cosh-Gaussian beam. The outcomes can be helpful for free-space optical communication, remote sensing and optical micromanipulation. [ABSTRACT FROM AUTHOR]

Optical vortex lattices (OVLs) are gaining increased research attention owing to their unique features related to intensity and phase structure. Interference is a common method for generating an OVL. However, the topological charge (TC) of a single building block in an OVL is fixed and cannot be modulated, thereby limiting its applicability. This study entailed the use of phase multiplication to generate a high‐order OVL to facilitate the arbitrary modulation of its TC. The generated high‐order OVL exhibited the Talbot effect during transmission, and it transformed into a super‐honeycomb lattice at specific fractional Talbot lengths. In addition, an orbital angular momentum developed in the OVL; this has broad application prospects in optical micromanipulation. Further, a method for generating super‐honeycomb lattices is devised. The findings of this study enhances understanding of the Talbot effect and broaden the practical applicability of OVLs. [ABSTRACT FROM AUTHOR]

Aided by computer generated holography, holographic optical tweezers enable manipulation of particles and objects with exceptional versatility. The responsiveness of the manipulation is often hindered by the speed of holograph generation, especially when the number of manipulated objects is high. Here, we propose an optimized hologram generation method with an improved iterative algorithm utilizing parallel computation with graphic processing units. The algorithm requires fewer iterations to produce high-quality holograms than established methods, such as weighted Gerchberg–Saxton algorithm, leading to a responsive and stable micromanipulation. This method expands the capabilities of holographic optical tweezers and provides more responsive traps in micro-manipulation. [ABSTRACT FROM AUTHOR]

Single-cell microrobots are new microartificial devices that use a combination of single cells and artificial devices, with the advantages of small size, easy degradation and ease of manufacture. With externally driven strategies such as light fields, sound fields and magnetic fields, microrobots are able to carry out precise micromanipulations and movements in complex microenvironments. Therefore, single-cell microrobots have received more and more attention and have been greatly developed in recent years. In this paper, we review the main classifications, control methods and recent advances in the field of single-cell microrobot applications. First, different types of robots, such as cell-based microrobots, bacteria-based microrobots, algae-based microrobots, etc., and their design strategies and fabrication processes are discussed separately. Next, three types of external field-driven technologies, optical, acoustic and magnetic, are presented and operations realized in vivo and in vitro by applying these three technologies are described. Subsequently, the results achieved by these robots in the fields of precise delivery, minimally invasive therapy are analyzed. Finally, a short summary is given and current challenges and future work on microbial-based robotics are discussed. [ABSTRACT FROM AUTHOR]

Chromatin regulatory processes physically take place in the environment of the cell nucleus, which is filled with the chromosomes and a plethora of smaller biomolecules. The nucleus contains macromolecular assemblies of different sizes, from nanometer-sized protein complexes to micrometer-sized biomolecular condensates, chromosome territories, and nuclear bodies. This multiscale organization impacts the transport processes within the nuclear interior, the global mechanical properties of the nucleus, and the way the nucleus senses and reacts to mechanical stimuli. Here, we discuss recent work on these aspects, including microrheology and micromanipulation experiments assessing the material properties of the nucleus and its subcomponents. We summarize how the properties of multiscale media depend on the time and length scales probed in the experiment, and we reconcile seemingly contradictory observations made on different scales. We also revisit the concept of liquid-like and solid-like material properties for complex media such as the nucleus. We propose that the nucleus can be considered a multiscale viscoelastic medium composed of three major components with distinct properties: the lamina, the chromatin network, and the nucleoplasmic fluid. This multicomponent organization enables the nucleus to serve its different functions as a reaction medium on the nanoscale and as a mechanosensor and structural scaffold on the microscale. [ABSTRACT FROM AUTHOR]

This paper proposes a novel approach to visualize the fractional orbital angular amentum (OAM) flow of light fields at the example of the Lommel tornado wave (LoTW) along the propagation direction in free space. The novel approach that is based on the transverse intensity distributions of the LoTWs can be used to identify and quantify the fractional OAM. The energy that is continuously distributed flexibly is controlled via the asymmetry factor and topological charge. Furthermore, the OAM density on concentric rings and chiral paths is employed to demonstrate convincingly as a manifestation of the energy flow. Such beams are anticipated to find potential applications in optical communication and optical micromanipulation. [ABSTRACT FROM AUTHOR]

The propagation properties of a circular cosine-hyperbolic Gaussian beam (CiChGB) in a strongly nonlocal nonlinear media (SNNM) are theoretically investigated. Based on the Snyder-Michell model and Collins formula, the closed-form expressions of the complex amplitude, beam width, and curvature radius for an on-axis incident CiChGB in SNNM are derived, and their evolution behaviors are illustrated with numerical examples. It is demonstrated that a CiChGB evolves periodically in SNNM, similarly to a spatial breather, due to the interplay between the nonlinearity process and diffraction. The period of evolution and beam intensity pattern is closely dependent on the input power, initial beam parameters, and SNNM factor. Under the critical input power, the intensity distribution, width and curvature radius of the beam can keep invariant upon propagation, so the CiChGB behaves like a soliton. The research results could have potential applications in beam shaping, optical switch, and micromanipulation. [ABSTRACT FROM AUTHOR]

Introducing vortices into an Airy beam by the interference between the lobes of the Airy beam for the first time, the modulation of Airy vortices is experimentally and theoretically investigated by electromagnetically induced transparency (EIT) effect and changing the number of side lobes of the Airy beam. The formation and disappearance of vortices in Airy beams can be caused by changing the number of side lobes. The EIT effect can induce the movement of vortex phase singularity by regulating the intensities of lobes in Airy beams. However, changing the number of side lobes can change the energy distribution of the lobes through the energy flow due to the self‐healing of Airy beams, thus causing the displacement of vortex phase singularity. In addition, the simulation of the Poynting vector shows that the less the side lobes are blocked, the more energy can be retained in the main lobe and the unblocked side lobes, so that the overall shape of the Airy beam can be better maintained. Such studies provide a new method to acquire and adjust Airy vortex beams and can be applied in the realm of optical micromanipulation. [ABSTRACT FROM AUTHOR]

In the realm of automatic wire-traction micromanipulation systems, the alignment of the central axis of the coil with the rotation axis of the rotary stage can be a challenge, which leads to the occurrence of eccentricity during rotation. The wire-traction is conducted at a micron-level of manipulation precision on micron electrode wires; eccentricity has a significant impact on the control accuracy of the system. To resolve the problem, a method for measuring and correcting the coil eccentricity is proposed in this paper. First, models of radial and tilt eccentricity are established respectively based on the eccentricity sources. Then, measuring eccentricity is proposed by an eccentricity model and microscopic vision; the model is used to predict eccentricity, and visual image processing algorithms are used to calibrate model parameters. In addition, a correction based on the compensation model and hardware is designed to compensate for the eccentricity. The experimental results demonstrate the accuracy of the models in predicting eccentricity and the effectiveness of correction. The results show that the models have an accurate prediction for eccentricity that relies on the evaluation of the root mean square error (RMSE); the maximal residual error after correction was within 6 μm, and the compensation was approximately 99.6%. The proposed method, which combines the eccentricity model and microvision for measuring and correcting eccentricity, offers improved wire-traction micromanipulation accuracy, enhanced efficiency, and an integrated system. It has more suitable and wider applications in the field of micromanipulation and microassembly. [ABSTRACT FROM AUTHOR]

In this paper, we present the investigations of an aluminum micro-tweezer designed for micromanipulation applications. It includes design, simulation, fabrication, characterizations, and experimental measurements. Electro-thermo-mechanical FEM-based simulations using COMSOL Multiphysics were performed to describe the behavior of the micro-electro-mechanical system (MEMS) device. The micro-tweezers were fabricated in aluminum, as structural material, by surface micromachining processes. Experimental measurements were performed and compared with the simulation results. A micromanipulation experiment was performed using titanium microbeads from 10–30 µm to confirm the performance of the micro-tweezer. This study serves as further research regarding the using of aluminum as structural material for MEMS devices designated for pick-and-place operations. [ABSTRACT FROM AUTHOR]

In order to improve the positioning accuracy of the micromanipulation system, a comprehensive error model is first established to take into account the microscope nonlinear imaging distortion, camera installation error, and the mechanical displacement error of the motorized stage. A novel error compensation method is then proposed with distortion compensation coefficients obtained by the Levenberg–Marquardt optimization algorithm combined with the deduced nonlinear imaging model. The compensation coefficients for camera installation error and mechanical displacement error are derived from the rigid-body translation technique and image stitching algorithm. To validate the error compensation model, single shot and cumulative error tests were designed. The experimental results show that after the error compensation, the displacement errors were controlled within 0.25 μm when moving in a single direction and within 0.02 μm per 1000 μm when moving in multiple directions. [ABSTRACT FROM AUTHOR]

Featured Application: This functionalization is able to provide solutions in order to improve robotic nano- or micromanipulation. Non-contact positioning of micro-objects using electric fields has been widely explored, based on several physical principles such as electrophoresis, dielectrophoresis (DEP) or optical dielectrophoresis (ODEP), in which the actuation force is induced by an electric charge or an electric dipole placed in an electric field. In this paper, we introduce a new way to control charges in non-contact positioning of micro-objects using chemical functionalization (3-aminopropyl) triethoxysilane—APTES) able to localize charges on a substrate and/or on a micro-object. We demonstrate that this functionalization in a liquid with a low ionic strength is able to concentrate a significant amount of electric charges on surfaces generating an electric field over a long distance (about 10 microns), also called a large exclusion zone (EZ). A model is proposed and validated with electrostatic force measurements between substrate and microparticles (diameter up to 40 µm). We demonstrate that the magnitude of the force and the force range decrease rapidly when the ionic strength of the medium increases. Based on the proposed model, we show that this new way to localize charges on micro-objects may be used for non-contact positioning. [ABSTRACT FROM AUTHOR]

Microneedles, including dissolvable ones made from biocompatible and biodegradable materials, have been widely studied and can potentially be used for transdermal drug delivery, disease diagnosis (sampling), skin care, etc. Characterizing their mechanical properties is essential, as being mechanically strong enough to pierce the skin barrier is one of the most fundamental and crucial requirements for them. The micromanipulation technique was based on compressing single microparticles between two flat surfaces to obtain force and displacement data simultaneously. Two mathematical models had already been developed to calculate the rupture stress and apparent Young's modulus, which can identify variations of these parameters in single microneedles within a microneedle patch. In this study, a new model has been developed to determine the viscoelasticity of single microneedles made of hyaluronic acid (HA) with a molecular weight of 300 kDa loaded with lidocaine by using the micromanipulation technique to gather experimental data. The modelling results from the micromanipulation measurements suggest that the microneedles were viscoelastic and their mechanical behaviour was strain-rate dependent, which implies that the penetration efficiency of viscoelastic microneedles can be improved by increasing their piercing speed into the skin. [ABSTRACT FROM AUTHOR]

In precision micromanipulation tasks, operation accuracy and anti-disturbance performance of micromanipulators are critical. This paper presents anti-disturbance control for a piezo-driven micromanipulator with a non-minimum phase. The micromanipulator is constructed by mounting a flexible manipulator on a parallel positioning stage. The micromotion and dynamic behavior of the micromanipulator are analyzed. Then, an anti-disturbance control strategy combining H-infinity feedback control and disturbance observer-based control for a non-minimum phase is designed to reduce disturbances and ensure control accuracy. Finally, the experimental measurement and control system is built. The observed phenomena show that sinusoidal disturbances are almost eliminated and the overshoot of step disturbances is significantly reduced. In addition, the time for suppressing the step disturbance is shortened from 0.9 to 0.3 s. Experiments verify the viability of the anti-disturbance control strategy. [ABSTRACT FROM AUTHOR]

This study evaluates the effects of double cryopreservation and re-biopsy on embryo viability and clinical outcomes. Studies of interest were selected from an initial cohort of 1027 potentially relevant records retrieved. PubMed was systematically searched for peer-reviewed original papers identified by keywords and medical subject heading terms. Moreover, we elaborated the evidence tables for double cryopreservation and re-biopsy separately. Data were systematically extracted, focusing on live birth, survival, clinical pregnancy, and miscarriage rates. For each study, we identified absolute numbers (numerator and denominator) related to clinical outcomes. Finally, for each outcome, we calculated the percentage change between the control and study groups. Among studies on double cryopreservation, 13 out of 22 reported no effect on clinical outcomes, suggesting contradictory results. Similarly, findings on re-biopsy were controversial, with seven out of 12 studies showing negative effects on survival and clinical outcomes, while five reported no impact. In our analysis of the evidence tables, we observed a reduction in live birth rates of 22.2% and 39.3% in blastocysts undergoing double vitrification and re-biopsy, respectively. These findings suggest that repeated micromanipulations can impair embryo competence. Therefore, double cryopreservation and re-biopsy should be limited in the selected cases without other options by consulting patients about the possible harmful effects. [ABSTRACT FROM AUTHOR]

Acoustically actuated bubbles provide a versatile and non-invasive approach for manipulating microorganisms in fluid. However, the susceptibility of the bubble volume to environment and the complex intersecting vortices of the oscillation of hemispherical bubbles reduce the stability of micromanipulation of ellipsoid-like organisms. This study involves an on-chip rotational manipulation device for rotating ellipsoid-like organisms, which utilizes parallel microstreaming vortices that are generated with acoustically actuated semi-capsule-shaped bubbles. In addition, a relatively stable volume of the semi-capsule-shaped bubble with tolerances about 5 % is realized by adjusting the gas diffusion between the bubble and the gas channel. Characterized experiments using polystyrene particles of 10 μm demonstrate that two pairs of significant out-of-plane parallel microstreaming vortices can be generated near the short or long side of a semi-capsule-shaped bubble at acoustic driving frequencies of 11.23 kHz and 13.97 kHz, respectively. The vortices effectively induce rotation both for the spherical particles and the ellipsoid-like paramecia in fluid. Compared to oscillating hemispherical bubbles, acoustically actuated semi-capsule-shaped bubbles offer a more stable attitude of the rotation axis and even rotation velocity for paramecia. The acoustically actuated semi-capsule-shaped bubbles offer a label-free method for rotational manipulation of ellipsoid-like organisms, characterized by good stability, adaptability, and biocompatibility. [Display omitted] • Acoustic oscillating semi-capsule-shaped bubbles is adopted for stable rotational manipulation of ellipsoid-like organisms. • Remarkable parallel microstreaming vortices are generated with acoustically actuated semi-capsular-shaped bubbles. • Relatively stable attitude of the rotation axis and even rotation velocity are realized in rotating ellipsoid-like organisms. • The volume of bubble can be relatively stable by adjusting with relative gas pressure. [ABSTRACT FROM AUTHOR]

Precise acoustic micromanipulation is emerging as an important tool in biomedical research, where acoustic forces have the advantage of being contact‐free, label‐free, and biocompatible. Conventional acoustofluidic approaches, however, produce device‐scale effects that limit the ability to locally target acoustic energies at the microscale. In this study, we demonstrate an approach to generate designed and highly local acoustic fields using 3D resonant mass‐spring microstructures, achieving local acoustic field gradients on the order of microns, orders of magnitude smaller than the fluid wavelength. In doing so, rapid and spatially defined controllable micromanipulation, including particle capture, transport, and patterning using arbitrarily arranged micro‐resonator arrays is demonstrated. This sub‐wavelength, 3D acoustofluidic approach results in highly localized and defined micromanipulation, with potential applications across sample preparation, cell analysis, and diagnostics. [ABSTRACT FROM AUTHOR]

Purpose: To determine if deep learning artificial intelligence algorithms can be used to accurately identify key morphologic landmarks on oocytes and cleavage stage embryo images for micromanipulation procedures such as intracytoplasmic sperm injection (ICSI) or assisted hatching (AH). Methods: Two convolutional neural network (CNN) models were trained, validated, and tested over three replicates to identify key morphologic landmarks used to guide embryologists when performing micromanipulation procedures. The first model (CNN-ICSI) was trained (n = 13,992), validated (n = 1920), and tested (n = 3900) to identify the optimal location for ICSI through polar body identification. The second model (CNN-AH) was trained (n = 13,908), validated (n = 1908), and tested (n = 3888) to identify the optimal location for AH on the zona pellucida that maximizes distance from healthy blastomeres. Results: The CNN-ICSI model accurately identified the polar body and corresponding optimal ICSI location with 98.9% accuracy (95% CI 98.5–99.2%) with a receiver operator characteristic (ROC) with micro and macro area under the curves (AUC) of 1. The CNN-AH model accurately identified the optimal AH location with 99.41% accuracy (95% CI 99.11–99.62%) with a ROC with micro and macro AUCs of 1. Conclusion: Deep CNN models demonstrate powerful potential in accurately identifying key landmarks on oocytes and cleavage stage embryos for micromanipulation. These findings are novel, essential stepping stones in the automation of micromanipulation procedures. [ABSTRACT FROM AUTHOR]

This paper presents a typical grasp–hold–release micromanipulation simulator based on MATLAB and Simulink. Closed-loop force and position control were implemented only based on a camera. The work was mainly focused on control performance improvements and GUI design. Different types of control strategies were investigated in both the position and force control processes. Finally, incremental PID and positional PID were adopted in the gripper position control and force control processes, respectively. The best performance of the gripper position control was the fast response of 0.3 s without overshoot and steady-state errors in the range of 10–40 Hz. The new camera control algorithm kept a big motion range (4.48 × 4.48 mm) and a high position resolution of 0.56 µm, with a high force resolution of 1.56 µN in the force control stage. The maximum error between the measured force and the real force was maintained below 4 µN. The steady-state error and the setting time were less than 1.2% and less than 1.5 s, respectively. A separate app, the Image Generation Simulator app, was developed to assist users in getting suitable initial coordinates, camera parameters, desired position resolutions, and force resolutions, which are packed as a standalone executable file. The main app can run the simulation model, debug, playback, and report simulation results, and calculate the calibration equation. Different initial coordinates, camera parameters, sample frequencies, controller parameters, and even controller types can be adjusted from this app. [ABSTRACT FROM AUTHOR]

Since Y‐STR typing only amplifies male Y chromosomal DNA, it can simplify the interpretation of some DNA mixtures that contain female DNA. However, if there are multiple male contributors, mixed Y‐STR DNA profiles will often be obtained. Y‐STR mixture analysis cases are particularly challenging though as, currently, there are no validated probabilistic genotyping (PG) software solutions commercially available to aid in their interpretation. One approach to fully deconvoluting these challenging mixtures into their individual donors is to conduct single‐cell genotyping by isolating individual cells from a mixture prior to conducting DNA typing. In this work, a physical micromanipulation technique involving a tungsten needle and direct PCR with decreased reaction volume and increased cycle number was applied to equimolar 2‐ and 3‐person buccal cell male DNA mixtures and a mock touch DNA case scenario involving the consecutive firing of a handgun by two males. A consensus DNA profiling approach was then utilized to obtain YFiler™ Plus Y‐STR haplotypes. Buccal cells were used to optimize and test the direct single‐cell subsampling approach, and 2–3 person male buccal cell mixtures were fully deconvoluted into their individual donor Y‐STR haplotypes. Single‐cell (or agglomerated cell clump) subsampling from the gun's trigger recovered single‐source Y‐STR profiles from both individuals who fired the gun, the owner, and the other unrelated male. Only the non‐owner's DNA was found in the cells recovered from the handle. In summary, direct single‐cell subsampling as described represents a potential simple way to analyze and interpret Y‐STR mixtures. [ABSTRACT FROM AUTHOR]

Micromanipulation is a powerful technique to measure the mechanical properties of microparticles including microcapsules. For microparticles with a homogenous structure, their apparent Young's modulus can be determined from the force versus displacement data fitted by the classical Hertz model. Microcapsules can consist of a liquid core surrounded by a solid shell. Two Young's modulus values can be defined, i.e., the one is that determined using the Hertz model and another is the intrinsic Young's modulus of the shell material, which can be calculated from finite element analysis (FEA). In this study, the two Young's modulus values of microplastic-free plant-based microcapsules with a core of perfume oil (hexyl salicylate) were calculated using the aforementioned approaches. The apparent Young's modulus value of the whole microcapsules determined by the classical Hertz model was found to be EA = 0.095 ± 0.014 GPa by treating each individual microcapsule as a homogeneous solid spherical particle. The previously obtained simulation results from FEA were utilised to fit the micromanipulation data of individual core–shell microcapsules, enabling to determine their unique shell thickness to radius ratio (h/r)FEA = 0.132 ± 0.009 and the intrinsic Young's modulus of their shell (EFEA = 1.02 ± 0.13 GPa). Moreover, a novel theoretical relationship between the two Young's modulus values has been derived. It is found that the ratio of the two Young's module values (EA/EFEA) is only a function on the ratio of the shell thickness to radius (h/r) of the individual microcapsule, which can be fitted by a third-degree polynomial function of h/r. Such relationship has proven applicable to a broad spectrum of microcapsules (i.e., non-synthetic, synthetic, and double coated shells) regardless of their shell chemistry. [ABSTRACT FROM AUTHOR]