Precise Manipulation Research Articles

UNICOMPARTMENTAL KNEE ARTHROPLASTY: WHAT IS THE OPTIMAL ALIGNMENT CORRECTION TO ACHIEVE SUCCESS? THE ROLE OF KINEMATIC ALIGNMENT. STATE OFF THE ART REVIEW

Unicompartmental knee arthroplasty (UKA) is in many ways the ultimate kinematic operation as the express aim is to resurface the diseased side of the joint and restore pre-arthritic alignment and balance while maintaining integrity of both cruciate ligaments. An increasing body of knowledge relates the outcomes of UKA to pre-arthritic anatomy rather than an arbitrarily defined neutral. The Coronal Plane Alignment of the Knee (CPAK) classification provides a validated technique for calculating pre-arthritic limb alignment (the Arithmetic Hip-Knee-Ankle Ankle (aHKA)) and Joint Line Obliquity (JLO) and will enable a greater understanding of the interactions between pre-arthritic anatomy, choice of prosthetic position and outcomes. When pre-arthritic alignment is not taken into consideration a post-operative limb alignment of mild to moderate varus for medial UKA and moderate valgus for lateral UKA appears produces the best outcomes. When pre-arthritic anatomy is taken into account superior results have been reported with restoration of pre-arthritic limb alignment and joint line obliquity. Restriction boundaries have yet to be clearly defined for tibial component coronal and Hip-Knee-Ankle (HKA) angles when applying this new paradigm, but existing evidence would suggest a 60 varus limit for the tibial coronal angle may be a reasonable starting point. Lateral UKA has inherent differences in terms of tibial component positioning and ligament balance targets. Mobile bearing UKA demands a three-dimensional understanding of the effect of implant position on bearing stability. Modification of technique is necessary to produce anatomic tibia component angles with equipment designed for mechanical alignment. Robotic technology allows accurate understanding of pre-arthritic anatomy, precise reproduction of patient specific virtual planning, equally precise manipulation of soft tissue balance and future research using these platforms likely to further clarify in terms of ideal patient specific component and limb alignment targets.

Can nanotechnology and genomics innovations trigger agricultural revolution and sustainable development?

At the dawn of new millennium, policy makers and researchers focused on sustainable agricultural growth, aiming for food security and enhanced food quality. Several emerging scientific innovations hold the promise to meet the future challenges. Nanotechnology presents a promising avenue to tackle the diverse challenges in agriculture. By leveraging nanomaterials, including nano fertilizers, pesticides, and sensors, it provides targeted delivery methods, enhancing efficacy in both crop production and protection. This integration of nanotechnology with agriculture introduces innovations like disease diagnostics, improved nutrient uptake in plants, and advanced delivery systems for agrochemicals. These precision-based approaches not only optimize resource utilization but also reduce environmental impact, aligning well with sustainability objectives. Concurrently, genetic innovations, including genome editing and advanced breeding techniques, enable the development of crops with improved yield, resilience, and nutritional content. The emergence of precision gene-editing technologies, exemplified by CRISPR/Cas9, can transform the realm of genetic modification and enabled precise manipulation of plant genomes while avoiding the incorporation of external DNAs. Integration of nanotechnology and genetic innovations in agriculture presents a transformative approach. Leveraging nanoparticles for targeted genetic modifications, nanosensors for early plant health monitoring, and precision nanomaterials for controlled delivery of inputs offers a sustainable pathway towards enhanced crop productivity, resource efficiency, and food safety throughout the agricultural lifecycle. This comprehensive review outlines the pivotal role of nanotechnology in precision agriculture, emphasizing soil health improvement, stress resilience against biotic and abiotic factors, environmental sustainability, and genetic engineering.

Shape-Controlled Growth and In Situ Characterization of CdS Nanocrystals via Liquid Cell Transmission Electron Microscopy

Controlling the growth, structure, and shape of CdS nanocrystals is crucial for harnessing their unique physicochemical properties across diverse applications. This control can be achieved by introducing chemical additives into the synthesis reaction mixture. However, precise manipulation of nanocrystal synthesis necessitates a thorough understanding of the formation mechanisms under various chemical conditions, a task that remains challenging. In this study, we employed in situ liquid cell transmission electron microscopy (TEM) to investigate the growth mechanisms of CdS nanocrystals in a reaction solution of cadmium chloride and thiourea, with sodium citrate serving as a structure-directing agent. We observed that CdS nanocrystals evolve through two distinct growth modes: (1) in the absence of sodium citrate, spherical nanocrystals isotropically transform into CdS nanocubes, and (2) in the presence of sodium citrate, cuboid nanocrystals preferentially extend along the {011} direction and anisotropically into CdS triangular nanoplates. Theoretical analysis has confirmed that the adsorption energy of sodium citrate on different crystal facets significantly influences the morphology of the CdS nanocrystals. Our findings not only provide a method for synthesizing CdS nanocrystals based on electron beam induction but also elucidate the intricate nanoscale growth mechanisms, offering insights that could inform the future rational design of nanocrystals with tailored morphologies.

Impact of Polyploidy on Crop Improvement and Plant Breeding Strategies: A Review

Polyploidy, the condition of possessing multiple sets of chromosomes, is a widespread phenomenon in plants that has had a profound impact on crop evolution and improvement. This review explores the role of polyploidy in plant breeding strategies, emphasizing its contributions to enhancing agronomic traits, overcoming genetic barriers, and expanding genetic diversity. Polyploid crops, such as wheat, cotton, and Brassica species, exhibit superior yield, increased biomass, and enhanced stress tolerance compared to their diploid counterparts. Polyploidy can arise naturally or be induced artificially, providing breeders with opportunities to create novel crop varieties through synthetic polyploidization. The complexity of polyploid genomes poses significant challenges, including fertility issues, meiotic instability, and difficulties in genome management. Advances in genomic and biotechnological tools, such as genomic selection and CRISPR-based genome editing, are beginning to address these obstacles, allowing for precise manipulation of polyploid genomes and improved breeding outcomes. Additionally, polyploidy plays a crucial role in overcoming reproductive barriers in interspecific hybrids, facilitating the transfer of desirable traits between species that would otherwise be genetically incompatible. The potential of polyploidy for developing climate-resilient crops is particularly noteworthy, as polyploid plants often exhibit greater tolerance to drought, salinity, and extreme temperatures. This makes polyploid breeding a promising approach for addressing the challenges of climate change and ensuring food security. Future research should focus on understanding the genetic and epigenetic mechanisms underlying polyploid genome stability and trait expression, as well as integrating advanced computational tools to predict and manipulate polyploid gene function. Emerging areas such as synthetic biology and multi-omics integration will further enhance our ability to engineer polyploid crops with complex trait architectures. Polyploidy remains a powerful and versatile tool for plant breeders, offering immense potential for crop improvement, genetic innovation, and the development of resilient agricultural systems. As the understanding and technological capabilities in polyploid breeding continue to advance, polyploid crops will play a central role in sustainable agricultural development and global food production.

The Role of Biotechnology in Shaping the Future of Modern Agriculture

Biotechnology stands as a cornerstone in the evolution of modern agriculture, offering an array of innovative solutions poised to revolutionize crop productivity, enhance nutritional quality, and foster environmental sustainability. This comprehensive review delves into the multifaceted role of biotechnology in shaping the future landscape of agriculture, encompassing diverse realms such as genetic engineering, molecular breeding, and microbial biotechnology. Spanning from crop improvement to pest and disease management, soil health, and sustainable agriculture practices, the applications of biotechnology in agriculture are far-reaching and profound. Genetic engineering emerges as a powerful tool in the arsenal of agricultural biotechnology, facilitating the precise manipulation of plant genomes to confer desirable traits such as increased yield, enhanced nutritional content, and resistance to biotic and abiotic stresses. Molecular breeding techniques complement this approach, leveraging advances in genomics and bioinformatics to expedite the breeding process and develop high-performing crop varieties tailored to specific agroecological contexts, microbial biotechnology emerges as a pivotal force in sustainable agriculture, harnessing the power of beneficial microorganisms to improve soil fertility, enhance nutrient uptake, and suppress plant pathogens. From biofertilizers and biopesticides to bioremediation and phytoremediation, microbial-based solutions hold immense potential in mitigating environmental degradation and promoting agroecosystem resilience, the widespread adoption of biotechnology in agriculture is not devoid of societal, economic, and ethical considerations. Regarding food safety, environmental impact, and socio-economic equity underscore the need for rigorous regulatory frameworks and robust risk assessment protocols to ensure the responsible deployment of biotechnological innovations, public perceptions and fostering dialogue between stakeholders are essential for building trust and garnering support for biotechnology in agriculture. Education, transparency, and stakeholder engagement are paramount in navigating the complex terrain of biotechnology governance and fostering an enabling environment for innovation, the current state and future prospects of biotechnology in agriculture, this review endeavors to inform policymakers, researchers, and stakeholders about the transformative potential of biotechnology to address pressing global challenges such as food security, climate change, and environmental sustainability. Embracing the opportunities afforded by biotechnology holds the key to unlocking a more resilient, equitable, and sustainable agricultural future.

Controlling the orientation of ellipsoidal nanoparticles using fractional vector beams

In the field of nanotechnology, achieving precise manipulation of ellipsoidal nanoparticles presents a significant challenge because it requires controlling five degrees of freedom, including three spatial dimensions (position in 3D space) and two angular dimensions (polar and azimuthal angles). In this work, we investigate both the optical forces and trapping potentials on an ellipsoidal nanoparticle produced by tightly focused fractional vector beams (FVBs). Unlike the integer vector beams (IVBs), which manipulate only three spatial dimensions of ellipsoidal particles, FVB with an initial phase not only provides spatial position control but also enables precise manipulation of spatial orientation. Moreover, by adjusting the topological index and initial phase of the incident FVBs, arbitrary orientations in the 3D space of ellipsoidal nanoparticles can be achieved. Our results may find interesting applications in microfluidics, biomedical engineering, and nanotechnology.

ReaL-MGE is a tool for enhanced multiplex genome engineering and application to malonyl-CoA anabolism.

The complexities encountered in microbial metabolic engineering continue to elude prediction and design. Unravelling these complexities requires strategies that go beyond conventional genetics. Using multiplex mutagenesis with double stranded (ds) DNA, we extend the multiplex repertoire previously pioneered using single strand (ss) oligonucleotides. We present ReaL-MGE (Recombineering and Linear CRISPR/Cas9 assisted Multiplex Genome Engineering). ReaL-MGE enables precise manipulation of numerous large DNA sequences as demonstrated by the simultaneous insertion of multiple kilobase-scale sequences into E. coli, Schlegelella brevitalea and Pseudomonas putida genomes without any off-target errors. ReaL-MGE applications to enhance intracellular malonyl-CoA levels in these three genomes achieved 26-, 20-, and 13.5-fold elevations respectively, thereby promoting target polyketide yields by more than an order of magnitude. In a further round of ReaL-MGE, we adapt S. brevitalea to malonyl-CoA elevation utilizing a restricted carbon source (lignocellulose from straw) to realize production of the anti-cancer secondary metabolite, epothilone from lignocellulose. Multiplex mutagenesis with dsDNA enables the incorporation of lengthy segments that can fully encode additional functions. Additionally, the utilization of PCR to generate the dsDNAs brings flexible design advantages. ReaL-MGE presents strategic options in microbial metabolic engineering.

Enhanced Green Fluorescent Protein Streaming Dielectrophoresis in Insulator-Based Microfluidic Devices.

There is tantalizing evidence that proteins can be accurately and selectively manipulated by higher order electric field effects within microfluidic devices. The accurate and precise manipulation of proteins in these platforms promises to disrupt and revolutionize many fields, most notably analytical biochemistry. Several lines of experimental evidence suggest much higher forces are generated compared to those calculated from traditional theories and those higher forces arise from subtle structural features of the proteins providing selectivity. New theories reflect some of the experimental evidence in the magnitude of the force predicted and inclusion of subtle structural features absent in traditional continuum theory. Unfortunately, the experimental evidence is largely exploratory in nature and lacks one or more important elements that prevents a clear interpretation and comparison to not only the other existing data, but also quantitative comparison to the evolving theoretical descriptions. Here, a clear and interpretable experimental system is presented that quantitatively determines the dielectrophoretic susceptibility of unlabeled, unaggregated native-structure protein molecules that are exposed to modest electric fields (105-106V/m) for short periods of time (∼5ms) without significant increases in local concentration. The platform uses sub-nanogram quantities of protein, the probed volume upon determination is a few picoliters, and the total analysis time is 10 s.

Sodium-Selective Channelrhodopsins

Channelrhodopsins (ChRs) are light-gated ion channels originally discovered in algae and are commonly used in neuroscience for controlling the electrical activity of neurons with high precision. Initially-discovered ChRs were non-selective cation channels, allowing the flow of multiple ions, such as Na+, K+, H+, and Ca2+, leading to membrane depolarization and triggering action potentials in neurons. As the field of optogenetics has evolved, ChRs with more specific ion selectivity were discovered or engineered, offering more precise optogenetic manipulation. This review highlights the natural occurrence and engineered variants of sodium-selective channelrhodopsins (NaChRs), emphasizing their importance in optogenetic applications. These tools offer enhanced specificity in Na+ ion conduction, reducing unwanted effects from other ions, and generating strong depolarizing currents. Some of the NaChRs showed nearly no desensitization upon light illumination. These characteristics make them particularly useful for experiments requiring robust depolarization or direct Na+ ion manipulation. The review further discusses the molecular structure of these channels, recent advances in their development, and potential applications, including a proposed drug delivery system using NaChR-expressing red blood cells that could be triggered to release therapeutic agents upon light activation. This review concludes with a forward-looking perspective on expanding the use of NaChRs in both basic research and clinical settings.

Rotaxanes with a photoresponsive macrocycle modulate the lipid bilayers of large and giant unilamellar vesicles

Rotaxanes equipped with actuators hold great potential for developing highly functional molecular machines. Such systems could significantly enhance our ability to study and manipulate biological and artificial membranes. Here, we introduce a rotaxane with a ring featuring two azobenzene photoswitches, which retain their photoreversibility and can be stochastically shuttled along the axle in solution. Studies in model bilayers, supported by molecular dynamics simulations, show how azobenzene photoswitching alters the interaction of rotaxanes with surrounding lipids, leading to changes in lipid packing. Such changes in the lipid bilayer were leveraged to induce the light-triggered release of sulforhodamine B from large unilamellar vesicles. Additionally, light activation of the rotaxanes is shown to induce reversible contraction and expansion of giant unilamellar vesicles. The results provide novel insights into the interactions and operation of rotaxanes in lipid bilayers and their impact on membrane properties. This will aid in developing systems for precise membrane manipulation for applications in biomedicine and bioengineering.

Microfluidic Optical Aptasensor for Small Molecules Based on Analyte-Tuned Growth of Gold Nanoseeds and Machine Learning-Enhanced Spectrum Analysis: Rapid Detection of Mycotoxins.

Natural toxins, mainly small molecules, are a category of chemical hazards in agri-food systems that pose threats to both public health and food security. Current standard methods for monitoring these toxins, predominantly based on liquid chromatography-mass spectrometry, are costly, labor-intensive, and complex. This study presents the development of a novel microfluidic optical aptasensor for rapid detection of small molecules based on analyte-tuned growth of gold nanoseeds combined with machine learning-enhanced spectrum analysis. We discovered and optimized a previously unreported growth pattern of aptamer-coated nanoparticles in the presence of different concentrations of analyte, enabling the detection of a major mycotoxin in food. The entire analysis was miniaturized on a customized microfluidic platform, allowing for automated spectral acquisition with precise liquid manipulation. A machine learning model, based on random forest with feature engineering, was developed and evaluated for spectrum analysis, significantly enhancing the prediction of mycotoxin concentrations. This approach extended the detection limit determined by the conventional method (∼72 ppb with high variation) to a wider range of 10 ppb to 100 ppm with high accuracy (overall mean absolute percentage error of 5.7%). The developed analytical tool provides a promising solution for detecting small molecules and monitoring chemical hazards in agri-food systems and the environment.

Hydrogen Sulfide‐Triggered Artificial DNAzyme Switches for Precise Manipulation of Cellular Functions

AbstractThe development of synthetic molecular tools responsive to biological cues is crucial for advancing targeted cellular regulation. A significant challenge is the regulation of cellular processes in response to gaseous signaling molecules such as hydrogen sulfide (H2S). To address this, we present the design of Gas signaling molecule‐Responsive Artificial DNAzyme‐based Switches (GRAS) to manipulate cellular functions via H2S‐sensitive synthetic DNAzymes. By incorporating stimuli‐responsive moieties to the phosphorothioate backbone, DNAzymes are strategically designed with H2S‐responsive azide groups at cofactor binding locations within the catalytic core region. These modifications enable their activation through H2S‐reducing decaging, thereby initiating substrate cleavage activity. Our approach allows for the flexible customization of various DNAzymes to regulate distinct cellular processes in diverse scenarios. Intracellularly, the enzymatic activity of GRAS promotes H2S‐induced cleavage of specific mRNA sequences, enabling targeted gene silencing and inducing apoptosis in cancer cells. Moreover, integrating GRAS with dynamic DNA assembly allows for grafting these functional switches onto cell surface receptors, facilitating H2S‐triggered receptor dimerization. This extracellular activation transmits signals intracellularly to regulate cellular behaviors such as migration and proliferation. Collectively, synthetic switches are capable of rewiring cellular functions in response to gaseous cues, offering a promising avenue for advanced targeted cellular engineering.

Revolutionizing medicine: Recent developments and future prospects in stem-cell therapy.

Stem-cell therapy is a revolutionary frontier in modern medicine, offering enormous capacity to transform the treatment landscape of numerous debilitating illnesses and injuries. This review examines the revolutionary frontier of treatments utilizing stem cells, highlighting the distinctive abilities of stem cells to undergo regeneration and specialized cell differentiation into a wide variety of phenotypes. This paper aims to guide researchers, physicians, and stakeholders through the intricate terrain of stem-cell therapy, examining the processes, applications, and challenges inherent in utilizing stem cells across diverse medical disciplines. The historical journey from foundational contributions in the late 19th and early 20th centuries to recent breakthroughs, including ESC isolation and iPSC discovery, has set the stage for monumental leaps in medical science. Stem cells' regenerative potential spans embryonic, adult, induced pluripotent, and perinatal stages, offering unprecedented therapeutic opportunities in cancer, neurodegenerative disorders, cardiovascular ailments, spinal cord injuries, diabetes, and tissue damage. However, difficulties, such as immunological rejection, tumorigenesis, and precise manipulation of stem-cell behavior, necessitate comprehensive exploration and innovative solutions. This manuscript summarizes recent biotechnological advancements, critical trial evaluations, and emerging technologies, providing a nuanced understanding of the triumphs, difficulties, and future trajectories in stem cell-based regenerative medicine. Future directions, including precision medicine integration, immune modulation strategies, advancements in gene-editing technologies, and bioengineering synergy, offer a roadmap in stem cell treatment. The focus on stem-cell therapy's potential highlights its significant influence on contemporary medicine and points to a future in which individualized regenerative therapies will alleviate various medical disorders.

Twisted Metasurfaces for On‐Demand Focusing Localization

AbstractDynamic focusing of electromagnetic (EM) waves is a cornerstone in various applications, encompassing aerospace communication, sensing, and high‐resolution imaging. Recently, the advent of intelligent metasurfaces, hailed as the next evolutionary step, has revolutionized self‐adaptive functionalities. However, their extensive embeddings of active components pose a great challenge associated with escalated costs, heightened power consumption, and increased complexity, thus hindering large‐scale implementation. Here, a cost‐effective approach for dynamic EM focusing utilizing a twisted metasurface is introduced, which integrates a transmissive layer with a reflective layer in a cascade fashion. This innovative design leverages the mutual rotation between two layers to enable the precise manipulation of beam propagation and scanning area, allowing for the flexible localization of the focal point across a wide range, spanning −44.17° to 44.17° in elevation and 0° to 360° in azimuth. This capability is underpinned by the strategic fusion of multiple phase profiles, including gradient and Gaussian phase. In the experiment, a goal‐oriented system is built up whose outcomes demonstrate a striking alignment with the simulated results, achieving a correlation coefficient of 96.7%. This work presents a streamlined pathway toward dynamic EM focusing and the related applications constrained by space and power limitations.

Low-Energy Photoresponsive Magnetic-Assisted Cleaning Microrobots for Removal of Microplastics in Water Environments.

In the global ecosystem, microplastic pollution pervades extensively, exerting profound and detrimental effects on marine life and human well-being. However, conventional removal methods are usually limited to chemical flocculation and physical filtration but are insufficient to remove extremely small microplastics. Therefore, developing a comprehensive strategy to address the threat posed by microplastics is imperative. Here, we report a low-energy photoresponsive magnetic-assisted cleaning microrobot (LMCM) composed of photocatalytic material (Ag@Bi2WO6) and magnetic nanoparticles (Fe3O4), which can be used for the active removal of microplastics from water environments. Due to the diffusion electrophoresis effect, the low-energy photoresponsive cleaning microrobots (LCMs) are formed by spontaneous assembly of Ag@Bi2WO6, which can continuously adsorb microplastics in a water environment. Particularly, the effective attraction distance of LCMs on microplastics exceeds 100 μm. After assembling the Fe3O4 nanoparticles, LMCMs can clean microplastics in groups from water environments under the control of a magnetic field. Utilizing precision manipulation and group control, LMCMs demonstrate a remarkable 98% cleaning efficiency in 93 s and can be recovered under the control of the directional magnetic field. This eco-friendly and energy-efficient microrobot is expected to provide a viable strategy to tackle the threat of microplastics or promote industrial microplastic removal.

Controlled entropy in tetra-hybrid nono-fluid helmholtz electroosmotic with motile germs via complex peristaltic pumping

Motile microorganisms, such as bacteria, can be engineered to transport medications directly to certain organs, such as cancer, tumors, enhancing drug efficacy and minimizing systemic side effects. These microorganisms can also be programmed to target and eliminate harmful bacteria, offering a novel approach to infection control. In parallel, functionalized nanomaterials show significant promise for precise manipulation of biological fluids. This focused approach improves drug efficacy while reducing systemic negative effects. Also, motile bacteria can be engineered to target and remove dangerous bacteria, providing a fresh approach to infection control. Nanomaterials with various functions show prodigious potential for precise operation of biological fluids. Tetra-hybrid nano-particles exhibit special electrical, optical, and thermal properties. They are composed of gold, silver, alumina, and titania. The streaming flow phenomena that result from the interactions of these nanocomposites with non-Newtonian biofluids, such as blood, can be studied using computational modeling. Considerations are made for forces such as non-Newtonian rheology, localized laser irradiation, and magnetohydrodynamics. Complex cellular trapping patterns are captured by predictions for temperature, velocity, and nanoparticle concentration profiles. Biocompatible multimodal nano-assemblies under magnetic actuation and thermos-plasmonic effects are used to exhibit precision biofluid control. To optimize, engineering parameters are visually analyzed. The unique features of tetra-hybrid nanoparticles, paired with motile microorganisms and non-Newtonian biofluid dynamics, allow for more precise therapeutic techniques, such as targeted medication administration and hyperthermia cancer treatment. By visualizing key engineering parameters, these findings highlight the potential for improved therapeutic strategies, such as targeted drug delivery and hyperthermia-based cancer treatments, enabled by the integration of tetra-hybrid nanoparticles and motile microorganisms in complex biofluid environments.

Design and realization of an isomorphic master-slave robotic system for precise sub-micrometer manipulations in ophthalmic surgery

Design and realization of an isomorphic master-slave robotic system for precise sub-micrometer manipulations in ophthalmic surgery

Real-Time Adaptive Inline Acidification Enhances Continuous pH Control for Viral Inactivation.

Existing low pH viral inactivation methods for continuous downstream processing of biologics typically rely on predictive models to estimate the necessary pH adjustments. However, these methods are of limited use during the process development stage due to the dynamic nature of capture chromatography, where batch variations can alter the eluted protein titer. This study introduces an inline viral inactivation system (IVIS) that utilizes real-time adaptive control and inline sensor readings to precisely regulate the pH manipulation for inline acidification and continuous viral inactivation. The IVIS, which includes a coiled flow inversion reactor (CFIR), is integrated with a multicolumn capture chromatography system to demonstrate a fully continuous process from protein capture chromatography to inline pH manipulation. The system achieved precise inline pH manipulation within ±0.15 and a narrow residence time distribution of 13.5min with a relative width of 0.7. The introduction of real-time inline pH manipulation with the IVIS signifies a notable advancement in managing critical process parameters (CPPs) and ensuring consistent product quality across varied production environments for continuous downstream bioprocessing.

A multimodal rotational acoustic manipulation device for hydrophilic/hydrophobic floating and submerged particles

Rotational acoustic manipulation technology offers precise control of particle motion, making it advantageous for applications in microfluidics, biomedicine, materials research, and so on. Current advanced techniques that use acoustic waves to rotate particles include microstructure vibration, microbubble oscillation, and acoustic holography. Although these methods have achieved some success in rotational acoustic manipulation, they face challenges such as limited types of particles, complex device fabrication, and single-mode manipulation. To address these issues, this study proposes a novel rotational acoustic manipulation device based on traveling wave acoustic fields. The traveling wave acoustic field is achieved by planning the vibration modes of the vibrational source. In this study, a ring-shaped piezoelectric ceramic with four-quadrant dual polarization is designed to excite two orthogonal B11 bending vibration modes of the vibrator. By adjusting the phase difference of the excitation signals, these two B11 bending vibration modes can be coupled into either clockwise or counterclockwise traveling wave vibration modes, thereby establishing unidirectional rotating traveling waves in the water within the PDMS ring. The PDMS ring features an open structure, meeting the requirements for manipulating both floating and submerged particles. The performance of the proposed acoustic manipulation device is validated and analyzed through experiments with hollow glass particles, hollow polystyrene particles, and solid polystyrene particles. The results demonstrate that the proposed acoustic manipulation device can achieve precise fixed-point self-rotation and regional revolution manipulation of particles, regardless of their floating, submerged, hydrophilic, or hydrophobic properties. This indicates the high universality and robustness of the device, making it applicable for the manipulation of various types of particles. Overall, this study introduces a novel acoustic manipulation method for particle rotation, providing strong support for the development and application of acoustic manipulation devices in diverse fields.

Robust Control of Chat-PM: A Switched Singular System with Mode-dependent Bounded Nonlinearity

This paper is concerned with the robust control of the composite hybrid aerial-terrestrial precise manipulator (Chat-PM), a quadrotor-based robot with aerial/terrestrial movement and payload transportation capabilities. Given the distinct dynamics between aerial and terrestrial locomotion modes, Chat-PM is modeled as a type of switched singular system. A nonlinear term is contained in the system to model the coupling between translational and rotational movements of Chat-PM, which is proven to be norm-bounded and mode-dependent. Besides, the estimation error of the robotic arm's interaction force/torque is treated as the disturbance of the system. By means of the mixed H2/H∞ approach, numerically testable stability criterion are obtained, based on which the existence conditions for controllers with satisfactory transient and disturbance attenuation performance are provided. Compared to traditional studies assuming the nonlinearity term to be mode-independent, the conservatism in the controller design is reduced. Experimental results are provided to demonstrate the effectiveness of the proposed approach.