Multidirectional Motion Research Articles

Wear Mechanism and Wear Debris Characterization of ULWPE in Multidirectional Motion

Wear Mechanism and Wear Debris Characterization of ULWPE in Multidirectional Motion

TSOM: Small object motion detection neural network inspired by avian visual circuit

Detecting small moving objects in complex backgrounds from an overhead perspective is a highly challenging task for machine vision systems. As an inspiration from nature, the avian visual system is capable of processing motion information in various complex aerial scenes, and the Retina-OT-Rt visual circuit of birds is highly sensitive to capturing the motion information of small objects from high altitudes. However, more needs to be done on small object motion detection algorithms based on the avian visual system. In this paper, we conducted mathematical description based on extensive studies of the biological mechanisms of the Retina-OT-Rt visual circuit. Based on this, we proposed a novel tectum small object motion detection neural network (TSOM). The TSOM neural network includes the retina, SGC dendritic, SGC Soma, and Rt layers, each corresponding to neurons in the visual pathway for precise topographic projection, spatial–temporal encoding, motion feature selection, and multi-directional motion integration. Extensive experiments on pigeon neurophysiological experiments and image sequence data showed that the TSOM is biologically interpretable and effective in extracting reliable small object motion features from complex high-altitude backgrounds.

Wafer-scale integration of two-dimensional perovskite oxides towards motion recognition

Two-dimensional semiconductors have shown great potential for the development of advanced intelligent optoelectronic systems. Among them, two-dimensional perovskite oxides with compelling optoelectronic performance have been thriving in high-performance photodetection. However, harsh synthesis and defect chemistry severely limit their overall performance and further large-scale heterogeneous integration. Here, we report the wafer-scale integration of highly oriented nanosheets by introducing a charge-assisted oriented assembly film-formation process and confirm its universality and scalability. The shallow-trap dominance induced by structural optimization endows the device with a distinguished performance balance, including high photosensitivity close to that of single nanosheet units and fast response speed. An integrated ultra-flexible 256-pixel device demonstrates the versatility of material-to-substrate integration and conformal imaging functionality. Moreover, the device achieves efficient recognition of multidirectional motion trajectories with an accuracy of over 99.8%. Our work provides prescient insights into the large-area fabrication and utilization of 2D perovskite oxides in advanced optoelectronics.

Proximal Humerus Reconstruction in Skeletally Immature Patients

Proximal humerus reconstruction after oncologic resection is complex, with numerous muscular attachments, proximity of critical neurovascular structures, and dynamic stability granting multidirectional motion at the glenohumeral articulation. In skeletally immature patients, additional factors increase the complexity, including remaining limb growth and humerus size. Limb length discrepancy affects the limb's esthetics and function while the humerus size can limit fixation strategies and intramedullary device use. Reconstruction options used in isolation or combination include endoprostheses, osteoarticular allografts, allograft-prosthetic composites, autografts, and arthrodesis. Unique limb salvage options to address the unique factors in young, skeletally immature patients include vascularized fibular epiphyseal transfer, claviculo pro humeri, and expandible endoprostheses. Each option has advantages and disadvantages for anticipated function, durability, shoulder stability, and complications. This review aims to aid preoperative planning and decision making for surgeons and patients undergoing proximal humerus resection and reconstruction with notable remaining growth potential.

Strong and anti-swelling nanofibrous hydrogel composites inspired by biological tissue for amphibious motion sensors.

Conductive hydrogel-based sensors are increasingly favored for flexible electronics due to their skin-like characteristics. However, conventional hydrogels suffer from significant swelling in humid environments and poor mechanical properties which largely restrict their applications in wearable electronic devices, especially for underwater sensing. Herein, drawing inspiration from the extracellular matrix (ECM) structure, a TPU-PVAc@AgNPs/MXene nanofibrous hydrogel composite (TPAMH) with excellent mechanical robustness and anti-swelling properties is developed. The TPAMH nanofibrous hydrogel composite is created by integrating the silver nanoparticles (AgNPs) and MXene nanosheets into an interwoven network comprising of stiff TPU nanofibers as the fibril scaffold and formic acid-crosslinked PVA hydrogel fibers as the elastic matrix (PVAc). Benefiting from the unique ECM structure, the obtained nanofibrous hydrogel composites exhibit exceptional tensile strength (4.47 MPa), remarkable elongation at break (621%), excellent anti-swelling properties, and high detection sensitivity (maximum gauge factor = 105.02), which are sufficient to monitor body motions in both air and water environments effectively. They can detect large strain movements of fingers, elbows, wrists, and knees, as well as small strain physiological signals such as frown, smile, and pulse beats, with high accuracy. Particularly noteworthy is their ability to accurately identify underwater multidirectional motions and facilitate underwater smart alarms using Morse code.

Extremely Stable, Multidirectional, All‐in‐One Piezoelectric Bending Sensor with Cycle up to Million Level

AbstractFlexible bending sensors are crucial components of flexible/wearable electronics. However, their broad application is restricted by their difficulty in sensing different bending directions and, more importantly, their significant output attenuation after long cycles. Herein, a new design of an All‐in‐One piezoelectric bending sensor is proposed, in which double‐deck, cross‐over 3D interdigital microelectrodes (silver nanowires (Ag NWs)) are embedded in a piezoelectric polymer film (poly(vinylidene fluoride‐trifluoroethylene (P(VDF‐TrFE))). The piezoelectric film with the embedded 3D microelectrodes exhibits a high anisotropy coefficient ( > 1) based on dual piezoelectric modes (d31 and d33), which renders it more sensitive to different bending directions. More importantly, the homogeneous interconnected interface and heterogeneous microinterlocked interface formed inside the sensor significantly enhance its interface mechanical properties, with at least a tensile strength of 51 MPa, a shear strength of 28 MPa, and an interfacial toughness of 300 J m−2, which are nearly two orders of magnitude greater than those of conventional sandwich architectures. The prepared All‐in‐One sensor shows an extremely stable piezoelectric output over as many as 16 00 000 bending cycles, which represents a remarkable breakthrough. Furthermore, a single sensor can be used to remotely control the multidirectional motion of a smart car, demonstrating enormous potential in practical applications.

Wheel Drive Driverless Vehicle Handling and Stability Control Based on Multi-Directional Motion Coupling

Wheel Drive Driverless Vehicle Handling and Stability Control Based on Multi-Directional Motion Coupling

The passive biomechanics of the thumb carpometacarpal joint: An in vitro study

The thumb carpometacarpal (CMC) joint facilitates multidirectional motion of the thumb and affords prehensile power and precision. Traditional methods of quantifying thumb CMC kinematics have been largely limited to range-of-motion (ROM) measurements in 4 orthogonal primary directions (flexion, extension, abduction, adduction) due to difficulties in capturing multidirectional thumb motion. However, important functional motions (e.g., opposition) consist of combinations of these primary directions, as well as coupled rotations (internal and external rotation) and translations. Our goal was to present a method of quantifying the multidirectional in vitro biomechanics of the thumb CMC joint in 6 degrees-of-freedom. A robotic musculoskeletal simulation system was used to manipulate CMC joints of 10 healthy specimens according to specimen-specific joint coordinate systems calculated from computed tomography bone models. To determine ROM and stiffness (K), the first metacarpal (MC1) was rotated with respect to the trapezium (TPM) to a terminal torque of 1 Nm in the four primary directions and in 20 combinations of these primary directions. ROM and K were also determined in internal and external rotation. We found multidirectional ROM was greatest and K least in directions oblique to the primary directions. We also found external rotation coupling with adduction-flexion and abduction-extension and internal rotation coupling with abduction-flexion and adduction-extension. Additionally, the translation of the proximal MC1 was predominantly radial during adduction and predominantly ulnar during abduction. The findings of this study aid in understanding thumb CMC joint mechanics and contextualize pathological changes for future treatment improvement.

A multi-directional magnetic-driven multifunctional soft crawling robot

Multifunctional and multi-freedom integrated magnetic-driven soft robots have received widespread attention in the past decade. However, the current magnetic-driven soft crawling robots with multiple functional modules focus on the development of new materials or innovation of driving component. Herein, we propose a soft crawling robot that materializes multi-directional motion driven only through a unidirectional magnetic field (MF) while possessing the ability to communication, loading, and positioning. The locomotion of robot relies on ingenious leg design to generate differences in friction between each leg and the ground by controlling the MF intensity. The integrated wireless communication modules on the robot's legs serve as a medium for interacting with the external world, enabling the robot to effectively perceive the environment via electromagnetic coupling. In addition, the magnetic-driven soft crawling robot carries loads (3.37 g) larger than twice its own weight for motion. Overall, this work showcases a new paradigm for robot applications, providing a practicable idea for developing miniaturization, multi-directional soft crawling robots.

Light-Responsive Hydrogel Microcrawlers, Powered and Steered with Spatially Homogeneous Illumination.

Sub-millimeter untethered locomoting robots hold promise to radically change multiple areas of human activity such as microfabrication/assembly or health care. To overcome the associated hurdles of such a degree of robot miniaturization, radically new approaches are being adopted, often relying on soft actuating polymeric materials. Here, we present light-driven, crawling microrobots that locomote by a single degree of freedom actuation of their light-responsive tail section. The direction of locomotion is dictated by the robot body design and independent of the spatial modulation of the light stimuli, allowing simultaneous multidirectional motion of multiple robots. Moreover, we present a method for steering such robots by reversibly deforming their front section, using ultraviolet (UV) light as a trigger. The deformation dictates the robot locomotion, performing right- or left-hand turning when the UV is turned on or off respectively. The robots' motion and navigation are not coupled to the position of the light sources, which enables simultaneous locomotion of multiple robots, steering of robots and brings about flexibility with the methods to deliver the light to the place of robot operation.

The effects of postoperative malrotation alignment on outcomes of Gartland type III/IV paediatric supracondylar humeral fractures treated by close reduction and percutaneous K-wire fixation

PurposeIn this study, we aimed to investigate the effects of postoperative malrotation alignment on the outcomes of Gartland type III/IV paediatric supracondylar humeral fracture (SCHF) treated by close reduction and percutaneous K-wire fixation.MethodsBetween January 2014 and December 2021, 295 Gartland type III/IV paediatric SCHFs treated by close reduction and percutaneous K-wire fixation were selected for this retrospective study. The demographic, clinical and radiographic parameters of all cases were collected. The lateral rotation percentage (LRP) was measured on X-rays to evaluate postoperative malrotation alignment of the fracture. All cases were categorized into 4 groups according to LRP: LRP ≤ 10% (210, 71.2%), 10% < LRP ≤ 20% (41, 13.9%), 20% < LRP ≤ 30% (26, 8.8%) and LRP > 30% (18, 6.1%). The carrying angle, ranges of multidirectional motions, Mayo Elbow Performance Score (MEPS) and Flynn’s Standard Score (FSS) of the injured elbow were assessed 6 months postoperation and compared among different groups. ROC analysis based on LRP and the excellent/good rate of FSS was performed to determine the acceptable maximum degree of postoperative malrotation alignment.ResultsThere was no difference in the demographic characteristics (age, sex, injured side and fracture type), postoperative Baumann angle, carrying angle or range of forearm rotation among the 4 groups (P > 0.05). The operation time and time from operation to K-wire removal were longer in the 20% < LRP ≤ 30% and LRP > 30% groups than in the LRP < 10% and 10% < LRP ≤ 20% groups (P < 0.001). The shaft condylar angle, range of elbow flexion, MEPS and FSS of the injured elbow 6 months postoperatively were lower in the 20% < LRP ≤ 30% and LRP > 30% groups than in the LRP < 10% and 10% < LRP ≤ 20% groups (P < 0.001). ROC analysis based on LRP and the excellent/good rate of FSS showed an area under the curve of 0.959 (95% CI 0.936–0.983), with a cutoff value of 26.5%, sensitivity of 95.3% and specificity of 90.1%.ConclusionA certain degree of residual malrotation alignment deformity of the SCHF may reduce the shaft condylar angle and extend the time from operation to removing the K-wire and affect elbow function, especially the range of elbow flexion. The acceptable maximum degree of residual malrotation deformity expressed as the LRP value was 26.5%.

Cartilage‐Inspired Multidirectional Strain Sensor with High Elasticity and Anisotropy Based on Segmented Embedded Strategy

AbstractFlexible, stretchable, and sensitive multidirectional sensing systems that can decouple different mechanical inputs and identify multidirectional signals are crucial for dynamic human signal perception and intelligent human–computer interaction. Most reported multidirectional sensors are suitable for discriminating in‐plane deformation directions, and the sensing materials are difficult to balance between stretchability and mechanical strength. Here, a segmented embedded structure strategy inspired by the interlaced structure of cartilage is proposed. This strategy combines soft and hard materials in a topological and zipper‐shear chain manner and balances the performance of reinforced composites with flexibility and high toughness. In the case of segmented embedded hydrogels (SEHs), a wearable multidirectional sensing system that can decouple and identify planar strain/pressure is constructed. The multidirectional sensing system exploits the inherent anisotropy and layered structure design of composites to decouple the sensing functions. Supported by machine learning algorithms, the high accuracy demonstration of the multidirectional sensors in typical multidirectional motion joint posture monitoring and recognition confirms their potential in practical applications such as personal health sensing and human–computer interaction.

Kinematic and optimal design of a three-wheeled holonomic omnidirectional robot platform for mobile manipulation tasks

Mobile manipulator robots are increasingly vital in industrial and service sectors, serving roles in assembly, inspection, and hazardous environments. The integration of a manipulator with a mobile robot base imposes unique demands on the vehicle's drive system. This paper introduces a three-wheel holonomic omnidirectional robot designed for mobile applications. It explores kinematic equations, electronic integration, and mechanical design for holonomic motion. This platform excels in mobility, capable of simultaneous translation and rotation, facilitating precise multidirectional motion. Its equilateral truncated triangular structure ensures stability, supporting up to 4 kg. With three omnidirectional wheels and DC motors, controlled by EMS 30A H-Bridge and Arduino Mega 2560, it offers an open platform for research and development. This robust platform aligns kinematic calculations with mathematical models, promising efficiency for diverse mobile manipulation robot applications.

A piezoelectric cantilever-asymmetric-conical-pendulum-based energy harvesting under multi-directional excitation

This paper introduces a novel approach to address the challenges faced by traditional unidirectional cantilever-based energy harvesters in adapting to multi-directional vibration environments. The proposed solution combines a flexible cantilever with an asymmetric-conical-pendulum structure which consists of two different concentrated end masses and a rigid thin rod By investigation of energy interchange relationship between the kinetic feature of the asymmetric pendulum and beam bending vibration under horizontal and vertical excitations respectively from base movements, utilizing the Lagrange's theorem and multiple-scale method, 1:2 internal resonance can be induced for enabling the delivery of multi-directional motion of pendulums to the unidirectional bending of cantilever. On this basis, the advantages of the proposed system are revealed by comparing with traditional piezoelectric cantilever and piezoelectric cantilever-single-pendulum systems. Furthermore, the performance of the voltage amplitude and operational bandwidth was potentially improved up to 128.5 % and 229.8 % under x-direction. In addition, it is confirmed that its maximum voltage RMS value is 57.9 % and 11.4 % higher than that of the piezoelectric cantilever-single-pendulum in the x- and z-directions, owing to its multi-peak energy harvesting over variable excitation amplitudes. Therefore, the feasibility and superiorities of the proposed configuration are demonstrated theoretically and numerically in this paper.

A Novel Wrench–Current Decoupling Strategy to Extend the Use of Small Lookup Data for a Long-Range Maglev Planar Motor

The maglev planar motor is one of the most promising industrial applications. The planar motor can increase flexibility in modern manufacturing with the multidirectional motion of the mover. In levitation control, the decoupling matrix is used to decouple the strong cross-coupling effect. The Lorentz force-based wrench matrices can be precomputed and stored in the lookup table. However, the motion range is restricted by the data range. This paper presents a wrench–current decoupling strategy to extend the use of small lookup data for long-range planar motion. The horizontal data range is 40 mm by 40 mm, which is determined from the minimally repetitive area of the planar coil array. The quadrant symmetry transformation is used to estimate the data for other areas. The experiment results demonstrated the accomplishment of the developed technique for long-range motion with a maximum motion stroke of 380 mm. The disc-magnet movers can levitate with a large air gap of 30 mm and have a total roll and pitch rotation range of 20 degrees.

Adding Tibial Tuberosity Medialization to Medial Patellofemoral Ligament Reconstruction Reduces Lateral Patellar Maltracking During Multidirectional Motion in a Computational Simulation Model

To determine whether adding tibial tuberosity medialization to medial patellofemoral ligament (MPFL) reconstruction reduces lateral patellar maltracking during a dynamic multidirectional activity and to investigate when medial patellofemoral contact pressures are elevated during daily activities, such as squatting. Seven computational models representing knees with patellar instability, including lateral patellar maltracking, were evaluated following simulated MPFL reconstruction (bisect offset index > .75). Tibial tuberosity medialization was added to MPFL reconstruction for each model. Patellar tracking during multidirectional motion was evaluated by simulating pivot landing. Analysis of pivoting focused on early flexion (5° to 40°). Patellofemoral contact pressures during daily function were evaluated by simulating knee squatting. Data were analyzed with paired comparisons between MPFL reconstruction with and without tuberosity medialization. The patella dislocated during pivoting for 2 models with an isolated MPFL reconstruction and for 1 model including tibial tuberosity medialization. Adding tibial tuberosity medialization to MPFL reconstruction significantly decreased bisect offset index by ∼0.1 from 5° to 40° (P < .03). For knee squatting, medializing the tibial tuberosity significantly increased maximum medial contract pressure by ∼0.5 MPa from 30° to 85° (P < .05) but did not significantly influence maximum lateral pressure. In this study of simulated multidirectional motion, MPFL reconstruction did not sufficiently constrain the patella for some knees. Adding tibial tuberosity medialization to MPFL reconstruction in these models reduced lateral patellar maltracking during multidirectional motion but increased pressure applied to medial cartilage during squatting. After establishing the influence of tibial tuberosity medialization on patellar maltracking for an idealized population, as was done in the current study, future simulation studies can be performed to better determine the anatomical characteristics of patients for whom tibial tuberosity medialization is needed to reduce the risk of postoperative patellar maltracking.

Prediction of safe zone for firefighters exposed to purely radiant heat source-a numerical analysis

This study delineates the heat transfer through multilayer fire retardant fabrics exposed to different levels of a purely radiant heat source with an air gap between fabric and skin. This numerical model critically focuses on different distances (longitudinal, transverse, and angular) of the firefighters from the heat source. This investigation considers the effect of dynamic change of longitudinal, transverse, and angular distance from the heat source through the motion of the firefighters and also considers the reflectivity of the outer layer of the multilayer fabric to predict the safe time and distance of the firefighters from the radiant heat source to avoid serious thermal damage. Finally, the study explains the effect of reflectivity of the fabric, multi directional motion of the firefighters, and different levels of radiant heat fluxes to assess the safe zone for the firemen to restrict their motion in order to obliterate the second and third degree thermal injury.

Multidirectional motion control of microparticles by a focused vortex laser beam in air

We propose a novel method for controlling a single microparticle moving arbitrary direction motions in air by a single focused vortex optical tweezer (OT). In principle, the movement of microparticles can be controlled synchronously by modulating the movement direction and movement path of the focused vortex laser beam. The spatial light modulator (SLM) modulates the 532 nm wavelength continuous-wave (CW) laser to create a Gaussian vortex laser beam for capturing and manipulating a microparticle in air. We demonstrate that a about 1 µm diameter carbon particle can be successfully controlled in a linear reciprocating or circular motion by a single focused vortex laser beam. In the experiment, the microparticles can be moved at a uniform speed of 0.167 cm per second by the designed route. By establishing a theoretical interference framework and numerical calculations, we have also demonstrated the effectiveness of this novel approach. This approach to controlling a single microparticle is of significant value for studying the control of multi-microparticles and 3D display in air.

Ultra-sensitive, Multi-directional Flexible Strain Sensors Based on an MXene Film with Periodic Wrinkles

The fast-growing motion capturing/monitoring technique has raised a great demand for flexible strain sensors. For capturing complex motions (e.g., facial motion), both the strain amplitude and direction should be accurately detected. Although some reported sensors based on anisotropic conductive networks are proved to show accurate localization of strain directions, it is still a great challenge to achieve both high sensitivity and a high sensing range in these designs. Here, a self-assembled Ti3C2Tx MXene film with parallel and periodic wrinkles is fabricated on a stretchable poly(dimethylsiloxane) substrate for constructing multi-directional strain sensors. During stretching, relative slip and crack will occur between the stacked MXene nanosheets, which contribute to high structural sensitivity in the MXene film. Meanwhile, the wrinkled structure contributes to high stretchability. As a result, the sensor based on the film with one-dimensional periodic wrinkles shows a large sensing range (>50%) and a gauge factor of 45. Furthermore, the sensor can accurately detect both the strain amplitude and direction by using the MXene film with two-dimensional wrinkles. It shows distinguishable electrical responses when detecting different-amplitude human/robot motions such as joint bending and walking. Additionally, the directions in complex human motions (e.g., facial motion) can also be well-tracked. This work provides an effective strategy to detect multi-directional motions.

3D printing deep-trap hierarchical architecture-based non-contact sensor for multi-direction motion monitoring

Non-contact sensors, intelligent electronics that interact with surrounding information with no physical contact, are highly desirable for human-machine interaction. Due to the increased sensing distance and expanded operation scope, it is anticipated the non-contact device exhibiting enhanced electrical output and detection range. Here, freeze-drying assisted 3D printing approach is employed to fabricate cellulose nanofiber (CNF)/MXene-based deep-trap hierarchical architecture for non-contact triboelectric nanogenerators, which exhibit excellent sensing performance for multi-direction motion monitoring. The intermolecular hydrogen bonding between CNF and MXene nanosheets facilitates the formation of a well-dispersed ink with suitable viscoelasticity for 3D printing. The incorporation of MXene nanosheets provides the printed scaffold with more open pores for increased charge generation. Meanwhile, the high electron trapping capability of MXene leads to a weakened electron escaping tendency and an increased decay time, which are beneficial for the device’s non-contact voltage output. Based on the as-prepared non-contact sensor, an all-printed sensing array and a 3D sensor are demonstrated for multi-site and multi-dimension motion trajectories monitoring, indicating its great potential in healthcare, safe navigation, and artificial intelligence.