Finger Structure Research Articles

Angle-dependent ion-beam etching of RuAl thin films for structuring GHz-frequency electronics

The ruthenium aluminide (RuAl) alloy is a promising electrode material for wireless surface acoustic wave sensors working under harsh conditions at high temperatures. However, during the structuring of RuAl thin films using ion-beam etching, etched material can redeposit at the edges of the electrodes and form objects, so-called fences, on top of the structured features. These decrease the high-temperature stability and lead to an undesired alteration of the sensor performance. In this work, the angle-dependent ion-beam etching of RuAl thin films was investigated to inhibit the formation of such fence structures. The etch rate was determined as a function of the etching angle between ion-beam and sample surface in a range between 90° and 40°. Furthermore, finger structures with pitches below 500 nm, which are required for devices working in the intended GHz regime, were patterned to study the influence of the etching angle on the profile of the RuAl electrode fingers using transmission electron microscopy and energy-dispersive x-ray spectroscopy. The results show that an etching angle of 50° results in the highest etch rate. For etching angles of 50° and below, the width of the fences is reduced below 10 nm, so they break off during standard resist removal procedures. Such low etching angles lead to shadowed areas on the side of structured features in which unetched material remains. However, this material can be removed by using a two-step etching process combining a 50° step with a 90° step. This process is capable of structuring fence-free trapezoidal-shaped electrode finger profiles. Therefore, the developed process is well suited for the fabrication of high-temperature GHz-frequency RuAl electrodes.

Optimizing strategy of bifacial TOPCon solar cells with front-side local passivation contact realized by numerical simulation

The tunnelling oxide passivation contact (TOPCon) solar cells have been impressive in the global photovoltaic (PV) market originating from their high efficiency and stability. However, it exhibits significant recombination losses due to its boron diffusion, laser damage and metal-semiconductor contact on front side. The bifacial TOPCon structure demonstrates massive potential in the improvement of passivation and contact performance with the premise that it can solve the parasitic absorption of polycrystalline silicon (poly-Si). In this study, the localized poly finger structure with excellent optics and passivation performance is designed in the front side of bifacial solar cells to compare with traditional TOPCon and full-area poly passivation devices. The theoretical efficiency and detailed power loss analysis in our simulation reveal that suppressing the recombination of FSF (front surface field) and the contact area is the crucial strategy to improve device performance, with optimized efficiency of 26.62 % and FF of 85.16 %. These results indicate that the route of BJ (back junction) structure containing localized selective contact and full coverage high-quality passivation holds potential in realizing both high Jsc and Voc for FBC (front and back contact) solar cells, featuring great instructive significance for future industrialization of PV production.

Transcription factor Yin Yang 1 enhances epithelial-mesenchymal transition, migration, and stemness of non-small cell lung cancer cells by targeting sonic hedgehog.

Non-small cell lung cancer (NSCLC) is a frequent type of lung cancer. Transcription factor Yin Yang 1 (YY1), an endogenous transcription factor containing zinc finger structure, can accelerate NSCLC progression. However, the impact of YY1 on the stemness of NSCLC cells and the mechanism of promoting NSCLC cell progression is unclear. YY1 and Sonic hedgehog (Shh) expressions were monitored by RT-qPCR, western blot, and immunohistochemistry. Overall survival was tested through Kaplan-Meier analysis. The interaction between YY1 and Shh was confirmed. Then, cell migration, stemness, and epithelial-mesenchymal transition (EMT) were assessed with functional experiments in vitro and in vivo. YY1 and Shh were highly expressed in NSCLC tissues and positively correlated with the poor OS of NSCLC patients. Functional experiments denoted that YY1 or Shh overexpression could accelerate EMT, migration, and stemness of NSCLC cells, and YY1 or Shh knockdown played the opposite role to its overexpression. Mechanism analysis disclosed that Shh, as a target gene of YY1, was positively related to YY1. The rescued experiment manifested that Shh silencing could reverse the induction effect of YY1 overexpression on EMT, migration, and stemness of NSCLC cells. In vivo experiments also confirmed that YY1 could accelerate tumor growth and EMT and weaken apoptosis. YY1 promotes NSCLC EMT, migration, and stemness by Shh, which might be novel diagnostic markers and therapeutic targets for NSCLC therapy.

Fingertip Reconstruction in Hand Injuries

Fingertip amputations are a significant issue in the United States, with approximately 45,000 performed annually, with a 7.5 per 100,000 incidence rate. The primary cause of finger injuries is metal objects and bladed hand instruments, which can lead to cuts, loss of limbs, or damage to nerves and blood vessels. Therapy aims to restore sensation, long-lastingness, and bone support for nail development. Inadequate management can result in cosmetic issues, cold sensitivity, skin soreness, and persistent impairment in functionality. Nail bed injuries, such as lacerations, avulsions, and crush injuries, can result in post-traumatic fingertip amputation. Physical examinations are necessary to evaluate the functional and sensory capabilities of the damaged finger. Surgical intervention is necessary for severe cases, with primary closure or revision amputation being the preferred procedure. Full-thickness skin grafting is also used for fingertip amputations, preserving the structure of the recipient's fingers and addressing areas with insufficient skin. Flap repair is a method for managing fingertip amputations, using skin from another area or distant region. Local flaps are best for small covering areas, while regional flaps are used for extensive incisions. These flaps prevent prolonged immobilization and allow for a return of feeling in the fingertip. Post-amputation complications include delayed wound healing, nail abnormalities, heightened sensitivity, pain, intolerance to cold, scar retraction, limited finger movement, persistent ulcers, infection, and loss of tissue flaps. Inadequate management of fingertip amputations can lead to cosmetic flaws, reduced tolerance to cold, and increased skin sensitivity.

Enhancing compliant gripper performance: Exploiting electro-adhesion to increase lifting force over grasping force

On the landscape of solutions to deal with delicate objects, the development and use of soft grippers is a topic of increasing interest, with a large number of prototypes proposed by the research community employing non-linear soft materials and based on diverse actuation means. However, increasing compliance usually leads to the reduction of lifting capacity. As a recent promising approach, shear forces exerted by a soft gripper can be enhanced by exploiting the electro-adhesion (EA) effect. Following this research trend, this paper proposes a new gripper that combines a compliant finger structure, with geometry taken from the FESTO FinRay but made of a softer material (a urethane rubber), and custom EA pads that are placed on the fingers at the interface with the grasped object. Following hyper-elastic model identification of the considered material and preliminary functional verification of gripper design via finite element simulations, the gripper is then manufactured and tested by means of a specific setup, replicating the grasping and lifting of cylindrical objects with different diameters. The results clearly show that the new gripper makes it possible to generate holding forces similar to those of the FESTO FinRay, but with significantly lower pressures on the grasped object (77 % less). Besides enabling the handling of more fragile items, the drastic increase in gripper compliance also results in lower mechanical actuation force (namely, 71 % less of gripping energy) required to generate the same holding force, with a consequent reduction of operation costs and sustainability of its application.

Convective structures of salt fingers at a neutrally buoyant density interface

Convective structures of salt fingers at a neutrally buoyant density interface

A review of the genetic background in complicated WT1-related disorders.

The Wilms tumor 1 (WT1) gene was first identified in 1990 as a strong candidate for conferring a predisposition to Wilms tumor. The WT1 protein has four zinc finger structures (DNA binding domain) at the C-terminus, which bind to transcriptional regulatory sequences on DNA, and acts as a transcription factor. WT1 is expressed during kidney development and regulates differentiation, and is also expressed in glomerular epithelial cells after birth to maintain the structure of podocytes. WT1-related disorders are a group of conditions associated with an aberrant or absent copy of the WT1 gene. This group of conditions encompasses a wide phenotypic spectrum that includes Denys-Drash syndrome (DDS), Frasier syndrome (FS), Wilms-aniridia-genitourinary-mental retardation syndrome, and isolated manifestations of nephropathy or Wilms tumor. The genotype-phenotype correlation is becoming clearer: patients with missense variants in DNA binding sites including C2H2 sites manifest DDS and develop early-onset and rapidly developing end-stage kidney disease. A deeper understanding of the genotype-phenotype correlation has also been obtained in DDS, but no such correlation has been observed in FS. The incidence of Wilms tumor is higher in patients with DDS and exon-truncating variants than in those with non-truncating variants. Here, we briefly describe the genetic background of this highly complicated WT1-related disorders.

Design of Adaptive Grippers for Fruit-Picking Robots Considering Contact Behavior

Adaptability to unstructured objects and the avoidance of target damage are critical challenges for flexible grippers in fruit-picking robots. Most existing flexible grippers have many problems in terms of control complexity, stability and cost. This paper proposes a flexible finger design method that considers contact behavior. The new approach incorporates topological design of contact targets and introduces contact stress constraints to directly obtain a flexible finger structure with low contact stress and good adaptability. The study explores the effects of design parameters, including virtual spring stiffness, volume fraction, design domain size, and discretization, on the outcomes of the flexible finger topology optimization. Two flexible finger structures were selected for comparative analysis. The experimental results verified the effectiveness of the design method and the maximum contact stress was reduced by about 70%. An adaptive two-finger gripper was developed. This design allows the gripper to achieve damage-free grasping without additional sensors and control systems. The adaptive and contact performances of the grippers with different driving modes were analyzed. Practical grasping tests were also performed, including evaluation of adaptive performance, stability, and maximum grasping weight. The results indicate that gripper 2 with flexible finger 2 excelled in contact stress and adaptive wrapping, making it well-suited for grasping unstructured and fragile objects. This paper provides valuable insights for the design and application of flexible grippers for picking robots, offering a promising solution to enhance adaptability while minimizing target damage.

Design and Control of a Tendon-Driven Robotic Finger Based on Grasping Task Analysis.

To analyze the structural characteristics of a human hand, data collection gloves were worn for typical grasping tasks. The hand manipulation characteristics, finger end pressure, and finger joint bending angle were obtained via an experiment based on the Feix grasping spectrum. Twelve types of tendon rope transmission paths were designed under the N + 1 type tendon drive mode, and the motion performance of these 12 types of paths applied to tendon-driven fingers was evaluated based on the evaluation metric. The experiment shows that the designed tendon path (d) has a good control effect on the fluctuations of tendon tension (within 0.25 N), the tendon path (e) has the best control effect on the joint angle of the tendon-driven finger, and the tendon path (l) has the best effect on reducing the friction between the tendon and the pulley. The obtained tendon-driven finger motion performance model based on 12 types of tendon paths is a good reference value for subsequent tendon-driven finger structure design and control strategies.

A variable stiffness design method for soft robotic fingers based on grasping force compensation and linearization

Abstract Soft fingers play an increasingly important role in robotic grippers to achieve adaptive grasping with variable stiffness features. Previous studies of soft finger design have primarily focused on the optimization of the structural parameters of existing finger structures, but limited efforts have been put into the design methodology from fundamental grasping mechanisms to finger structures with desired grasping force features. To this aim, a fundamental architecture of soft fingers is proposed for analyzing common soft finger features and the influence of the internal structures on the overall grasping performance. In addition, three general performance metrics are introduced to evaluate the grasping performance of soft finger designs. Then, a novel method is proposed to combine the variable stiffness structure with the fundamental architecture to compensate for the grasping force of the finger and linearization. Subsequently, an embodiment design is proposed with a cantilever spring-based variable stiffness (CSVS) mechanism based on the method, and a multi-objective optimization method is employed to optimize the design. Besides, the CSVS features are analyzed through finite element analysis (FEA), and by comparing the grasping performance between the V-shape finger and the CSVS finger, it is demonstrated that the design method can effectively shorten the pre-grasp stage and linearize the grasping force in the post-grasp stage while reducing the likelihood of sliding friction between the finger and the grasped object. Finally, experiments are conducted to validate the accuracy of the FEA model, the effectiveness of the design methodology, and the adaptability of the CSVS finger.

Study on two-phase displacement law considering mass transfer and diffusion

The influence of channeling on viscous fingering instability of CO2 miscible displacement is studied in the paper. Due to the viscous fingering not easily observed in porous media, channeling is used to simplify the viscous fingering instability. We adopted nonlinear simulation to investigate the development of viscous fingering instability during the displacement of Newtonian fluids in a channel by miscible fluids, and the influence of different Pe and different viscosity ratio R was studied. Under homogeneous conditions, when R is the same, the larger the Pe is, the more obvious the convection in the process of CO2 displacement is, the earlier the viscous fingering occurs, and the shorter the time for the finger to break through to the right boundary is. When Pe is the same, the larger the R is, the more unstable the contact area of miscible displacement becomes. More finger structures appear, and more complex fingering phenomena occur. The larger the R is, the earlier the fingering phenomenon appears, and the earlier it breaks through to the right boundary. In addition, we studied the change in Relative Mixing Length (RML) during the diffusion process quantitatively. Finally, our investigation delved into the impact of heterogeneity on viscous fingering. We observed that under significant heterogeneity, viscous fingering tends to manifest preferentially in the direction of increasing permeability.

Identification of Dof transcription factors in Dendrobium huoshanense and expression pattern under abiotic stresses.

Introduction: DNA-binding with one finger (Dof) transcription factors (TFs) are a unique family of TFs found in higher plants that regulate plant responses to light, hormones, and abiotic stresses. The specific involvement of Dof genes in the response to environmental stresses remains unknown in D. huoshanense. Methods: A total of 22 Dof family genes were identified from the D. huoshanense genome. Results: Chromosome location analysis showed that DhDof genes were distributed on 12 chromosomes, with the largest number of Dof genes located on chromosome 8. The phylogenetic tree revealed that DhDofs could be categorized into 11 distinct subgroups. In addition to the common groups, DhDof4, DhDof5, DhDof17, and the AtDof1.4 ortholog were clustered into the B3 subgroup. Group E was a newly identified branch, among which DhDof6, DhDof7, DhDof8, and DhDof9 were in an independent branch. The conserved motifs and gene structure revealed the differences in motif number and composition of DhDofs. The dof domain near the N-terminus was highly conserved and contained a C2-C2-type zinc finger structure linked with four cysteines. Microsynteny and interspecies collinearity revealed gene duplication events and phylogenetic tree among DhDofs. Large-scale gene duplication had not occurred among the DhDofs genes and only in one pair of genes on chromosome 13. Synteny blocks were found more often between D. huoshanense and its relatives and less often between Oryza sativa and Arabidopsis thaliana. Selection pressure analysis indicated that DhDof genes were subject to purifying selection. Expression profiles and correlation analyses revealed that the Dof gene under hormone treatments showed several different expression patterns. DhDof20 and DhDof21 had the highest expression levels and were co-expressed under MeJA induction. The cis-acting element analysis revealed that each DhDof had several regulatory elements involved in plant growth as well as abiotic stresses. qRT-PCR analysis demonstrated that DhDof2 was the main ABA-responsive gene and DhDof7 was the main cold stress-related gene. IAA suppressed the expression of some Dof candidates, and SA inhibited most of the candidate genes. Discussion: Our results may provide new insights for the further investigation of the Dof genes and the screening of the core stress-resistance genes.

Experimental investigation on adaptive grasping of a novel 3D-MSSPA gripper in complex space

Many achievements for soft grippers are made in the structure design and grasping of target objects. However, there are limited studies on grasping objects with different attributes by soft grippers with omnidirectional bending capabilities within environments containing obstacles. In this paper, drawing inspiration from the multi-segment structure of the biological finger, a 3D-multi-segment soft pneumatic actuator (3D-MSSPA) with a strong envelope and omnidirectional independent bending is designed and manufactured. Additionally, we developed a novel prototype for a soft gripper prototype. A quasi-static model is proposed to effectively describe the bending deformation of 3D-MSSPA. The experimental results show that, for an applied pressure of 40kPa, the single segment SPA achieves a maximum bending angle of 175.2°, aligning closely with the theoretical prediction. Furthermore, the omnidirectional bending ability of multi-segments is analyzed through the finite element method, and a position compensation method for gravity deviation is presented. Through experiments, the pressure fore and lifting force of the soft gripper are investigated, yielding maximum values of 11N and 4.08N, respectively. These results serve as a benchmark for the mass grasping range of the target objects. Finally, the experiments are conducted to demonstrate the soft gripper’s adaptive and flexible grasping capabilities for objects with varying attributes, in both free space and complex space with obstacles. These experiments showcase their ability to avoid obstacles, adaptively grasp objects, and their good envelope ability. The proposed 3D-MSSPA can provide good inspiration and reference for flexible applications, particularly in fields such as post-disaster rescue and rehabilitation medicine.

Patterns, Transport, and Anisotropy of Salt Fingers in Shear

Abstract Through an expansive series of simulations, we investigate the effects of spatially uniform shear on the transport, structure, and dynamics of salt fingers. The simulations reveal that shear adversely affects the heat and salt fluxes of the system, reducing them by up to an order of magnitude. We characterize this in detail across a broad range of Richardson numbers and density ratios. We demonstrate that the density ratio is strongly related to the amount of shear required to disrupt fingers, with larger density ratio systems being more susceptible to disruption. An empirical relationship is proposed that captures this behavior that could be implemented into global ocean models. The results of these simulations accurately reproduce the microstructure measurements from North Atlantic Tracer Release Experiment (NATRE) observations. This work suggests that typical salt finger fluxes in the ocean will likely be a factor of 2–3 less than predicted by models not taking the effects of shear on double-diffusive systems into account. Significance Statement The purpose of this work is to measure how large-scale (>1 m) motion affects specific small-scale (∼1 cm) mixing in the ocean. We approach this topic using simulations of meter-scale boxes of fluid containing both temperature and salt concentration with an applied background flow. We measure how this background flow changes the mixing of temperature and salt as the strength of the applied flow increases. We find that current estimates may overpredict mixing at this scale throughout the World Ocean by about a factor of 2–3, on average. This could have consequences for estimates of climate in addition to heat, salt, nutrient, and pollutant transport.

Anatomically-Inspired Robotic Finger with SMA Tendon Actuation for Enhanced Biomimetic Functionality.

This research introduces an advanced robotic finger designed for future generalist robots, closely mimicking the natural structure of the human finger. The incorporation of rarely discussed anatomical structures, including tendon sheath, ligaments, and palmar plates, combined with the usage of anatomically proven 3D models of the finger, give rise to the highly accurate replication of human-like soft mechanical fingers. Benefiting from the accurate anatomy of muscle insertions with the utilization of Shape Memory Alloy (SMA) wires' muscle-like actuation properties, the bonding in-between the flexor tendons and extensor tendons allows for the realization of the central and lateral band of the finger anatomy. Evaluated using the computer vision method, the proposed robotic finger demonstrates a range of motion (ROM) equivalent to 113%, 87% and 88% of the human dynamic ROM for the DIP, PIP and MCP joints, respectively. The proposed finger possesses a soft nature when relaxed and becomes firm when activated, pioneering a new approach in biomimetic robot design and offering a unique contribution to the future of generalist humanoid robots.

A novel GATA3 frameshift mutation causes hypoparathyroidism, sensorineural deafness, and renal dysplasia syndrome

BackgroundHypoparathyroidism, sensorineural deafness, and renal dysplasia (HDR) syndrome (Barakat syndrome) is a rare autosomal dominant disorder caused by mutations in the gene encoding GATA3 on chromosome 10p14. MethodInformed consent was obtained from a 38-year-old female patient. 5 mL of venous blood was collected and sent for whole-exome sequencing. GATA3 constructs of both wild-type and mutant were transfected into HEK-293 T cells. Three-dimensional modeling, luciferase-reporter gene test, western blotting and cellular immunofluorescence were used to evaluate the effect of the mutation. ResultsA novel frameshift mutation c. 677dup(p.Pro227AlafsTer77), named P227Afs, was found in GATA3. Three-dimensional modeling revealed that the mutation caused the loss of the dual zinc finger structures 1 and 2 (ZNF1 and ZNF2) of the synthesized protein. Expression of wild-type GATA3 produced a six-fold increase in luciferase activity when compared with pcDNA3.1 vector only (P < 0.001), whereas the P227Afs mutant showed no increase. The mutation significantly reduced the transcriptional activity of GATA3. Immunofluorescence and western blotting analyses demonstrated that the mutation changed the nuclear location of GATA3 and caused difficulty in nuclearization. ConclusionA novel heterozygous frameshift mutation in GATA3 was identified and showed to result in difficult nuclearization, and a dominant-negative effect on the wild-type.

Classification Of Robots and Industrial and Medical Applications

In the last 100 years, robots have evolved from fantasy to reality. Their design, research, and manufacture require the combination of various subjects such as CS, EEE, ME, AI, and others. The main objective is to replace humans in performing heavy or impossible tasks. Robots are classified into different categories based on their era and usefulness. This thesis will analyze industrial robots in terms of their basic stress conditions and activity scope with four degrees of freedom for the normal robot arm. The system architecture, various field interactions, and structure of mechanical fingers for human-like robot arms will also be analyzed. Additionally, this paper will examine the usefulness of service industry robots and highlight the exoskeleton robot for medical treatment by analyzing the forces, torques, and displacements during the walking of patients with lower limb disabilities. The interaction force between humans and exoskeleton robots will be calculated and a model will be constructed. Finally, some difficulties and possible solutions will be presented.

TaWRKY31, a novel WRKY transcription factor in wheat, participates in regulation of plant drought stress tolerance

BackgroundWheat, a crucial food crop in China, is highly vulnerable to drought stress throughout its growth and development. WRKY transcription factors (TFs), being one of the largest families of TFs, play a vital role in responding to various abiotic stresses in plants.ResultsHere, we cloned and characterized the TF TaWRKY31 isolated from wheat. This TF, belonging to the WRKY II family, contains a WRKYGQK amino acid sequence and a C2H2-type zinc finger structure. TaWRKY31 exhibits tissue-specific expression and demonstrates responsiveness to abiotic stresses in wheat. TaWRKY31 protein is localized in the nucleus and can function as a TF with transcription activating activity at the N-terminus. Results showed that the wheat plants with silenced strains (BSMV:TaWRKY31-1as and BSMV:TaWRKY31-2as) exhibited poor growth status and low relative water content when subjected to drought treatment. Moreover, the levels of O2·−, H2O2, and malondialdehyde (MDA) in the BSMV:TaWRKY31-induced wheat plants increased, while the activities of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) decreased. Compared to control plants, BSMV:TaWRKY31-induced wheat plants exhibited lower expression levels of TaSOD (Fe), TaPOD, TaCAT, TaDREB1, TaP5CS, TaNCED1, TaSnRK2, TaPP2C, and TaPYL5.Under stress or drought treatment conditions, the overexpression of TaWRKY31 in Arabidopsis resulted in decreased levels of H2O2 and MDA, as well as reduced stomatal opening and water loss. Furthermore, an increase in resistance oxidase activity, germination rate, and root length in the TaWRKY31 transgenic Arabidopsis was observed. Lastly, overexpression of TaWRKY31 in Arabidopsis resulted in higher the expression levels of AtNCED3, AtABA2, AtSnRK2.2, AtABI1, AtABF3, AtP5CS1, AtSOD (Cu/Zn), AtPOD, AtCAT, AtRD29A, AtRD29B, and AtDREB2A than in control plants.ConclusionsOur findings indicate that TaWRKY31 enhances drought resistance in plants by promoting the scavenging of reactive oxygen species, reducing stomatal opening, and increasing the expression levels of stress-related genes.

Sugar-plastic assisted fabrication of hollow PDMS wearable fabrics toward excellent sensory capabilities

By imitating the hierarchical structure of fingers, this lightweight and breathable pressure sensor exhibits excellent pressure-sensing performance and tactile perception.

Hybrid-Driven Origami Gripper with Variable Stiffness and Finger Length.

Soft grippers due to their highly compliant material and self-adaptive structures attract more attention to safe and versatile grasping tasks compared to traditional rigid grippers. However, those flexible characteristics limit the strength and the manipulation capacity of soft grippers. In this paper, we introduce a hybrid-driven gripper design utilizing origami finger structures, to offer adjustable finger stiffness and variable grasping range. This gripper is actuated via pneumatic and cables, which allows the origami structure to be controlled precisely for contraction and extension, thus achieving different finger lengths and stiffness by adjusting the cable lengths and the input pressure. A kinematic model of the origami finger is further developed, enabling precise control of its bending angle for effective grasping of diverse objects and facilitating in-hand manipulation. Our proposed design method enriches the field of soft grippers, offering a simple yet effective approach to achieve safe, powerful, and highly adaptive grasping and in-hand manipulation capabilities.