Mechanical Failure Research Articles

A Review of Multiscale Mechanical Failures in Lithium-Ion Batteries: Implications for Performance, Lifetime and Safety

A Review of Multiscale Mechanical Failures in Lithium-Ion Batteries: Implications for Performance, Lifetime and Safety

Study on accuracy of prosthesis size selection for Naton robot-assisted medial unicondylar knee arthroplasty

To analyze the accuracy of prosthesis size selection in Naton robot-assisted medial unicondyle knee arthroplasty by comparing the actual prosthesis size used during operation and the preoperative planning. The clinical data of 100 patients (110 knees) who underwent Naton robot-assisted medial unicondylar knee arthroplasty between June 2023 and July 2024 was retrospectively analyzed, including 47 knees on left side and 63 knees on right side. There were 37 males (40 knees) and 63 females (70 knees) with a mean age of 65.4 years (range, 59-71 years). Body mass index was 22.2-28.6 kg/m 2 (mean, 25.4 kg/m 2). The disease duration ranged from 1 to 8 years (mean, 3.4 years). Preoperative planning was performed by Naton robotic surgical system based on lower limb CT data. The final prosthesis size after osteotomy was recorded and compared with the preoperative plan to analyse whether it was consistent with the preoperative plan, as well as the situation of knee flexion and extension gaps (<0.5 mm, >2.0 mm) corresponding to the different models of prostheses. During operation, 5 patients (5 knees) were treated with traditional UKA due to mechanical arm failure, software obstacles, significant bone amputation bias, or loose reference frame, and were excluded from the final analysis. The remaining 95 patients (105 knees) successfully received Naton robot-assisted surgery, and no related complications occurred. The prosthesis size was consistent with the preoperative plan in 101 knees (96.2%) on the femur side, 100 knees (95.2%) on the tibia side, and 97 knees (92.4%) on both femur and tibia sides. The prosthesis size was inconsistent in 3 cases (2.86%) on the femur side alone, 4 cases (3.81%) on the tibial side alone, and 1 case (0.95%) on both femur and tibial sides. Among the prostheses with different models, the flexion and extension gaps were less than 0.5 mm in 3 knees, the flexion gap was less than 0.5 mm and the extension gap was more than 2.0 mm in 3 knees, and the flexion gap was more than 2.0 mm and the extension gap was less than 0.5 mm in 2 knees. The accuracy of prosthesis size selection for Naton robot-assisted medial unicondylar knee arthroplasty is relatively high.

A Novel UBM/SIS Composite Biological Scaffold for 2-Year Abdominal Defect Repairing and Strength Recovery in Canine Model.

Biological scaffolds are widely utilized in hernia treatment due to their exceptional pro-regenerative properties, which mitigate scar formation. However, serious complications occurred, caused by inflammatory response, premature degradation, and mechanical failure. Consequently, improvements of the biological scaffold are necessary to mitigate these risks. In this study, a novel biological scaffold integrating basement membrane-containing urinary bladder matrix (UBM) and small intestinal submucosa (SIS) is developed, and its safety and effectiveness are assessed in comparison to a commercial SIS (c-SIS) scaffold. The introduction of UBM as top surface layers significantly promotes cell adhesion, facilitating rapid formation of isolated regeneration zone. Proteomic analysis has demonstrated a more efficientdecellularization of the UBM/SIS scaffold, which subsequently mitigates inflammation in murine models, and promotes the polarization of macrophages toward the pro-healing M2 phenotype in a rat model of abdominal wall muscle defect. Furthermore, a two-year repair trial is conducted on a full-thickness abdominal wall muscle defect in canine model and confirmed that the UBM/SIS scaffold exhibits reduced seroma occurrences and enhanced tissue repair performances. Overall, the efficacyof this novel biological scaffold suggests its potential to minimize hernia recurrence in clinical practice and mitigatepatient suffering from severe inflammatory responses.

EGS SO07 - Laparoscopic retrieval of endoscopic lithotripsy basket aided by laser fragmentation: Case presentation and literature review

Abstract Background Large or impacted common bile duct (CBD) stones that cannot be removed by conventional endoscopic methods sometimes require endoscopic mechanical lithotripsy. A rare but feared technical complication related to this is basket entrapment, where the stone-basket complex cannot be separated from each other due to mechanical failure and becomes impacted within the CBD. We present a novel case of laparoscopic CBD exploration and antegrade laser fragmentation of impacted stone-basket complex, and perform a literature review pertaining to this topic. Method This is a case report from a single district general hospital with laparoscopic capabilities but no access to Spyglass. The operation began with fundus first subtotal cholecystectomy and the cystic duct was ligated with PDS endoloops. A choledochotomy was made and dilated to allow insertion of a 7.5 Fr cholangioscope. Through this, laser lithotripsy was undertaken which reduced the stone size and permitted disengagement of the stone from basket. The stone was retrieved via enlargement of the choledochotomy, while the basket and wire retrieved orally. We subsequently performed a literature review of Pubmed, Google Scholar, and Embase. Results Laparoscopic retrieval of an impacted basket was first described in 1993, with the basket found lodged in the gallbladder. The technique involved a large cholecystotomy, followed by removal of the basket, closure of the gallbladder, and then cholecystectomy. Our literature review yielded 5 case reports of laparoscopic retrieval of basket from the CBD. Three authors describe manual disengagement of the basket by laparoscopic manipulation of the wires, one describes capturing an impacted Dormia basket with a second Dormia basket, and one describes direct mechanical fragmentation and subsequent balloon trawl of the remaining debris. Conclusion To our knowledge, this is the first case report describing laparoscopic CBD exploration with concurrent laser fragmentation to facilitate retrieval of impacted stone-basket complex following mechanical lithotripsy failure. We propose that this is a viable option in centres without Spyglass or electrohydraulic lithotripsy, but where expertise for emergency laparoscopic CBD exploration exists.

An Analysis of the Food and Drug Administration Manufacturer and User Facility Device Experience Database for MAGnetic Expansion Control Spinal Rods.

MAGnetic Expansion Control (MAGEC) rods can prevent repeated lengthening operations for scoliosis patients. However, there have been several Field Safety Notices issued, including a worldwide product recall due to actuator endcap separation. We aimed to review adverse events reported to the Food and Drug Administration (FDA) regarding MAGEC rods, focusing on MAGEC X. Reports submitted to the Manufacturer and User Facility Device Experience database in relation to MAGEC devices were accessed and analysed using R Statistical Software. Exclusion criteria included duplicate and literature review reports (n = 54). Free-text data were analysed using inductive content analysis. 1016 adverse events were reported to 11/30/2023. 99.0% (1006) were submitted by the manufacturer. Reports primarily arose from the UK (465, 45.8%) or US (421, 41.4%). From free-text data the most frequent adverse events were distraction mechanism failure (573), device wear (272), and actuator seal damage (180). Rod fracture (n = 48) was not significantly associated with rod diameter (≤ 5.0mm or > 5.0mm), p = 0.736. 234 reports referenced MAGEC X devices; actuator endcap separation was identified in 41.9% (99). Other events include failure of distraction (63), surface damage (31), and rod fracture (15). On 06/30/2020 MAGEC X2 received FDA approval. Twenty reports reference devices manufactured after this date, seven describe distraction mechanism failure; notably there are no reports of endcap separation. These data represent the largest series of adverse events reported for MAGEC rods, including significant new data regarding MAGEC X. As well as endcap separation, failure of distraction, surface damage, and rod fracture were reported.

Milling Machine Fault Diagnosis Using Acoustic Emission and Hybrid Deep Learning with Feature Optimization

This paper presents a fault diagnosis technique for milling machines based on acoustic emission (AE) signals and a hybrid deep learning model optimized with a genetic algorithm. Mechanical failures in milling machines, particularly in critical components like cutting tools, gears, and bearings, account for a significant portion of operational breakdowns, leading to unplanned downtime and financial losses. To address this issue, the proposed method first acquires AE signals from the milling machine. AE signals, capturing the dynamic responses of machine components, are transformed into continuous wavelet transform (CWT) scalograms for further analysis. Gaussian filtering is applied to enhance the clarity of these scalograms, effectively reducing noise while maintaining essential features. A convolutional neural network (CNN) based on the VGG16 architecture is utilized for spatial feature extraction, followed by a bidirectional long short-term memory (BiLSTM) network to capture the temporal dependencies of the scalograms. The genetic algorithm (GA) is used to optimize feature selection and ensure the selection of the most relevant features to further improve the model’s performance. The optimized features are finally fed into a fully connected (FC) layer of the proposed hybrid model for fault classification. The proposed method achieves an accuracy of 99.6%, significantly outperforming traditional approaches. This method offers a highly accurate and efficient solution for fault detection in milling machines, allowing for more reliable predictive maintenance and operational efficiency in industrial settings.

Clinical outcomes after extra-articular resection of hip joint tumour using a custom-made osteotomy guide and 3D-printed endoprosthesis with posterior column preserved.

For rare cases when a tumour infiltrates into the hip joint, extra-articular resection is required to obtain a safe margin. Endoprosthetic reconstruction following tumour resection can effectively ensure local control and improve postoperative function. However, maximizing bone preservation without compromising surgical margin remains a challenge for surgeons due to the complexity of the procedure. The purpose of the current study was to report clinical outcomes of patients who underwent extra-articular resection of the hip joint using a custom-made osteotomy guide and 3D-printed endoprosthesis. We reviewed 15 patients over a five-year period (January 2017 to December 2022) who had undergone extra-articular resection of the hip joint due to malignant tumour using a custom-made osteotomy guide and 3D-printed endoprosthesis. Each of the 15 patients had a single lesion, with six originating from the acetabulum side and nine from the proximal femur. All patients had their posterior column preserved according to the surgical plan. Postoperative pathological assessment revealed a negative surgical margin was achieved in all patients. At final follow-up, 13.3% (2/15) died and no recurrence occurred. The overall survival was 81.7% at five years. None of the patients showed any signs of aseptic loosening, and no wound healing issues were observed. In total, 20% (3/15) developed complications, with two cases of early hip dislocation and one case of deep infection. The cumulative incidence of mechanical and non-mechanical failure in this series was 13.7% and 9.3%, respectively, at five years. In this cohort, the mean time to full weightbearing was 5.89 (SD 0.92) weeks and the mean Musculoskeletal Tumor Society score was 24.1 (SD 4.4). For patients with a hip joint tumour who met the inclusion criteria and were deemed suitable for posterior column preservation, a custom-made osteotomy guide combined with 3D-printed endoprosthesis is worth performing when treating patients who require extra-articular resection of the hip joint, as it can achieve adequate margin for local control, maximize bone preservation to maintain pelvic ring integrity, reduce the risk of complications by simplifying the surgical procedure, and allow for more precise reconstruction for better function.

Effect of Manufacturing Method and Post-Processing Heat Treatment on Compressive Mechanical Properties, Failure Mechanism, and Microstructure of AlSi10Mg Strut-Based Lattice Structures

Effect of Manufacturing Method and Post-Processing Heat Treatment on Compressive Mechanical Properties, Failure Mechanism, and Microstructure of AlSi10Mg Strut-Based Lattice Structures

Inclusion of Muscle Forces Affects Finite Element Prediction of Compression Screw Pullout but Not Fatigue Failure in a Custom Pelvic Implant

Custom implants used for pelvic reconstruction in pelvic sarcoma surgery face a high complication rate due to mechanical failures of fixation screws. Consequently, patient-specific finite element (FE) models have been employed to analyze custom pelvic implant durability. However, muscle forces have often been omitted from FE studies of the post-operative pelvis with a custom implant, despite the lack of evidence that this omission has minimal impact on predicted bone, implant, and fixation screw stress distributions. This study investigated the influence of muscle forces on FE predictions of fixation screw pullout and fatigue failure in a custom pelvic implant. Specifically, FE analyses were conducted using a patient-specific FE model loaded with seven sets of personalized muscle and hip joint contact force loading conditions estimated using a personalized neuromusculoskeletal (NMS) model. Predictions of fixation screw pullout and fatigue failure—quantified by simulated screw axial forces and von Mises stresses, respectively—were compared between analyses with and without personalized muscle forces. The study found that muscle forces had a considerable influence on predicted screw pullout but not fatigue failure. However, it remains unclear whether including or excluding muscle forces would yield more conservative predictions of screw failures. Furthermore, while the effect of muscle forces on predicted screw failures was location-dependent for cortical screws, no clear location dependency was observed for cancellous screws. These findings support the combined use of patient-specific FE and NMS models, including loading from muscle forces, when predicting screw pullout but not fatigue failure in custom pelvic implants.

Treatment of adult spine deformity: A retrospective comparison of bone morphogenic protein and bone marrow aspirate with bone allograft.

This was a retrospective cohort study. ASD patients were stratified by use of intra-operative BMP (BMP +) or not (BMA + I) and surveyed for the development of complications and mechanical failure. Quality of life gained following the procedure was evaluated using quality-adjusted life years (QALYs). Cost was calculated using the PearlDiver database and CMS definitions. Multivariable analyses (ANCOVA) and logistic regression were used to adjust for confounding. 512 patients were included (60% BMP +). At baseline, BMP + patients were older (62.5 vs 60.8years, p < 0.010). Radiographic and quality-of-life metrics did not differ at follow up timepoints (all p > 0.05). BMP use was associated with higher supplemental rod use (OR: 7.0, 1.9 - 26.2, p = 0.004), greater number of levels fused (OR: 1.1, 1.03 - 1.17, p = 0.003) and greater neurological complications (OR: 5.0, 1.3 - 18.7, p = 0.017). Controlling for rod use and levels fused, BMP use was not associated with a lower risk of mechanical complications (OR 0.3, 95% CI: 0.2 - 3.0, p = 0.353), rod breakage (OR: 3.3, 0.6 - 18.7, p = 0.182) or implant failure (OR: 0.3, 0.04 - 1.51). At 2years, the BMP + cohort exhibited higher overall costs ($108,062 vs $95,144, p = 0.002), comparable QALYs (0.163 vs 0.171, p = 0.65) and higher cost per QALY (p = 0.001) at two years. In this analysis, BMP-2 application was not associated with superior outcomes when compared to a less costly biologic alternative (bone marrow aspirate + cancellous bone chips + i-Factor) following ASD surgery. The use of BMP-2 in ASD surgery appears to have reduced cost-efficacy at two years postoperatively.

Clinical Performance of 3D Printed Resin Composite Posterior Fixed Dental Prosthesis: A Permanent Solution?

This clinical trial aimed to evaluate the clinical outcomes of 3D-printed resin composite posterior fixed dental prosthesis (FDP) restorations. Between October 2020 and August 2022, 49 patients (33 females, 16 males, aged 19-60) received 68 3-unit 3D-printed resin composite posterior FDPs (ELS Even Stronger, Saremco, Switzerland). Follow-ups were conducted at baseline (2 weeks) by independent observers using modified FDI criteria, assessing anatomical form, marginal adaptation, surface roughness, color match, fracture, retention, and patient feedback. Fifty FDPs completed a 1-year follow-up, and 18 reached 2 years. The mean observation period was 14.15 months. Failures were categorized as mechanical or biological, with 19 FDPs failing: 14 mechanical (12 cohesive fractures) and 5 biological (3 needing endodontic treatment, 2 periodontal issues). Two FDPs were recemented. Three FDPs showed surface luster loss, color mismatches, and staining. The survival rate based on mechanical failures was 69.5%, dropping to 61.0% when including biological complications. After 2 years, 3D-printed resin composite FDPs demonstrated acceptable performance, with most failures due to fractures in the connector region, suggesting the need for design revisions.

WASTE EGGSHELL AND SAWDUST AS REINFORCEMENTS FOR SUSTAINABLE POLYESTER COMPOSITES: MECHANICAL CHARACTERIZATION AND ENVIRONMENTAL DURABILITY ASSESSMENT

This research endeavor undertakes an experimental investigation into the bending and tensile properties of polyester composites reinforced with waste eggshell powder and sawdust particles at 35 wt.%. Valorizing these waste materials as reinforcements contributes to sustainable practices, waste minimization, and environmental pollution mitigation. Composite samples were fabricated using hand lay-up and compression molding techniques. The effects of environmental exposure to water, acidic, and basic media immersion on the mechanical performance were evaluated to assess durability. Experimental characterization through tensile and three-point bending tests determined mechanical properties, stress-strain behavior, and failure mechanisms. Additionally, finite element analysis (FEA) simulations complemented the experiments by providing insights into stress distributions, deformations, and potential failure initiation sites within the composites under flexural loading. The computational models accurately captured the reinforcing effects of the waste materials and the degradation induced by environmental exposure, validating the experimental trends. Incorporating waste natural fibers significantly enhanced polyester's bending strength by 140% (sawdust) and 75% (eggshell), and tensile strength by 13% (sawdust) and 10% (eggshell). However, environmental exposure degraded properties to varying extents, with water immersion reducing tensile strength by 63% (sawdust) and 3% (eggshell), and flexural strength by 63% (sawdust) and 3% (eggshell). The acidic medium caused 58% (sawdust) and 23% (eggshell) reductions in tensile strength, and similar flexural strength degradations. Strikingly, the basic medium decreased eggshell composite tensile strength by 170% and flexural strength by 6%, while sawdust composite strengths declined by 44%.

Management of the Inflatable Penile Prosthesis Reservoir at time of revision surgery: remove, retain, or recycle?

Three common strategies exist for managing the inflatable penile prosthesis reservoir during revision surgery: the original reservoir can be (a) removed, (b) deactivated and left in situ, sometimes referred to as "drain and retain" (DR), or (c) validated and reconnected to new cylinders, which we have termed "reservoir recycling" (RR). To compare the efficacy and safety of the RR approach to penile prosthesis revision against DR and the recommended approach of complete device removal and replacement. A retrospective chart review of our single-surgeon inflatable penile prosthesis database between 2007 and 2022 was performed, identifying revision surgeries. Cases were stratified by reservoir management technique. Patients who had undergone at least 1 follow-up visit and had complete documentation regarding reservoir handling were included. Reservoir-related complications necessitating surgical intervention such as infection and device failure were compared between the 3 groups using a chi-square test. Mean follow-up duration, time to revision, and operative time were also assessed. The primary outcome was theincidence of reservoir-related complications requiring surgical intervention and secondary outcomes included time to revision surgery and operative time. Among 140 patients meeting inclusion criteria, 62 underwent full reservoir replacement (FR), 48 DR, and 30 RR. Compared to FR, DR and RR groups had similar mean time to revision and intraoperative time. Follow-up duration was similarly limited for all 3 groups at a median of approximately 4.5months. There were no postoperative infections in the RR cohort. However, when compared to the DR and FR groups, this did not reach significance (P = .398). There was no difference in mechanical failure rate between the 3 groups (P = .059). Nonmechanical failure was also similar between all 3 groups (P = .165). These results suggest that RR exhibits comparable outcomes to DR and FR, making it a viable option during select penile prosthesis revision surgeries, potentially decreasing morbidity without compromising outcomes. This is the first study to evaluate outcomes after RR. Limitations include small sample size, limited follow-up, and single-surgeon experience. There was no difference in reservoir-related complications when comparing the 3 methods. These preliminary results suggest that reservoir recycling may provide a safe and effective reservoir-handling alternative in inflatable penile prosthesis revision surgery.

Prepatellar bursa mucosa: An unreported postoperative complication of patellar fracture.

Patellar fracture is a common injury caused by overstrain of the extensor mechanism or a direct trauma to the knee. The most common complications after patellar fracture are nonunion, infection, post-traumatic arthritis, joint fibrosis, symptomatic hardware, and extensor mechanism failure. These are attributed to the post-fracture flexion and extension movements, the primary damage to the articular cartilage, and the thin soft tissue coverage over the knee. To our knowledge, prepatellar bursa mucosa is an unreported postoperative complication of patellar fracture. We describe a case of a 58-year-old woman with a left patellar fracture from a fall. Complete healing was achieved after in 2 months postoperatively using the improved Kirschner wire tension band and a cable grip system; however, at 7 months postoperatively, a prepatellar skin mass appeared. The patient reported prepatellar discomfort with no pain and influence of movement of the knee and daily life. One year postoperatively, we surgically removed the implants and mass. The pathological result showed bursa mucosa. The literature review shows that pain, secondary knee dysfunction, fracture nonunion, and malunion are postoperative complications of patellar fractures. However, prepatellar bursa mucosa have not been previously reported as a postoperative complication. This case highlights the need for appropriate placement of the intraoperative implant in adults with patellar fractures.

Metal implants in children.

Metal implants are increasingly used in children for trauma and deformity correction. This review outlines the current knowledge on the types of metals used and explores reasons for removal and the potential for long-term health issues of metal implants. The literature pertaining to these aspects was studied and summarised in this review. Types of metals used have evolved as well as the development of children-specific implants. Improvements in deformity correction are measurable with likely improved outcomes and reduced health costs. Indications for metal implant removal following successful treatment remain ill-defined; however, the risks of removal are known with a minimum 6% complication rate. Health costs could be reduced by around 6% by judicious decisions to leave metal in place. Implant removal should only be encouraged in the presence of infection, mechanical failure or symptoms that are truly attributable to the implant. In the domain of spinal implants, there is evidence of significant metal ion release, most notably titanium which remains elevated to many times baseline levels beyond 2 years. The detection of titanium at low levels requires special techniques. The long-term health effects on patients and/or their offspring are not well defined, although well described in animal models. The risks of metal removal are significant. Clinicians need to be aware of potential health risks in the use of metal implants and the potential for covert toxicity effects in children especially with their long life ahead. There is a need for greater awareness of metal alloy composition and implant design to minimise risks. Level V.

A numerical simulation study on the characteristics of wrap shell lightweight aggregate concrete based on random aggregate model

It is a way to reuse solid waste by using dredged silt as raw material to prepare unburned wrap shell lightweight aggregates and replacing crushed stone aggregate to prepare unburned wrap shell lightweight aggregates concrete specimen. In order to understand the characteristics of wrap shell lightweight aggregates concrete, this paper adopts the method of combining laboratory test and numerical simulation to design the mix ratio test scheme of concrete specimens with different substitution rates of wrap shell aggregate (0 %, 25 %, 50 %, 75 %, 100 %), and conducts indoor mechanical properties test and numerical simulation simulation test on them, so as to obtain and analyze the mechanical properties and failure characteristics.The results show that:(1) The peak stress intensity of concrete specimens decreases linearly with the increase of the substitution rate of wrap shell aggregate.(2) The peak stress of concrete under different wrap shell round aggregate substitution rates is normally distributed, and the dispersion of peak strength decreases with the increase of wrap shell aggregate substitution rate. When the substitution rate is 0 %, the dispersion of peak strength is the largest.(3) Under the uniaxial compression simulation test, the failure mode of concrete specimens changes with the addition of the substitution rate of wrap shell aggregate. When the crack failure occurs, natural coarse aggregate with high strength is chosen to bypass, while when it comes to wrap shell aggregate with low strength, it is chosen to penetrate. With the continuous addition of round aggregate, the stress concentration phenomenon inside concrete can be effectively improved and the number of micro-cracks can be reduced.But at the same time, the penetration cracks gradually increase and gradually tend to be straight.The fractal dimension is negatively correlated with the compressive strength and positively correlated with the substitution rate of wrap shell aggregate.The above research can provide theoretical basis for the popularization of recycled concrete with wrap shell aggregate.

Innovations in Energy Through Nanomaterials Enhancing Solid-State Battery Safety and Efficacy

This paper explores the potential of Si-based nanomaterials to enhance the performance of lithium-ion batteries (LIBs), particularly for electric vehicles (EVs). Traditional graphite anodes limit the energy density and range of EVs, increasing the need to search for alternative materials like silicon, which offers a much higher theoretical specific capacity. However, silicon’s application has been challenged by significant volume changes during cycling, leading to mechanical stress and failure. The use of nanotechnology, especially silicon nanomaterials, offers promising solutions to these challenges. Silicon nanostructures, such as nanowires, exhibit enhanced mechanical properties, allowing them to withstand volumetric changes and maintain high capacity during cycling. This review delves into the chemo-physical properties of silicon, the challenges posed by silicon anodes (SAs), and the recent advancements in silicon nanomaterials. Additionally, it also discusses different approaches to enhancing the performance of Si-based anodes, as well as the difficulties that exist now and the directions that future research in this exciting area is headed.

Smart Technology Integration: SHM and BIM for Preventing Building Collapses

Smart Technology Integration: SHM and BIM for Preventing Building Collapses

Enhancing fixation stability in proximal humerus fractures: screw orientation optimization in PHILOS plates through finite element analysis and biomechanical testing

The optimal treatment strategy for proximal humerus fractures (PHFs) is debatable owing to the relatively high failure rate of locking plates. Optimizing implants may enhance the fixation stability of PHFs and reduce the rate of mechanical failures. We developed a finite element (FE) model to simulate the treatment of PHFs with Proximal Humerus Internal Locking System (PHILOS) plates. The model evaluated the average bone strain around the screw tips under vertical loading (as an alternative to the risk of cyclic screw cutout failure verified through biomechanical testing) to minimize this strain and maximize predicted fixation stability. After determining the optimal screw configuration, further FE analysis and in vitro biomechanical testing were conducted on both standard and optimized PHILOS screw orientation to assess whether the optimized plates have biomechanical advantages over the standard plates. The FE-based optimized configuration exhibited significantly lower bone strain around the implant than the standard PHILOS screw orientation (− 17.24%, p < 0.001). In both FE analysis and in vitro biomechanical testing, the optimized PHILOS plates achieved significantly lower average bone strain around the screws (p < 0.05), more uniform stress distribution, and greater structural stiffness (p < 0.05) than the standard PHILOS screw orientation. Our results show that biomechanical performance of the PHILOS plates can be improved by altering the orientation of the locking screws. This approach may be useful for future patient-specific design optimization of implants for other fractures.

Research Progress on Solid-state Electrolyte Interface Problems in Lithium-ion Batteries

Nowadays, compared with traditional liquid batteries, solid-state batteries have the superiorities of higher energy density, power density and safety due to their solid electrolytes. However, a series of interfacial problems at solid-solid interface have always hindered the further development of solid-state batteries. Based on these problems, this paper firstly introduces the types of solid-state batteries and interface, secondly describes the mechanical failure principles of cathode interface and anode interface, and finally elaborates the corresponding modification strategies for cathode interface and anode interface. By adopting various improved measures for these interfacial problems, the progress of wider commercialization of solid-state batteries can be facilitated.