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Designs, Volume 9, Issue 2 (April 2025) – 27 articles

Cover Story (view full-size image): There is an increasing need for motion assistance in the aging population, with solutions with feasible design and functionality expected to aid in this regard. Among the available assistance devices, finger exoskeletons are necessary for motion exercises and rehabilitation therapies. In the present study, a new finger exoskeleton is designed with a parallel cable-driven structure for autonomous use by elderly and impaired users. The main advantages of this device can be seen in its operational efficiency and lightweight design, the latter of which also permits ease of wear through a fabric glove. The exoskeleton is characterized through performance analysis and validated in experimental tests using a laboratory prototype. View this paper
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39 pages, 15451 KiB  
Article
Monitoring Occupant Posture Using a Standardized Sensor Interface with a Vehicle Seat
by Alberto Vergnano, Alessandro Pelizzari, Claudio Giorgianni, Jan Kovanda, Alessandro Zimmer, Joed Lopes da Silva, Hamed Rezvanpour and Francesco Leali
Designs 2025, 9(2), 52; https://doi.org/10.3390/designs9020052 - 20 Apr 2025
Viewed by 105
Abstract
Car safety can be enhanced by enabling the Airbag Control Unit (ACU) to adaptively deploy different charges based on the occupant’s position once the crash occurs. In this context, monitoring the occupant’s position using a sensorized seat integrated with an Inertial Measurement Unit [...] Read more.
Car safety can be enhanced by enabling the Airbag Control Unit (ACU) to adaptively deploy different charges based on the occupant’s position once the crash occurs. In this context, monitoring the occupant’s position using a sensorized seat integrated with an Inertial Measurement Unit (IMU) offers a practical and cost-effective solution. However, certain challenges still need to be addressed. The adoption of sensorized seats in research and vehicle set-up is still under consideration. This study investigates an interface device that can be reconfigured to suit almost any seat model. This reconfigurability makes it easily adaptable to new vehicles under development and applicable to any passenger seat in the vehicle. This paper details the device’s design, including its programming using calibration and monitoring features, which significantly improves its reliability compared to earlier prototypes. Extensive testing through real driving experiments with multiple participants demonstrated an accuracy range of 45–100%. The testing involved both drivers and passengers, showcasing the device’s ability to effectively monitor various in-car scenarios. Full article
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23 pages, 4901 KiB  
Article
Multi-Objective Optimization Scheduling for Electric Vehicle Charging and Discharging: Peak-Load Shifting Strategy Based on Monte Carlo Sampling
by Jian Zheng, Jinglan Cui, Zhongmei Zhao, Guocheng Li, Cong Wang, Zeguang Lu, Xiaohu Yang and Zhengguang Liu
Designs 2025, 9(2), 51; https://doi.org/10.3390/designs9020051 - 17 Apr 2025
Viewed by 366
Abstract
The uncoordinated charging behaviors of electric vehicles (EVs) challenge the stable operation of the grid, e.g., increasing the peak-to-valley ratio of the grid and diminishing power supply reliability. A Monte Carlo sampling method is employed to develop a charging behavior model for EVs [...] Read more.
The uncoordinated charging behaviors of electric vehicles (EVs) challenge the stable operation of the grid, e.g., increasing the peak-to-valley ratio of the grid and diminishing power supply reliability. A Monte Carlo sampling method is employed to develop a charging behavior model for EVs to solve the problems raised by random charge mode. The probability densities of daily driving distance, initial charging time, charging power, and charging duration are incorporated and analyzed. The proposed model enables multiple random sample values for EVs, considering varying weather conditions and time-of-use electricity prices. For charge and discharge optimization, an EV charge and discharge scheduling model is constructed, aiming to balance multiple objective functions, including battery degradation costs, user charging costs, grid load fluctuations, and peak-to-valley differences. The weighting method is applied to transform the multi-objective framework into a single-objective comprehensive solution, facilitating the identification of optimal charge and discharge strategies. Results demonstrate that the Monte Carlo sampling can satisfactorily generate datasets with realistic characteristics on the driving range and charging initiation time of the EVs. Furthermore, the load results achieved through multi-objective optimization demonstrate that the proposed strategy effectively mitigates peak-to-valley disparities. The peak load reduction and trough load increment are 27.6% and 160.1%, respectively. Through post-peak load balancing, the average costs of each EV for daily charging and battery degradation are reduced to be 7.58 yuan and 15.68 yuan, respectively. This approach can significantly enhance the grid stability, simultaneously address the economic interests of users, and extend battery lifespan. Full article
(This article belongs to the Topic Advanced Electric Vehicle Technology, 2nd Volume)
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24 pages, 10535 KiB  
Article
Enabling Navigation and Mission-Based Control on a Low-Cost Unitree Go1 Air Quadrupedal Robot
by Ntmitrii Gyrichidi, Mikhail P. Romanov, Yuriy Yu. Tsepkin and Alexey M. Romanov
Designs 2025, 9(2), 50; https://doi.org/10.3390/designs9020050 - 15 Apr 2025
Viewed by 323
Abstract
Quadrupedal robots are now not just prototypes as they were a decade ago. This field now focuses on finding new application areas for robots rather than solving pure locomotion problems. Although the price of quadrupedal robots has decreased significantly during the last decade, [...] Read more.
Quadrupedal robots are now not just prototypes as they were a decade ago. This field now focuses on finding new application areas for robots rather than solving pure locomotion problems. Although the price of quadrupedal robots has decreased significantly during the last decade, it is still relatively high and can be considered as one of the limiting factors for research, especially for multi-agent scenarios involving multiple robots. This paper proposes a simple and easily reproducible approach to integrating the cheapest robot from the Unitree Go1 series with controllers running the ArduPilot firmware without disassembling the robot itself or modifying its hardware. Experimental studies show that the average latency introduced by the proposed control method over Wi-Fi is 206.7 ms, and its standard deviation is below 53 ms, which is suitable for following the mission route using the Global Navigation Satellite System (GNSS). At the same time, control using Ethernet reduces mean latency down to 78.3 ms and provides additional functionality (e.g., the ability to configure step height). Finally, in the range of standard Go1 speeds, both proposed control interfaces, based on Wi-Fi and Ethernet, are suitable for most practical indoor and outdoor tasks. Full article
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25 pages, 1061 KiB  
Article
A Simplified Approach to Geometric Non-Linearity in Clamped–Clamped Plates for Energy-Harvesting Applications
by Alessandro Fiorini, Francesco De Vanna, Marco Carraro, Stefano Regazzo and Giovanna Cavazzini
Designs 2025, 9(2), 49; https://doi.org/10.3390/designs9020049 - 14 Apr 2025
Viewed by 162
Abstract
Energy-harvesting devices utilizing the Vortex-Induced Vibration (VIV) phenomenon are gaining significant research attention due to their potential to generate energy from small water flows, where conventional hydroelectric plants are impractical. Developing effective design methods for these systems is therefore essential. This study focuses [...] Read more.
Energy-harvesting devices utilizing the Vortex-Induced Vibration (VIV) phenomenon are gaining significant research attention due to their potential to generate energy from small water flows, where conventional hydroelectric plants are impractical. Developing effective design methods for these systems is therefore essential. This study focuses on a critical configuration of such devices where energy extraction is achieved by harnessing the oscillatory deformation of two clamped–clamped plates, positioned downstream of the bluff body and subject to the effect of the vortex street. To simplify the preliminary design process, a semi-analytical approach, based on energetic considerations, is proposed to model the non-linear oscillations of the plates, eliminating the need for numerical simulations. The accuracy of this method is assessed through comparative analyses with finite element method (FEM) analyses, under both static and dynamic deformation conditions. The results validate the effectiveness of the proposed approach, offering insights into the effect of the adopted simplifications. In this framework, potential improvements to enhance the method’s reliability are identified. Thus, the work provides a practical model to address the preliminary design of these devices and suggests pathways for its further enhancement. Full article
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15 pages, 1884 KiB  
Article
Optimal Configuration Strategy Design for Offshore Wind Farm Energy Storage Systems Considering Primary Frequency Regulation and Black-Start Support Capabilities
by Yu Wang, Jianyong Zhao, Fuqiang Zhang, Zhen He, Junxing Zhang, Heng Nian and Wangcheng Xu
Designs 2025, 9(2), 48; https://doi.org/10.3390/designs9020048 - 12 Apr 2025
Viewed by 100
Abstract
This study focuses on the participation of energy storage in primary frequency regulation of offshore wind farms. A frequency regulation performance evaluation indicator is designed, and the black-start capability of the wind farm after shutdown is also considered. By equivalently processing the black-start [...] Read more.
This study focuses on the participation of energy storage in primary frequency regulation of offshore wind farms. A frequency regulation performance evaluation indicator is designed, and the black-start capability of the wind farm after shutdown is also considered. By equivalently processing the black-start time, a black-start capability evaluation indicator is designed. An energy storage strategy is adopted to balance power charging and discharging during the primary frequency regulation cycle. Considering the service life of energy storage batteries and the maximum number of charge/discharge cycles, a multi-objective comprehensive optimization model is proposed, which integrates frequency regulation performance, annual average investment cost of energy storage, black-start capability, and wind energy utilization rate. The designed model is solved using a genetic algorithm. Finally, a case study of an offshore wind farm is given to compare and analyze the primary frequency regulation with energy storage participation and the joint frequency regulation of wind and energy storage, which verifies the effectiveness of the proposed designed model and algorithm. Full article
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28 pages, 7402 KiB  
Review
LiDAR Innovations: Insights from a Patent and Scientometric Analysis
by Raj Bridgelall
Designs 2025, 9(2), 47; https://doi.org/10.3390/designs9020047 - 11 Apr 2025
Viewed by 277
Abstract
Light detection and ranging (LiDAR) sensors are critical for autonomous vehicles that require unparalleled depth sensing. However, traditional LiDAR designs face significant challenges, including high costs and bulky configurations, limiting scalability and mass-market adoption. By uniquely combining patent and scientometric analysis, this study [...] Read more.
Light detection and ranging (LiDAR) sensors are critical for autonomous vehicles that require unparalleled depth sensing. However, traditional LiDAR designs face significant challenges, including high costs and bulky configurations, limiting scalability and mass-market adoption. By uniquely combining patent and scientometric analysis, this study screened 188 recent LiDAR patents from a dataset of more than two million patents, uncovering strategies to enhance capability and reduce production costs. The key findings highlight the growing emphasis on solid-state architectures, modular designs, and integrated manufacturing processes as pathways to scalable and efficient LiDAR solutions. These insights bridge the gap between scientific advancements and practical implementation, providing stakeholders with a clear understanding of the technological landscape and emerging trends. By identifying future directions and actionable opportunities, this work supports the development of next-generation LiDAR systems, fostering innovation and enabling broader adoption across autonomous vehicles and other sectors. Full article
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17 pages, 7222 KiB  
Article
Flexibly Parameterizable Vehicle Dynamics Models
by Dániel Nemes and Sándor Hajdu
Designs 2025, 9(2), 46; https://doi.org/10.3390/designs9020046 - 9 Apr 2025
Viewed by 250
Abstract
The following article presents the longitudinal modeling and simulation of a generic electric vehicle. The purpose of the research is to describe the applied modeling procedures and their MATLAB solutions. Furthermore, the goal is to demonstrate how to build a framework for a [...] Read more.
The following article presents the longitudinal modeling and simulation of a generic electric vehicle. The purpose of the research is to describe the applied modeling procedures and their MATLAB solutions. Furthermore, the goal is to demonstrate how to build a framework for a MATLAB R2024b Simulink and Simscape model that facilitates future optimization and ensures modularity, thereby facilitating collaboration among different research groups. After presenting the applied vehicle dynamics model and the created framework, some additional application examples are presented for which the method has already been tested. Full article
(This article belongs to the Section Vehicle Engineering Design)
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20 pages, 2239 KiB  
Article
A Novel Lightweight Deep Learning Approach for Drivers’ Facial Expression Detection
by Jia Uddin
Designs 2025, 9(2), 45; https://doi.org/10.3390/designs9020045 - 3 Apr 2025
Viewed by 236
Abstract
Drivers’ facial expression recognition systems play a pivotal role in Advanced Driver Assistance Systems (ADASs) by monitoring emotional states and detecting fatigue or distractions in real time. However, deploying such systems in resource-constrained environments like vehicles requires lightweight architectures to ensure real-time performance, [...] Read more.
Drivers’ facial expression recognition systems play a pivotal role in Advanced Driver Assistance Systems (ADASs) by monitoring emotional states and detecting fatigue or distractions in real time. However, deploying such systems in resource-constrained environments like vehicles requires lightweight architectures to ensure real-time performance, efficient model updates, and compatibility with embedded hardware. Smaller models significantly reduce communication overhead in distributed training. For autonomous vehicles, lightweight architectures also minimize the data transfer required for over-the-air updates. Moreover, they are crucial for their deployability on hardware with limited on-chip memory. In this work, we propose a novel Dual Attention Lightweight Deep Learning (DALDL) approach for drivers’ facial expression recognition. The proposed approach combines the SqueezeNext architecture with a Dual Attention Convolution (DAC) block. Our DAC block integrates Hybrid Channel Attention (HCA) and Coordinate Space Attention (CSA) to enhance feature extraction efficiency while maintaining minimal parameter overhead. To evaluate the effectiveness of our architecture, we compare it against two baselines: (a) Vanilla SqueezeNet and (b) AlexNet. Compared with SqueezeNet, DALDL improves accuracy by 7.96% and F1-score by 7.95% on the KMU-FED dataset. On the CK+ dataset, it achieves 8.51% higher accuracy and 8.40% higher F1-score. Against AlexNet, DALDL improves accuracy by 4.34% and F1-score by 4.17% on KMU-FED. Lastly, on CK+, it provides a 5.36% boost in accuracy and a 7.24% increase in F1-score. These results demonstrate that DALDL is a promising solution for efficient and accurate emotion recognition in real-world automotive applications. Full article
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26 pages, 16189 KiB  
Review
State-of-the-Art Review of Hempcrete for Residential Building Construction
by Anthony C. Jellen and Ali M. Memari
Designs 2025, 9(2), 44; https://doi.org/10.3390/designs9020044 - 2 Apr 2025
Viewed by 1307
Abstract
Carbon-neutral and carbon-negative construction is gaining significant interest in the home building industry. Accordingly, the development of new materials and innovative redesign of the existing materials are on the rise. This paper presents the results of a review study on hempcrete as a [...] Read more.
Carbon-neutral and carbon-negative construction is gaining significant interest in the home building industry. Accordingly, the development of new materials and innovative redesign of the existing materials are on the rise. This paper presents the results of a review study on hempcrete as a new, emerging construction material, which is crop-based and is accordingly expected to provide a highly sustainable construction system. The paper reviews the mixture design, properties and attributes, different methods for its application in construction, building code requirements for construction of hempcrete homes, mechanical and structural properties for home building, and evaluation of the current state of hempcrete application as a non-load-bearing construction material. The paper also reviews the status of developments toward using hempcrete as a load-bearing system. The study shows a snapshot of the methods used for the construction of hempcrete buildings and touches on efforts that are ongoing to increase the compressive strength of hempcrete toward load-bearing applications. Such an increase would depend on different factors such as curing temperature and humidity, binder type and percentage, hemp-to-binder ratio, water-to-binder ratio, and additives. Full article
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33 pages, 13180 KiB  
Article
Design and Development of a High-Accuracy IoT System for Real-Time Load and Space Monitoring in Shipping Containers
by Luis Miguel Pires, Tiago Alves, Mikil Vassaramo and Vitor Fialho
Designs 2025, 9(2), 43; https://doi.org/10.3390/designs9020043 - 1 Apr 2025
Viewed by 635
Abstract
In a scenario where fuel costs are notably high and the policies that we are currently witnessing tend to limit the fossil fuel resource that powers most heavy goods transport services, the optimization of space in vehicles transporting these goods, such as trucks [...] Read more.
In a scenario where fuel costs are notably high and the policies that we are currently witnessing tend to limit the fossil fuel resource that powers most heavy goods transport services, the optimization of space in vehicles transporting these goods, such as trucks and shipping containers, becomes an indisputable and urgent need. This urgency is manifested in the need to minimize the costs associated with transport, given its increasing growth. This experiment aims to study and implement an Internet of Things (IoT)-based solution to the problem previously presented. The developed system comprises a computer and a millimeter-wave (mmWave) sensor. The computer processes the data captured by the sensor through code in Python language and displays, through a web page allocated in a cloud/server, the volume occupied by the load, as well as the percentage of occupied and free space, considering the volume provided by the user. The validation tests consisted of checking the results in 2D and 3D, all carried out in a controlled environment focused on the detection of static objects. For the 3D analysis, the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm was used to obtain the points for extracting the volume of the detected object. Several objects with different dimensions were used and the error ranged from 0.6% to 7.61%. These results denote the confirmation of the reliability and efficacy of the presented solution. With this, it was concluded that this new solution has significant potential to enter the market and compete with other existing technologies. Full article
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11 pages, 722 KiB  
Article
User-Centered Evaluation of the ARTH-Aid ExoGlove: Perspectives of Patients and Therapists in Rheumatoid Arthritis Rehabilitation
by Roberto Moya-Jiménez, Andrea Goyes-Balladares, Mario Rivera-Valenzuela and Teresa Magal-Royo
Designs 2025, 9(2), 42; https://doi.org/10.3390/designs9020042 - 1 Apr 2025
Viewed by 228
Abstract
In the field of rehabilitation exoskeletons, addressing the needs of users and healthcare professionals is essential for the development of effective medical technologies. This study presents a user-centered evaluation of the ARTH-aid ExoGlove, a proposed rehabilitation device for muscle atrophy caused by rheumatoid [...] Read more.
In the field of rehabilitation exoskeletons, addressing the needs of users and healthcare professionals is essential for the development of effective medical technologies. This study presents a user-centered evaluation of the ARTH-aid ExoGlove, a proposed rehabilitation device for muscle atrophy caused by rheumatoid arthritis. This study assesses usability and user experience through therapist and patient feedback, focusing on ergonomic and functional aspects. Ensuring compliance with usability and adaptability criteria is crucial before implementation to enhance effectiveness in clinical settings. While this study includes user feedback, further technical validation and refinement of the system are needed. The findings provide insights into patients’ perceptions of usability and impact on mobility, as well as therapists’ perspectives on its potential integration into rehabilitation protocols. These results highlight the importance of iterative validation and reinforce the role of rehabilitation technologies in complementing traditional therapeutic approaches and advancing patient-centered innovation in biomedical design. Full article
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24 pages, 1121 KiB  
Review
Review of Dynamic Building Envelope Systems and Technologies Utilizing Renewable Energy Resources
by Mohammad Almesbah and Julian Wang
Designs 2025, 9(2), 41; https://doi.org/10.3390/designs9020041 - 31 Mar 2025
Viewed by 341
Abstract
Dynamic building envelopes integrated with renewable energy sources, termed Dynamic and Renewable Source Building Envelopes (DREBE), provide an innovative approach to optimizing building envelope designs. Yet, these systems are not mature enough and not widely adopted in the industry and few literature resources [...] Read more.
Dynamic building envelopes integrated with renewable energy sources, termed Dynamic and Renewable Source Building Envelopes (DREBE), provide an innovative approach to optimizing building envelope designs. Yet, these systems are not mature enough and not widely adopted in the industry and few literature resources are employed to understand them. These systems dynamically respond and adapt to various environmental, energy, and occupancy demands for higher energy efficiency and comfort levels compared to traditional building envelopes while simultaneously producing energy. Their potential in climate change mitigation and fostering sustainable urban development warrants great attention from industry and urban planners. Especially in positive energy districts, which aim to reach net-positive energy goals through utilizing smart energy efficient building systems on the district level. This paper reviews innovative systems like dynamic photovoltaic shading devices and phase change materials and evaluates their performance by answering two research questions, what are the current DBE trends and are they feasible in achieving net-positive energy consumption? The analysis conducted reveals the dominance of solar-based dynamic renewable energy systems and a great need for alternatives. The study suggests that alternatives like wind as a renewable energy source should be studied with dynamic systems. Moreover, the study highlights current research gaps including insufficient data on long-term application and economic costs associated with such systems. To address this gap, the study suggests exploring in depth some of these systems and then branching into various combinations of dynamic envelope systems with multiple renewable or adaptive components to further enhance the overall building performance. By synthesizing the current body of literature, this paper gives insights into advancing the application of the dynamic building envelope systems and highlights their crucial role in the future of sustainable urban environments. Full article
(This article belongs to the Special Issue Design and Applications of Positive Energy Districts)
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34 pages, 15437 KiB  
Article
Numerical Investigation and Design Optimization of Centrifugal Water Pump with Splitter Blades Using Response Surface Method
by Justin Abuan and Jaime Honra
Designs 2025, 9(2), 40; https://doi.org/10.3390/designs9020040 - 31 Mar 2025
Viewed by 328
Abstract
Centrifugal pumps are known to efficiently transport water from a certain point. However, they developed great concerns in water supply and distribution applications regarding their operating efficiency, which were caused by the accumulated losses and sudden power consumption growth. Thus, mitigating these concerns [...] Read more.
Centrifugal pumps are known to efficiently transport water from a certain point. However, they developed great concerns in water supply and distribution applications regarding their operating efficiency, which were caused by the accumulated losses and sudden power consumption growth. Thus, mitigating these concerns is important to improve the performance of the centrifugal pump. This study used ANSYS 2022 R2 for the optimization design process, combining the strengths of Computational Fluid Dynamics (CFD) and Response Surface Method (RSM), to come up with an optimal design for a centrifugal water pump. Splitter blades, with a length of 80% of the main blade, were included in the design to assess their effects on the performance of the pump. Design parameters such as the placement of the splitter blades, their ellipse ratios, and the volute tongue, were also investigated for further improvement. Results indicate that finding a perfect balance between the placement of the splitter blades, the design of the volute tongue clearance and thickness, and configuring the ellipse ratio of the splitter blades improves the pump’s performance. The optimal design results in 27.35%, 15.70%, 28.18%, 16.67%, and 8.36% improvement in total efficiency, total head, static efficiency, static head, and power consumption, respectively. Full article
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32 pages, 4278 KiB  
Article
The Design Process in the Development of an Online Platform for Personalizing Wearable Prostheses: A Preliminary Approach
by Sara Peixoto, Nuno Martins, Daniel Miranda, Demétrio Matos and Vítor Carvalho
Designs 2025, 9(2), 39; https://doi.org/10.3390/designs9020039 - 31 Mar 2025
Viewed by 301
Abstract
This study is part of the research project Dep-Project: Design and Embodiment of Wearable Prostheses, funded by the Foundation for Science and Technology (FCT), whose main objective is the development of wearable myoelectric prostheses for upper limbs, which are economically accessible, socially [...] Read more.
This study is part of the research project Dep-Project: Design and Embodiment of Wearable Prostheses, funded by the Foundation for Science and Technology (FCT), whose main objective is the development of wearable myoelectric prostheses for upper limbs, which are economically accessible, socially accepted, and personalizable. In this context, the need arose to create an online platform with an intuitive interface, which would facilitate the access to persons with upper limb amputation to information about prosthetics and allow them to personalize their prosthesis, according to their aesthetic preferences. Thus, this work aims to demonstrate the importance of designing interfaces for greater inclusion, as well as demonstrating and describing the efficiency of the design process adopted with the aim of potentially being adopted in similar cases. The methodology adopted was Design Thinking, an approach centered on user needs. The development of the platform involved the creation of user personas, information architecture, user flows, wireframes, wireflows, and a design system. The interactive prototype underwent usability testing to evaluate the user experience and identify possible areas for improvement. The results, obtained through the System Usability Scale (SUS) post-test questionnaire, revealed a high success rate, which confirmed the efficiency of the designed solution. Full article
(This article belongs to the Section Smart Manufacturing System Design)
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27 pages, 3145 KiB  
Review
Potential Designs for Miniature Distributed Optical Fiber Smart Sensors Systems for Use in Aerospace Flight Vehicles
by Graham Wild
Designs 2025, 9(2), 38; https://doi.org/10.3390/designs9020038 - 26 Mar 2025
Viewed by 351
Abstract
This article explores the feasibility of miniaturizing and packaging fiber Bragg grating (FBG)-based distributed optical fiber smart sensors (DOFSS) for future flight trials. It highlights the importance of real-time, high-speed sensing in aerospace, particularly for hypersonic vehicles, and the challenges of conventional system [...] Read more.
This article explores the feasibility of miniaturizing and packaging fiber Bragg grating (FBG)-based distributed optical fiber smart sensors (DOFSS) for future flight trials. It highlights the importance of real-time, high-speed sensing in aerospace, particularly for hypersonic vehicles, and the challenges of conventional system integration. The advantages of FBG technology for structural health monitoring, temperature, and pressure sensing are examined. Potential systems, including light sources, spectral detection, and processing units, are discussed, along with challenges such as temperature fluctuations and vibrations. Innovations in photonic devices, fabrication, and packaging are emphasized, focusing on developing compact and robust FBG interrogation systems. The article proposes designs for integrated photonic circuits in FBG interrogation systems. The trade-offs between miniaturization and performance, considering sensitivity, resolution, and durability are also assessed. Finally, future research directions are outlined to enhance the sensitivity, resolution, and robustness of FBG interrogators while enabling miniaturization and multifunctionality. The article concludes by summarizing the potential for miniaturizing and packaging FBG-based DOFSS for aerospace flight trials. Full article
(This article belongs to the Section Mechanical Engineering Design)
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19 pages, 25350 KiB  
Article
Design of an Experimental System for the Assessment of the Drug Loss in Drug-Coated Balloons Due to Washing Off During Tracking
by Dimitrios Zantzas, Elena Bianchi, Francesca Berti, Mohammad Akrami-Hasan-Kohal, Tahmer Sharkawi and Giancarlo Pennati
Designs 2025, 9(2), 37; https://doi.org/10.3390/designs9020037 - 24 Mar 2025
Viewed by 296
Abstract
Drug-coated balloons (DCBs) are designed to deliver an anti-proliferative drug to the stenotic vessel to combat restenosis after an angioplasty treatment. However, significant drug loss can occur during device navigation toward the lesion site, thus reducing the delivery efficiency and increasing the off-target [...] Read more.
Drug-coated balloons (DCBs) are designed to deliver an anti-proliferative drug to the stenotic vessel to combat restenosis after an angioplasty treatment. However, significant drug loss can occur during device navigation toward the lesion site, thus reducing the delivery efficiency and increasing the off-target drug loss. In this framework, this study aimed to design a novel in vitro setup to estimate the drug loss due to blood flow–coating interaction during tracking. The system consists of a millifluidic chamber, able to host small drug-coated flat patches representative of DCBs, connected at the inlet to a syringe pump able to provide an ad hoc flow and, at the outlet, to a vial collecting the testing fluid with possible drug removed from the specimen. Unlike other studies, the device presented here uniquely evaluates flow-related drug loss from smaller-scale DCB samples, making it a precise, easy-to-use, and efficient assessment tool. In order to define proper boundary conditions for these washing off tests, computational fluid dynamics (CFD) models of a DCB in an idealized vessel were developed to estimate the wall shear stresses (WSSs) experienced in vivo by the device when inserted into leg arteries. From these simulations, different target WSSs were identified as of interest to be replicated in the in vitro setup. A combined analytical–CFD approach was followed to design the testing system and set the flow rates to be imposed to generate the desired WSSs. Finally, a proof-of-concept study was performed by testing eight coated flat specimens and analyzing drug content via high-performance liquid chromatography (HPLC). Results indicated different amounts of drug loss according to the different imposed WSSs and confirmed the suitability of the designed system to assess the washing off resistance of different drug coatings for angioplasty balloons. Full article
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22 pages, 5756 KiB  
Article
Shaping Design Decisions for Mechatronic Systems by Integrating Environmental Considerations Using Simplified Life Cycle Assessment and Colored Petri Nets
by Imane Mehdi, El Mostapha Boudi and Mohammed Amine Mehdi
Designs 2025, 9(2), 36; https://doi.org/10.3390/designs9020036 - 18 Mar 2025
Viewed by 286
Abstract
Decisions made during the design phase of mechatronic systems have a considerable influence on their entire life cycle. The persistent calls for environmental protection are driven by global megatrends promoting sustainability. Hence, opting for eco-designed mechatronic systems is now a fundamental cornerstone of [...] Read more.
Decisions made during the design phase of mechatronic systems have a considerable influence on their entire life cycle. The persistent calls for environmental protection are driven by global megatrends promoting sustainability. Hence, opting for eco-designed mechatronic systems is now a fundamental cornerstone of manufacturers’ strategies. This paper is a generalization of the environmental assessment step of a sustainable design methodology applied to mechatronic systems with structural design freeze, which is only relevant for a limited set of admissible mechatronic solutions. The approach is adapted to cover any dimension of admissible solutions using hierarchical timed colored Petri nets (hierarchical TCPN) and simplified life cycle assessments (SLCAs). First, the SLCAs results are integrated into the hierarchical TCPN model. Next, a weighting process is introduced to ensure the classification of the heterogeneous impact categories derived from SLCAs according to agreed impact reduction criteria. Then, the candidate ecological solution and its design environmental matrix (DEM) are determined via simulations. The methodology is implemented using a regenerative braking system (RBS) with frozen structural specifications, focusing on its production phase and using CPN tools and OpenLCA software. It enables the selection of the candidate ecological RBS among a large set of admissible solutions. This selection is established without interrupting the normal design process but simply by adding an extra step. Full article
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18 pages, 6575 KiB  
Article
Design of a Cable-Driven Finger Exoskeleton
by Marco Ceccarelli, Thibault Vaisson and Matteo Russo
Designs 2025, 9(2), 35; https://doi.org/10.3390/designs9020035 - 18 Mar 2025
Viewed by 392
Abstract
Motion assistance is a growing need that is linked to the aging of the population, and solutions are required with adequate structures and functionality. Specific attention is paid to finger exoskeletons both for motion exercises and for rehabilitation therapies. The paper presents a [...] Read more.
Motion assistance is a growing need that is linked to the aging of the population, and solutions are required with adequate structures and functionality. Specific attention is paid to finger exoskeletons both for motion exercises and for rehabilitation therapies. The paper presents a new finger exoskeleton structure that is designed with a parallel cable-driven structure with adequate functionality for autonomous use by users. The main advantages can be appreciated in the operational efficiency in assisting finger motion and lightness of the design that also permits easy wearing with the proposed solution installed on a fabric glove. The exoskeleton is designed with a functional characterization through performance analysis thanks to a laboratory prototype that is built for experimental validation tests. The presented prototype appears to be easy to wear and operate with wide possibilities of implementation for motion exercises in rehabilitation and for elderly people. Full article
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26 pages, 2970 KiB  
Article
Evaluating Seismic Isolation Design: Simplified Linear Methods vs. Nonlinear Time-History Analysis
by Elias Yaacoub, Roberto Nascimbene, Marco Furinghetti and Alberto Pavese
Designs 2025, 9(2), 34; https://doi.org/10.3390/designs9020034 - 17 Mar 2025
Cited by 1 | Viewed by 520
Abstract
Seismic isolation is a vital strategy for improving the earthquake resilience of structures, utilizing flexible components such as lead–rubber bearings (LRBs) and curved surface sliders (CSSs) to attenuate ground motion effects. This paper presents a comprehensive comparative analysis of seismic isolation design methodologies [...] Read more.
Seismic isolation is a vital strategy for improving the earthquake resilience of structures, utilizing flexible components such as lead–rubber bearings (LRBs) and curved surface sliders (CSSs) to attenuate ground motion effects. This paper presents a comprehensive comparative analysis of seismic isolation design methodologies prescribed in the U.S. code (ASCE 7-22) and the European code (EC8). The focus is on the equivalent lateral force method, also known as the simplified linear method, renowned for its simplicity and efficiency in seismic design applications. A six-story steel building serves as a case study to examine the discrepancies between the two codes. The structure was modeled and subjected to nonlinear time-history analysis (NTHA) using 20 ground motion records, selected and scaled to match a conditional mean spectrum (CMS). Key performance indicators—including displacement at the isolation level, base shear forces, story shear forces, and story drifts—were compared to assess the reliability and effectiveness of each code’s design approach. The findings reveal notable differences between ASCE 7-22 and EC8, particularly in seismic hazard characterization and the calculation of design displacements. ASCE 7-22 generally adopts a more conservative stance, especially for CSSs, resulting in overestimations of design displacements and lateral seismic forces. In contrast, EC8’s simplified method aligns more closely with observed performance for LRBs. However, when applied to CSSs, simplified methods prove less reliable, underscoring the need for more precise analytical techniques. Full article
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22 pages, 9803 KiB  
Article
Guidelines for Design and Additive Manufacturing Specify the Use of Surgical Templates with Improved Accuracy Using the Masked Stereolithography Technique in the Zygomatic Bone Region
by Paweł Turek, Paweł Kubik, Dominika Ruszała, Natalia Dudek and Jacek Misiura
Designs 2025, 9(2), 33; https://doi.org/10.3390/designs9020033 - 12 Mar 2025
Viewed by 467
Abstract
The zygomatic bone area experiences frequent mechanical damage in the middle craniofacial region, including the orbital floor. The orbital floor bone is very thin, ranging from 0.74 mm to 1.5 mm. Enhancing digitization, reconstruction, and CAD modeling procedures is essential to improving the [...] Read more.
The zygomatic bone area experiences frequent mechanical damage in the middle craniofacial region, including the orbital floor. The orbital floor bone is very thin, ranging from 0.74 mm to 1.5 mm. Enhancing digitization, reconstruction, and CAD modeling procedures is essential to improving the visualization of this structure. Achieving a homogeneous surface with high manufacturing accuracy is crucial for developing precise surgical models and tools for creating titanium mesh implants to reconstruct the orbital floor geometry. This article improved the accuracy of reconstruction and CAD modeling using the example of the development of a prototype implant to replace the zygomatic bone and a tool to form the geometry of the titanium mesh within the geometry of the orbital floor. The masked stereolithography (mSLA) method was used in the model manufacturing process because it is low-cost and highly accurate. Two manufacturing modes (standard and ultra-light) were tested on an Anycubic Photon M3 Premium 3D printer to determine which mode produced a more accurate representation of the geometry. To verify the geometric accuracy of the manufactured models, a GOM Scan1 structured light scanner was used. In the process of evaluating the accuracy of the model preparation, the maximum deviation, mean deviation, range and standard deviation were determined. The maximum deviations for anatomical structures created using the normal mode ranged from ±0.6 mm to ±0.7 mm. In contrast, models produced with the ultra-light mode showed deviations of ±0.5 mm to ±0.6 mm. Furthermore, the results indicate that the ultra-light mode offers better surface accuracy for die and stamp models. More than 70% of the surface of the models is within the deviation range of ±0.3 mm, which is sufficient for planning surgical procedures. However, the guidelines developed in the presented publication need to optimize the CAD process and select 3D-printing parameters to minimize deviations, especially at the edges of manufactured models. Full article
(This article belongs to the Special Issue Design Process for Additive Manufacturing)
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22 pages, 13198 KiB  
Article
Design of an Environment for Virtual Training Based on Digital Reconstruction: From Real Vegetation to Its Tactile Simulation
by Alessandro Martinelli, Davide Fabiocchi, Francesca Picchio, Hermes Giberti and Marco Carnevale
Designs 2025, 9(2), 32; https://doi.org/10.3390/designs9020032 - 10 Mar 2025
Viewed by 452
Abstract
The exploitation of immersive simulation platforms to improve traditional training techniques in the agricultural industry sector would enable year-round accessibility, flexibility, safety, and consistent high-quality training for agricultural operators. An innovative workflow in virtual simulations for training and educational purposes includes an immersive [...] Read more.
The exploitation of immersive simulation platforms to improve traditional training techniques in the agricultural industry sector would enable year-round accessibility, flexibility, safety, and consistent high-quality training for agricultural operators. An innovative workflow in virtual simulations for training and educational purposes includes an immersive environment in which the operator can interact with plants through haptic interfaces, following instructions imparted by a non-playing character (NPC) instructor. This study allows simulating the pruning of a complex case study, a hazelnut tree, reproduced in very high detail to offer agricultural operators a more realistic and immersive training environment than those currently existing. The process of creating a multisensorial environment starts with the integrated survey of the plant with a laser scanner and photogrammetry and then generates a controllable parametric model from roots to leaves with the exact positioning of the original branches. The model is finally inserted into a simulation, where haptic gloves with tactile resistance responsive to model collisions are tested. The results of the experimentation demonstrate the correct execution of this innovative design simulation, in which branches and leaves can be cut using a shear, with immediate sensory feedback. The project therefore aims to finalize this product as a realistic training platform for pruning, but not limited to it, paving the way for high-fidelity simulation for many other types of operations and specializations. Full article
(This article belongs to the Special Issue Mixture of Human and Machine Intelligence in Digital Manufacturing)
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28 pages, 30346 KiB  
Article
Delta IXI: Deployable Structure with Flax Fibre Pultruded Profiles for Architectural Applications—Case Studies in Furniture and Adaptive Facade Systems
by Indiana Courarie-Delage, Evgenia Spyridonos and Hanaa Dahy
Designs 2025, 9(2), 31; https://doi.org/10.3390/designs9020031 - 7 Mar 2025
Viewed by 512
Abstract
Material selection is essential for advancing sustainability in construction. Biocomposites contribute significantly to raising the awareness of materials derived from biomass. This paper explores the design development and application of novel natural fibre pultruded biocomposite profiles in a deployable system. Development methods include [...] Read more.
Material selection is essential for advancing sustainability in construction. Biocomposites contribute significantly to raising the awareness of materials derived from biomass. This paper explores the design development and application of novel natural fibre pultruded biocomposite profiles in a deployable system. Development methods include geometrical studies to create a system that transforms from flat to three-dimensional. Physical and digital models were used to refine the geometry, while connection elements were designed to suit material properties and deployability requirements. The first case study, at a furniture scale, demonstrates the use of the profiles connected using threading methods to create a lightweight multifunctional deployable system enabling easy transport and storage. This system can be locked at various heights for different purposes. The realised structure weighs 4 kg, supporting weights up to 150 kg. The second case study applies the system architecturally in an adaptive kinetic facade, adjusting to the sun’s position for optimal shading, providing up to 70% daylight when open and as little as 20% when closed. These two structures validate the developed deployable system, showcasing the versatility of biocomposite profiles in such configurations. This approach enhances sustainability in architecture by enabling lightweight, adaptable, and eco-friendly building solutions. Full article
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20 pages, 6229 KiB  
Article
Experimental Study of Wear Resistance Improvement of Modular Disk Milling Cutter by Preliminary Pre-Processing Method
by Karibek Sherov, Almat Sagitov, Gulim Tusupbekova, Aibek Sherov, Gulnara Kokayeva, Dinara Kossatbekova, Gulnur Abdugaliyeva and Nurgul Karsakova
Designs 2025, 9(2), 30; https://doi.org/10.3390/designs9020030 - 5 Mar 2025
Viewed by 553
Abstract
The problem of increasing the tool durability (service life) when machining hard-to-machine materials is one of the major practical problems of modern mechanical engineering. This paper aims to improve the wear resistance of modular disk mills using the pre-processing method. Second-order rotatable planning [...] Read more.
The problem of increasing the tool durability (service life) when machining hard-to-machine materials is one of the major practical problems of modern mechanical engineering. This paper aims to improve the wear resistance of modular disk mills using the pre-processing method. Second-order rotatable planning was applied for the experimental study of the pre-processing of modular disk mills. Experimental research on the pre-processing of modular disk mills was carried out on a vertical milling machine XH950A when milling a workpiece made of steel 45. It was revealed that the increase in pre-processing modes up to specific values (f = 60 mm/min; vc = 17 m/min; t = 6 min) on the tool durability period has a positive effect. At the same time, the tool durability period was increased up to T = 155 min. Tests of the machined modular disk mills were carried out in the conditions of the laboratory base to determine the durability period. After pre-processing at different modes, each modular disk mill was used to machine the workpiece until wear signs appeared on the cutting edge. At the same time, the time was recorded to determine the durability period. It was found that the optimum mode of tool preliminary pre-processing provides the best deformation and thermal conditions for hardening the tool cutting part. As a result of modeling with the ANSYS 2024 R1 program, it was found that a hardened layer is indeed formed on the cutting part of the modular disk mill after pre-processing. The results obtained show the possibility of using the preliminary pre-processing method to improve the wear resistance of other metal-cutting tools. Full article
(This article belongs to the Section Mechanical Engineering Design)
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28 pages, 19792 KiB  
Article
Flexcork—Sustainable Helmet Designed for Electric Micromobility
by Miguel Mingote, Gabriel F. Serra, Eduardo J. H. Noronha and Fábio A. O. Fernandes
Designs 2025, 9(2), 29; https://doi.org/10.3390/designs9020029 - 4 Mar 2025
Viewed by 613
Abstract
Micromobility is a topic of growing interest, powered by the introduction of shared electric bicycles and, especially, e-scooters. This type of mobility has recently gained a lot of popularity in large cities, bringing many benefits, such as greener mobility, a connection for first- [...] Read more.
Micromobility is a topic of growing interest, powered by the introduction of shared electric bicycles and, especially, e-scooters. This type of mobility has recently gained a lot of popularity in large cities, bringing many benefits, such as greener mobility, a connection for first- and last-mile trips, and on-demand transportation alternatives. However, it also comes at the cost of inadequate infrastructure and laws. This created problems, mainly a concerning rise in accidents and consequent injuries. This study first identifies the main causes of accidents and injuries by defining key aspects such as vehicle types, user demographics, and prevalent injuries. Head injuries emerge as the most critical concern, largely due to low helmet usage across various studies. To address this issue, the barriers to helmet adoption are explored in order to develop a new concept aligned with micromobility needs. The proposed helmet design also prioritises sustainability by replacing petroleum-based materials with expanded cork. This alternative reduces carbon emissions while maintaining the desired performance. Additionally, the design follows principles of disassembly, eliminating adhesives and permanent joints to enhance recyclability. The result is a malleable structured helmet that adapts to user requirements while supporting the United Nations’ 2030 sustainability development goals. Full article
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13 pages, 4670 KiB  
Article
Development and Dynamic Numerical Evaluation of a Lightweight Sports Helmet Using Topology Optimization and Advanced Architected Materials
by Nikolaos Kladovasilakis, Konstantinos Tsongas, Eleftheria Maria Pechlivani and Dimitrios Tzetzis
Designs 2025, 9(2), 28; https://doi.org/10.3390/designs9020028 - 28 Feb 2025
Viewed by 505
Abstract
Sports activities often carry a high risk of injury, varying in severity, making the use of protective equipment, such as helmets and kneecaps, essential in many cases. Among all potential injuries, head injuries are the most crucial due to their severity. Hence, in [...] Read more.
Sports activities often carry a high risk of injury, varying in severity, making the use of protective equipment, such as helmets and kneecaps, essential in many cases. Among all potential injuries, head injuries are the most crucial due to their severity. Hence, in the last decades, the scientific interest has been focused on establishing head injury criteria and improving the helmet design with the ultimate goal of the reduction in injury probability and increasing the athlete’s performance. In this context, the current study aims to develop a lightweight sports helmet with increased safety performance, utilizing topology optimization processes and advanced architected materials. In detail, the design of a conventional helmet was developed and modified applying in specific regions advanced architected materials, such as triply periodic minimal surfaces (TPMS) and hybrid structures, with functionally graded configurations to produce sandwich-like structures capable of absorbing mechanical energy from impacts. The developed helmet’s designs were numerically evaluated through dynamic finite element analyses (FEA), simulating the helmet’s impact on a wall with a specific velocity. Through these analyses, the plastic deformation of the designed helmets was observed, coupled with the stress concentration contours. Furthermore, the results of FEAs were utilized in order to calculate the values of the head injury criterion (HIC). Finally, the developed topologically optimized helmet design incorporating the hybrid lattice structure revealed increased energy absorption, reaching a HIC of 1618, improved by around 14% compared to the conventional design configuration. Full article
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24 pages, 1426 KiB  
Article
A User Journey: Development of Drone-Based Medication Delivery—Meeting Developers and Co-Developers’ Expectations
by Anne Lehmann, Ivonne Kalter, Patrick Jahn and Franziska Fink
Designs 2025, 9(2), 27; https://doi.org/10.3390/designs9020027 - 27 Feb 2025
Viewed by 523
Abstract
This study builds on initial ADApp research that identified the factors that influence the intention to use a pharmacy drone app for urgent medication delivery. While previous studies and theories have predominantly focused on user acceptance alone, the present qualitative study introduced a [...] Read more.
This study builds on initial ADApp research that identified the factors that influence the intention to use a pharmacy drone app for urgent medication delivery. While previous studies and theories have predominantly focused on user acceptance alone, the present qualitative study introduced a holistic model that integrates user acceptance theories as well as user-centered design principles and technology features. It focused on the user journey to derive core statements from the development of a drone-based application using a qualitative theory synthesis approach (study 1), and explored the perceived participatory collaboration between developers (software and drone developers) and co-developers (core group participants) using final tandem discussions and a qualitative content analysis method (study 2). Study 1 resulted in the identification of eight categories that serve as technical working goals for future participatory technology development. Study 2 identified five critical factors that provide insight into the unique challenges and goals of collaborative development. Both studies contribute to a better understanding of the essential factors that lead to successful participatory processes between developers and co-developers aimed at increasing usability and intention to use. Based on these findings, an integrated model is presented to support participatory design strategies in healthcare technology development. Full article
(This article belongs to the Collection Editorial Board Members’ Collection Series: Drone Design)
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12 pages, 1144 KiB  
Article
Optimized Green Unrelated Parallel Machine Scheduling Problem Subject to Preventive Maintenance
by Najat Almasarwah
Designs 2025, 9(2), 26; https://doi.org/10.3390/designs9020026 - 25 Feb 2025
Viewed by 387
Abstract
Manufacturing areas typically conduct machine maintenance to prevent early failures and to ensure a safe working environment and efficient production. In this study, the green unrelated parallel machine scheduling problem (GUPMSP) is studied. Besides preventive maintenance, machine availability and non-preemption are considered. A [...] Read more.
Manufacturing areas typically conduct machine maintenance to prevent early failures and to ensure a safe working environment and efficient production. In this study, the green unrelated parallel machine scheduling problem (GUPMSP) is studied. Besides preventive maintenance, machine availability and non-preemption are considered. A globally optimal solution (mathematical model) and local optimal solution (a modified Moore heuristic algorithm) are used to optimize the number of products returned early in the GUPMSP. Three datasets, namely, a most favorable case, an average case, and a least favorable case, are created to test the performance of the two solutions’ approaches. The results demonstrate the ability of the mathematical model to dominate the results of the modified Moore’s algorithm in the tested datasets. However, optimizing the number of products returned early in the UPMSP with preventive maintenance reduces costs as a step to support the concept of sustainability and enhance efficiency. Full article
(This article belongs to the Topic Distributed Optimization for Control, 2nd Edition)
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