Scalability gaps in Engineering

Representative open questions

Showing 30 of 62 — one per source paper, highest-quality first.

• Sophisticated control design for direct drive permanent magnet synchronous generator-based wind turbines under voltage sags (2026) · doi

  The systematic controller parametrization procedure and BWKOA optimization approach were validated exclusively on a single PMSG-based wind turbine configuration with specific rated power (9.73 MW) and DC link voltage (6.5 kV). Scalability of the proposed design methodology to turbines with significantly different power ratings, generator specifications, and grid interconnection architectures remains unvalidated.

• Eutectogel-Based Drug Delivery Systems: Recent Advancements and Pharmaceutical Applications (2026) · doi

  Continuous, solvent-free, or standardized production methods for eutectogels have not been developed at scale; upscaling processes such as 3D printing and electrospinning for eutectogel drug delivery systems require validation to maintain consistent composition, mechanical strength, and solvent retention.

• Metal repair using hybrid additive manufacturing process: A comparative study of interfacial surface roughness for improved mechanical strength (2026) · doi

  The FE model was only applied to flat interfaces in bimetallic specimens under tensile loading. The authors explicitly identify the need to extend the model to non-flat interfaces with increased contact area and alternative repair geometries, which remain untested and would improve practical applicability to complex component repair scenarios.

• A Review on Engineering Approaches to Reverse Osmosis Brine Management: Disposal, Volume Reduction and Emerging Resource Recovery (2026) · doi

  Recovery of trace elements (lithium and rubidium) from seawater reverse osmosis brines remains constrained to laboratory and pilot-scale investigations and has not been demonstrated at commercial scales. Engineering approaches for selective ion extraction at the concentrations present in desalination brines are underdeveloped.

• Advances of artificial intelligence applications to low-carbon metallurgy of iron and steel (2026) · doi

  Graph neural networks with semi-supervised multi-modal fusion for few-shot steel strip defect detection have been proposed, but their scalability to production-line speed imaging and applicability across different strip thicknesses, surface finishes, and defect size distributions requires empirical testing.

• Revisiting the Modification Strategies of Alloy-Base Anode for Solid-State Lithium-Ion Batteries Through Deconstructing Anode-Interface-Solid Electrolyte (2026) · doi

  The Si@MOF symmetric cell demonstrated stable cycling for 1200 h at 0.2 mA cm⁻², but performance at higher current densities (≥1.0 mA cm⁻²) and longer cycle numbers (>500 cycles in full cells) with quantified capacity fade mechanisms for PVDF-fiber-supported composite electrolytes remains unvalidated for practical high-power solid-state lithium-ion battery commercialization.

• Design Optimization of an Additively Manufactured Passive Vibration Isolator for an Inertial Measurement Unit for Enhanced Measurement Performance (2026) · doi

  The optimization study minimizes natural frequency difference (achieving ~80Hz spread in nonlinear analysis) to decouple modes; however, the sensitivity of isolation performance to manufacturing tolerances in TPU rib dimensions and PLA ring geometry has not been systematically investigated.

• Physics-Informed Symbolic Regression Ensemble (PISRE) for surface roughness prediction in Ti-6Al-4V dry turning (2026) · doi

  The paper demonstrates PISRE-NF performance on a small-sample LOO cross-validation (n=19); scalability and stability of the uncertainty-weighted ensemble mechanism and Ridge regularisation have not been evaluated on larger datasets (n > 100) with higher-dimensional input spaces typical of industrial multi-parameter turning studies.

• Smart Baby Cradle Monitoring System (2026) · doi

  The ESP32 microcontroller with Wi-Fi/Bluetooth/BLE capabilities is selected for wide-range applications, but the paper does not evaluate power consumption profiles, battery life under continuous sensor polling and wireless transmission, or energy optimization strategies for a portable cradle system.

• Multifunctional zinc-ion capacitors for energy storage (2026) · doi

  Green and scalable preparation methods for zinc-ion capacitor materials, particularly MXenes, are urgently needed to address current industrial scalability barriers. Current MXene synthesis requires high-concentration acidic environments with low yield and generates costly, environmentally hazardous acid waste, requiring development of alternative synthesis routes.

• A review of additive manufacturing techniques for wind turbine blade production: capabilities, AI integration, and Scale-Up Potential (2026) · doi

  AI-driven closed-loop manufacturing systems integrating real-time defect detection, process optimization, and adaptive control for wind turbine blade AM have not been demonstrated at industrial scale. Development and validation of integrated closed-loop control architectures requires systematic testing in utility-scale production environments.

• Performance Evaluation of Electric Vehicles Using PSO and AHA Based Optimal Control Methodology (2026) · doi

  The paper does not address computational complexity or real-time implementation feasibility of the AHA algorithm on embedded vehicle control units; processor requirements, execution time constraints, and hardware compatibility for in-vehicle deployment remain unspecified.

• Design of a green ammonia production process by machine learning (2026) · doi

  The study optimized the four-bed adiabatic indirect cooling reactor configuration under a fixed 10 MW power constraint, but does not explore how the GPR model and BO algorithm performance scales when applied to different reactor types, cooling mechanisms, or variable power constraints ranging from 5-20 MW.

• Recent advances in polyoxothiometalate chemistry (2022) · doi

  Molecular molybdenum sulfide catalysts and POTM clusters have achieved HER overpotentials down to -114 to -120 mV, but scalability testing on bulk electrodes or electrode materials and long-term stability/degradation pathways under operational conditions remain unaddressed for polyoxothiometalate HER catalysts.

• AI-driven adaptive vibration control in smart plate systems: a sustainable approach for next-generation sports engineering (2026) · doi

  While the study analyzes relative frequency change across geometric ratios and voltage levels, it does not address how in-plane voltage sensitivity of natural frequency scales to large-format or non-rectangular composite plate geometries used in actual sports equipment.

• Electron transfer mechanism in microbial fuel cells (2026) · doi

  Scaling of MFC systems from laboratory reactors to industrial-scale chambers requires validation of electron transfer mechanisms and bioelectricity production stability; performance data for large-scale MFC configurations operating at high voltage and current outputs using series connection of cells is currently unavailable.

• Small-scale water energy harvesting for sustainably-powered distributed electronics (2026) · doi

  The output power of moisture-enabled electrochemical generators (MODEG) remains limited by humidity gradient and membrane structure constraints, preventing reliable operation of higher energy consumption wireless sensing functions in wearable applications.

• Topotactic engineering of high-entropy (oxy) hydroxide nanotubes for enhanced photocatalysis (2026) · doi

  The photocatalytic tests were performed at room temperature (25°C) for only 45 minutes; systematic investigation of temperature-dependent photocatalytic activity (40-80°C), extended reaction times beyond 45 min, and thermal stability of high-entropy (oxy)hydroxide nanotube catalysts under elevated photocatalytic conditions has not been addressed.

• Smart Electrochemical Sensors and IoT for Monitoring Heavy Metals in Nigerian Water: Review of Advances and Deployment Challenges (2026) · doi

  The paper discusses IoT platforms for water quality monitoring but does not address power constraints and solar energy harvesting specifications for autonomous electrochemical sensor networks in rural Nigerian communities with limited electricity infrastructure. Optimization of SEH-WSN (solar energy harvesting wireless sensor networks) specifically for heavy metal detection devices in off-grid locations requires design parameters and performance benchmarks.

• Một phương pháp tính toán quy đổi lưu lượng trục xe khai thác về trục xe tiêu chuẩn trong thiết kế mặt đường bê tông xi măng (2026) · doi

  The study focuses on specific concrete slab thicknesses (20-26 cm) and foundation stiffness ranges (60-80 cm); broader ranges and additional pavement configurations require investigation.

• Multifunctional PVC-based metal oxide/graphene composites for high-performance DSSC counter electrodes (2026) · doi

  While five independently fabricated devices were tested for each CE composition, the reproducibility and consistency of the PVC/ZnO/G composite across larger-scale manufacturing and different fabrication batches remain unexplored.

• Performance evaluation of the effect of tilt angle on a grid connected photovoltaic power plant using PVsyst (2026) · doi

  Exploring the economic and environmental impacts of adopting optimized solar PV systems across different regions would provide a broader perspective on their scalability and feasibility.

• Inverse-synthetic-aperture-radar imaging-driven customized polarization-programmable meta-illusions enabled by spin-multiplexed single-layer metasurfaces (2026) · doi

  Migration of the BLPS-ISAR illusion paradigm from metallic realizations to high-index all-dielectric metasurfaces to provide reduced absorption loss, improved power-handling capability, and CMOS process compatibility.

• Research Progress of Wearable Flexible Sensors (2026) · doi

  The field still faces challenges such as long-term stability, balance of sensitivity and detection range, signal crosstalk, large-scale manufacturing, and data security.

• Study on Heavy Oil Viscosity Reduction by Ultrasound and Parameter Optimization Based on COMSOL Simulation (2026) · doi

  The study reveals the potential of 20 kHz ultrasound through numerical simulation but there are still many challenges to push it to practical engineering application.

• Aerodynamic and Structural Enhancement Strategies for Modern Aircraft Fuselage Design (2026) · doi

  The paper lacks detailed analysis of manufacturing scalability and cost-effectiveness of Automated Fiber Placement (AFP) and advanced manufacturing technologies for large-scale aircraft production.

• Engineering Biology for Space Health: An Innovative Research Roadmap (2024) · doi

  Current NASA efforts to investigate utilization of lunar regolith through microwave power, pyrometer technologies, electrolysis, and other methods are still in very early stages and require further development.

• Dedicated and Reconfigurable Artificial Neurons and Synapses based on Two-Dimensional Materials for Efficient Neuromorphic Application (2026) · doi

  The physical switching mechanisms of functional materials are often constrained by their intrinsic kinetic processes, leading to undesirable operational delays.

• A Family of Symmetrical Integrated Synchronizations for Grid-Following and Grid-Forming Inverters (2026) · doi

  The paper does not discuss the scalability and applicability of the proposed methods to large-scale grid systems with multiple interconnected inverters or microgrids.

• Modular Battery Architecture for Off‑Highway Electric Machinery (2026) · doi

  Battery swapping ecosystems are not yet mature enough to be universally viable; more development of standardized swapping interfaces across different OEMs is needed.