The International Conference on Leading Edge Manufacturing in the 21st Century (LEM21) was established as a premier international forum for researchers and engineers to present and discuss the latest advances in manufacturing science and technology. LEM21 2025 was held in Okinawa, Japan in December 2025, bringing together experts from academia and industry to share cutting-edge research on precision engineering, advanced manufacturing processes, automation, and intelligent production systems.
In response to the rapid evolution of manufacturing technologies driven by digitalization, automation, and sustainability requirements, this special issue of the International Journal of Automation Technology aims to capture the most recent achievements and emerging trends presented at LEM21 2025 as well as related original contributions. This special issue focuses on the integration of leading-edge manufacturing processes with automation, robotics, sensing, and intelligent control, which are essential for next-generation production systems.
Extended and substantially revised versions of selected papers presented in LEM21 2025 are strongly encouraged. Original papers that align with the scope of this special issue and contribute to the advancement of automation technology in manufacturing are also welcome.
The topics of interest include, but are not limited to:
* Advanced machine tools
* Mechatronics- and robotics-integrated manufacturing
* Digital manufacturing (CAD, CAM)
* Smart manufacturing (IoT, AI, CPPS)
* Cutting technology
* Grinding technology
* Finishing technology
* Forming technology
* Electrophysical and chemical processes
* Laser processing
* Additive manufacturing
* Surface, tribology, and structuring technologies
* Nano/Micro measurement and intelligent instruments

This special issue aims to bring together the latest research and practical case studies on design and manufacturing for environmental sustainability, especially those that deal with a holistic view of technology, business, legislation, energy, resources, infrastructures, and customer behavior. Papers ranging from theory to application and case studies are welcome. Topics of interest in this special issue include, but are not limited to, the following:
* Design for sustainability and circularity: ecodesign, life cycle design, scenario design, product service system design, and design for XaaS, design for circularity, and design for X.
* Manufacturing aspects of sustainability: sustainable manufacturing, carbon neutralization in manufacturing, reduced energy and/or resource consumption, digital transformation in manufacturing, and sustainable value chain management
* Business and social aspects of sustainability: SDGs, circular economy, ecobusiness planning, product service system business, sharing business, and environmental legislation
* Information platform for enhancing circular economy and/or environmental sustainability
* Planning and design of sustainable infrastructure systems: “smart” cities, zero energy buildings, circular economy platforms, and designing circular economy ecosystems
* Scenario planning and/or analysis for sustainability
* Energy management and new energy technologies

Additive manufacturing (AM) has matured rapidly over the past decade and is recognized as one of the most promising techniques for producing parts with complex and functional geometries that are difficult to manufacture using conventional subtractive processes. Various materials, such as polymers, metals, ceramics, and graphite can be used to produce end products. Each AM method has distinct characteristics, such as the type and form of feedstock, the precision achievable, and the required post-processing. Most AM processes repeatedly melt and solidify material using a heat source to build three-dimensional parts. However, AM involves many interacting parameters, including heat sources and environmental factors. Although these are the main factors affecting product quality, their coupled effects make it difficult to fully understand the phenomena that occur during AM.

This special issue focuses on recent trends in AM to advance the chatter-free depth of AM technologies. Submissions should demonstrate a deep understanding of AM processes and their enhancement to improve the mechanical properties and dimensional accuracies of built parts. We are also welcome reports of successful industrial applications with optimized configurations, hybrid processes, material reuse, post processes, and material developments applied to AM techniques.

Recent advances in 3D scanning and reconstruction technologies based on LiDAR and digital images enable flexible acquisition of geometric and appearance information from physical objects and environments. These technologies are currently essential for engineering product development and the maintenance of plants, factories, infrastructure, forests, and urban environments. In addition, reliable and efficient technologies for 3D acquisition, processing, recognition, modeling, and application of digital geometry data are becoming increasingly important for cyber-physical systems. The main objective of this special issue is to present the latest research results on digitized geometry processing using 3D scanning and reconstruction, as well as its applications across various fields. Related topics include, but are not limited to, the following:

• 3D scanning, reconstruction, and sensing technology, and systems for 3D geometry data
acquisition,
• Data processing algorithms, principles, and theory for the acquisition of 3D geometry data,
• Recognition and modeling from acquired 3D geometry data for objects and environments,
• Application of acquired 3D geometry data to automation and simulation technology.

The papers in this special issue present the latest advances in the application of 3D scanning and reconstruction technology. The sharing of these advances will help readers better explore and understand the technologies.

Always welcome