In response to the complex healthcare needs posed by global population aging, a new review in
International Journal of Extreme Manufacturing offers a comprehensive overview of how additive manufacturing (AM) and mechanical metamaterials together contribute to more precise, efficient, and personalized biomedical applications, particularly in the design and manufacture of advanced implants and tissue constructs.
Biomaterials have long been essential in helping patients recover function and quality of life following disease or injury, and mechanical metamaterials—engineered structures with properties defined by internal architecture rather than composition—have garnered increasing attention for their ability to mimic complex biological functions. Combined with AM, these materials enable new frontiers in personalized, precise, and adaptable healthcare solutions.
The review systematically categorizes recent developments in the materials used for AM and the functional classification of mechanical metamaterials, including those inspired by natural systems such as plant stems or animal exoskeletons. This biomimicry provides novel solutions for integration with human tissue, offering enhanced functionality and biological performance.
“In particular, we’ve seen major strides in biomimetic mechanical metamaterials—structures designed to imitate natural biological mechanics—which are now being explored for applications ranging from orthopedic implants to tissue scaffolds,” said first author Junsheng Chen.
Despite advances in structural design, printing functional living tissues remains a major challenge. Current technologies struggle to replicate the complexity of biological environments, where precise placement of matrix components, growth factors, and vascular structures is critical. Limited printing speed and resolution, along with the diversity of cell types and bioactive substances, further constrain the creation of large, detailed, and physiologically relevant tissue models.
To address these varied needs, a range of AM technologies has emerged, each suited to different material and functional requirements. The review highlights several key approaches: extrusion-based bioprinting for cell-laden structures; powder bed fusion (PBF-LB/M) for high-strength metallic implants; stereolithography and digital light processing for high-resolution tissues; and continuous liquid interface production for scalable bioprinting. Each has distinct advantages, yet none are without trade-offs—particularly in balancing mechanical precision with biological compatibility.
On the materials front, ceramics continue to lead in bone and dental applications due to their strength and biocompatibility, although further work is needed to improve their processability. Titanium and cobalt-chromium alloys remain staples for load-bearing implants, while biodegradable magnesium alloys offer exciting prospects for temporary support structures. Polymers, prized for their flexibility and ease of processing, are now widely adopted for prototyping and functional tissue models.
Looking forward, the commercialization of AM-based metamaterials will depend not only on technical refinement but also on overcoming regulatory and standardization bottlenecks. “
One of the major non-technical hurdles is that regulatory frameworks often lag behind technological advances,” Prof. Jibing Chen noted. “If we can address this challenge, the widespread clinical adoption of AM-based metamaterials may become a reality sooner than expected.”
With aging societies driving demand for more personalized and regenerative healthcare solutions, this review positions additive manufacturing and mechanical metamaterials as key enablers of next-generation biomedical technologies.
DOI 10.1088/2631-7990/ad88e3
About IJEM:
International Journal of Extreme Manufacturing (IF: 16.1, consecutive 1st in the Engineering, Manufacturing category) is a multidisciplinary and double-anonymous peer-reviewed journal uniquely publishing original articles and reviews of the highest quality and impact in the areas related to extreme manufacturing, ranging from fundamentals to process, measurement, and systems, as well as materials, structures, and devices with extreme functionalities.
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