Mechanical behavior control in cranial implant cells via structural optimization: a path to sensitivity management

Purpose This study explores the mechanical behavior of cranial implant unit cells designed to offer tunable compliance characteristics while maintaining constant mass and geometric constraints. The goal is to demonstrate that postoperative cranial sensitivity can be addressed by locally adjusting the stiffness of implantable structures at the cellular level. Design/methodology/approach Two distinct implant unit cell configurations were developed using a deformation-driven optimization approach. Although their geometry and mass were identical, internal stiffness distributions were altered by changing cross-sectional design bounds in the optimization algorithm. Experimental validation was carried out through compressive loading tests, and force–displacement data were analyzed to assess the mechanical response of each design. Findings The results showed that it is possible to significantly alter the elastic behavior of unit cells by adjusting internal architecture without changing overall volume or material. The M2 model, in particular, exhibited a broader low-stiffness plateau in its force–displacement curve, suggesting enhanced suitability for sensitive cranial zones. The degree and spatial extent of compliance could be effectively controlled through simple modifications of optimization parameters. Originality/value Unlike conventional cranial implant studies that focus on full-implant geometry, this work introduces a scalable, unit-cell-based approach where local mechanical performance can be tuned through structural optimization. The methodology supports the integration of sensitivity-specific zones within future implant assemblies using pre-validated, stiffness-controlled cellular modules.