Study of the compression behavior of functionally graded lattice for customized cranial remodeling orthosis

Area of Science:

• Biomaterials Engineering
• Medical Device Design
• Computational Mechanics

Background:

• Deformational plagiocephaly requires treatment with cranial remodeling orthoses (CROs).
• Current CROs face challenges in adapting to infant head growth, leading to complications like pressure sores and suboptimal clinical results.
• There is a need for advanced materials that can provide customized support and adapt to continuous growth within CROs.

Purpose of the Study:

• To investigate the compressive behavior of a functionally graded lattice as a potential inner lining for CROs.
• To explore the design and mechanical properties of lattices with varying unit cell sizes and truss diameters.
• To develop and validate a numerical model for predicting lattice behavior under compression.

Main Methods:

• Experimental and numerical analysis of body-centered cubic (BCC) lattices with homogenous and graded properties.
• Systematic variation of unit cell size and truss diameter in lattice structures.
• Measurement of bulk material mechanical properties.
• Development of numerical simulations to predict compressive behavior.
• Comparison of numerical predictions with experimental compression data.

Main Results:

• Numerical simulations accurately predicted experimental results for both homogenous and graded lattices.
• Compression displacements in the graded lattice were proportional to local density, aligning with numerical models.
• Truss diameter variation offered a wider range of compressive responses compared to unit cell size variation, with minimal impact on overall geometry.
• Functionally graded lattices demonstrated tunable mechanical properties suitable for adaptive support.

Conclusions:

• Functionally graded lattices show significant potential as adaptive inner linings for cranial remodeling orthoses.
• Truss diameter variation is a more effective parameter than unit cell size for tailoring lattice mechanical response in this application.
• The developed numerical models provide a reliable tool for designing customized lattice structures for CROs, aiming to improve patient outcomes.