Composite patch with negative Poisson's ratio mimicking cardiac mechanical properties: Design, experiment and simulation

• Published in: Materials today bio 2024-06, Vol.26, p.101098-101098, Article 101098
• Main Authors: Dong, Zhicheng, Ren, Xiaoyang, Jia, Ben, Zhang, Xuanjia, Wan, Xiaopeng, Wu, Yang, Huang, Heyuan
• Format: Article
• Language: English
• Subjects: Auxetic metamaterials; Biomimetic design; Cardiac composite patch; Finite element analysis; Full Length; Mechanical properties testing
• ISSN: 2590-0064; 2590-0064
• DOI: 10.1016/j.mtbio.2024.101098

Developing patches that effectively merge intrinsic deformation characteristics of cardiac with superior tunable mechanical properties remains a crucial biomedical pursuit. Currently used traditional block-shaped or mesh patches, typically incorporating a positive Poisson's ratio, often fall short of matching the deformation characteristics of cardiac tissue satisfactorily, thus often diminishing their repairing capability. By introducing auxeticity into the cardiac patches, this study is trying to present a beneficial approach to address these shortcomings of the traditional patches. The patches, featuring the auxetic effect, offer unparalleled conformity to the cardiac complex mechanical challenges. Initially, scaffolds demonstrating the auxetic effect were designed by merging chiral rotation and concave angle units, followed by integrating scaffolds with a composite hydrogel through thermally triggering, ensuring excellent biocompatibility closely mirroring heart tissue. Tensile tests revealed that auxetic patches possessed superior elasticity and strain capacity exceeding cardiac tissue's physiological activity. Notably, Model III showed an equivalent modulus ratio and Poisson's ratio closely toward cardiac tissue, underscoring its outstanding mechanical potential as cardiac patches. Cyclic tensile loading tests demonstrated that Model III withstood continuous heartbeats, showcasing outstanding cyclic loading and recovery capabilities. Numerical simulations further elucidated the deformation and failure mechanisms of these patches, leading to an exploration of influence on mechanical properties with alternative design parameters, which enabled the customization of mechanical strength and Poisson's ratio. Therefore, this research presents substantial potential for designing cardiac auxetic patches that can emulate the deformation properties of cardiac tissue and possess adjustable mechanical parameters. [Display omitted] •A functional hydrogel-integrated auxetic composite cardiac patch was designed and fabricated.•The auxetic composite patch demonstrated the Poisson's ratio range and equivalent modulus ratio more closely aligned with the deformation behavior of cardiac tissue.•The auxetic composite patch substantially enhanced the stress distribution compared to traditional structures, offering improved static and fatigue resistance properties.•Precision control over the modulus ratio and Poisson's ratio for the auxetic composite patch has been accompli