Strut-based lattice metamaterials with near-zero Poisson’s ratio for bone tissue engineering applications

Strut-based lattice metamaterials exhibiting near-zero Poisson’s ratio (NZPR) behaviour have been identified as potential candidates for orthopaedic implants because of their limited lateral expansion and dimensional stability. This study presents a systematic, comparative evaluation of three previously reported honeycomb-based NZPR lattices, namely RSRE, P-ZPR, and SRE-1, and two novel honeycomb-based NZPR lattices, namely SRE-2 and SRE-3, relative to conventional body-centred cubic and face-centred cubic reference lattices, which exhibit positive Poisson’s ratios (PPR). The evaluation is performed within the context of bone tissue engineering, using load-bearing lumbar interbody fusion (LIF) as an exemplary application. Compressive behaviour, deformation mechanisms, Poisson’s ratio evolution, von Mises stress distribution, energy absorption, and morphological parameters were characterised through experimental investigations and finite element simulations. All NZPR lattices exhibited bending-dominated deformation with near-zero lateral strain, whereas SRE-type lattices displayed comparatively more homogeneous stress distributions than the other NZPR and PPR configurations. The P-ZPR lattice demonstrated superior compressive strength and energy absorption capacity, while RSRE and SRE-3 exhibited highly compliant mechanical responses with stable progressive collapse, though insufficient load-bearing capacity for use in primary structural components. Among the designs investigated, SRE-2 was the most promising for load-bearing LIF implants, offering an effective compromise between material consumption and mechanical performance, combined with controlled collapse behaviour and favourable morphological characteristics. The findings highlight the substantial potential of NZPR lattices to advance the development of biomaterials for bone tissue engineering applications. Further, a qualitative basis for the initial rational selection of NZPR lattice configuration for bone tissue engineering applications was established.