Recently, polylactide (PLA) ultrathin films were developed for biomedical applications as wound dressings and a part of tissue engineering constructs. Owing to many excellent properties such as sufficient flexibility, biodegradability, adhesiveness, and transparency, the films displayed an efficient ability to prevent bacterial penetration into the wound. In this work, silver nanoparticles (SNPs) with the particle size of 2–3 nm were used as an antibacterial agent. The homogeneous ultrathin films of SNP/PLA nanocomposite were prepared with a thickness of 100–700 nm and the concentration of SNPs up to 10 wt%. The films exhibited strong antibacterial activity against S. aureus, E. coli and B. subtilis. Although the addition of a large amount of SNPs into the neat PLA leads to decreases in tensile strength, elongation at fracture and Young’s modulus, the SNP/PLA ultrathin films could be potentially used as an antimicrobial wound dressing for tissue regeneration.

Multifunctional 3D-printed holey structures made of composite polymers loaded with nanocarbon were designed to serve simultaneously as GHz-radiation absorbing layers and heat conductors. The geometry of the structures was devised to allow heat to be easily transferred through, with special attention paid to thermal conductivity. Numerical calculations and a simple homogenization theory were conducted in parallel to address this property. Different structures have been considered and compared. The electromagnetic shielding effectiveness of the produced holey structures was measured in the microwave range.

Auxetic structures have garnered considerable interest for being lightweight and exhibiting superior properties such as an excellent energy absorption capability. In this paper, re-entrant and missing rib square grid auxetic structures were additively manufactured via the fused deposition modeling technique using two types of polyether imide materials: ULTEM 9085 and ULTEM 1010. In-plane quasi-static compressive tests were carried out on the proposed structures at different relative densities to investigate the Poisson’s ratio, equivalent modulus, deformation behavior, and energy absorption performance. Finite element simulations of the compression process were conducted, which confirmed the deformation behavior observed in the experiments. It was found that the Poisson’s ratio and normalized equivalent Young’s modulus of ULTEM 9085 and ULTEM 1010 with the same geometries were very close, while the energy absorption of the ductile ULTEM 9085 was significantly higher than that of the brittle ULTEM 1010 structures. Furthermore, a linear correlation exists between the relative density and specific energy absorption of missing rib square grid structures within the investigated relative density range, whereas the relationship for re-entrant structures follows a power law. This study provides a better understanding of how material properties influence the deformation behavior and energy absorption characteristics of auxetic structures.