Fig. 3From: Polyetheretherketone implants with hierarchical porous structure for boosted osseointegrationCharacterization of surface properties. A Surface roughness of different samples (n = 4). B FTIR spectra of various sample surfaces. C Contact angles of water and diiodomethane on different sample surfaces (n = 6). D Total surface energy calculated by the Owens two-liquid method using the data of contact angle (n = 6). E Compressive stress–strain curves of different samples. F Compression moduli of different samples (n = 3)Back to article page