310
S. Kirihara
Fig. 10.7 Transmission attenuation of terahertz waves for the metallodielectric photonic crystal
with diamond lattice structure
10.5 Full Ceramic Components
Natural human bones have compact and cancellous structures to realize effective
compatibilities for physical activities and biological metabolism. The inner porous
structures show graded distributions from 50 to 90% in volume fractions, which
are mimicked in the fabrication of artificial bones. Conventional artificial bones
have homogeneous cancellous patterns of 75% porosity [11, 12]. By using the laser
scanning stereolithography, the hydroxyapatite artificial bones with the graded lattice
patterns were fabricated to realize effective biocompatibility and high mechanical
strength [13].
The graphic model of the graded porous structure was designed, as shown in
Fig. 10.8. The solid rods are connected regularly to create a tetra-pot structure of fourcoordinate lattices [14]. Because relationship between the scaffold porosities and rod
aspect ratios shows a simple proportionality, by changing the aspect ratio from 1.2
to 2.0, the structural porosity can be controlled from 53 to 80% comparing with
the natural bone. The fluid flow properties in the scaffold structure were simulated
using the computer fluid dynamic method, as shown in Fig. 10.9. The streamline
distribution of the biological fluid shows omni-azimuth propagation.
The resin components with bioceramic dispersions were fabricated successfully
by computer-aided design, manufacture, and evaluation. Photosensitive acrylic resin
with hydroxyapatite particles of diameter 10 µm at 45 vol. % was used as the ink
material in the printing process. Paste layers of 30 µm thickness were laminated, and
the composite lattices were created precisely in the micrometer order. In addition,
the part accuracies of the lattices were measured under a 25 µm size difference.
Fig. 10.8 Four-coordination
lattice model designed to
realize graded porosities as
an artificial bone of
biological scaffold
S. Kirihara
Fig. 10.7 Transmission attenuation of terahertz waves for the metallodielectric photonic crystal
with diamond lattice structure
10.5 Full Ceramic Components
Natural human bones have compact and cancellous structures to realize effective
compatibilities for physical activities and biological metabolism. The inner porous
structures show graded distributions from 50 to 90% in volume fractions, which
are mimicked in the fabrication of artificial bones. Conventional artificial bones
have homogeneous cancellous patterns of 75% porosity [11, 12]. By using the laser
scanning stereolithography, the hydroxyapatite artificial bones with the graded lattice
patterns were fabricated to realize effective biocompatibility and high mechanical
strength [13].
The graphic model of the graded porous structure was designed, as shown in
Fig. 10.8. The solid rods are connected regularly to create a tetra-pot structure of fourcoordinate lattices [14]. Because relationship between the scaffold porosities and rod
aspect ratios shows a simple proportionality, by changing the aspect ratio from 1.2
to 2.0, the structural porosity can be controlled from 53 to 80% comparing with
the natural bone. The fluid flow properties in the scaffold structure were simulated
using the computer fluid dynamic method, as shown in Fig. 10.9. The streamline
distribution of the biological fluid shows omni-azimuth propagation.
The resin components with bioceramic dispersions were fabricated successfully
by computer-aided design, manufacture, and evaluation. Photosensitive acrylic resin
with hydroxyapatite particles of diameter 10 µm at 45 vol. % was used as the ink
material in the printing process. Paste layers of 30 µm thickness were laminated, and
the composite lattices were created precisely in the micrometer order. In addition,
the part accuracies of the lattices were measured under a 25 µm size difference.
Fig. 10.8 Four-coordination
lattice model designed to
realize graded porosities as
an artificial bone of
biological scaffold