Biomedical Engineering Reference
In-Depth Information
Figure 31.13.
Drop-on-demand 3DP system: (a) diagram of DDP system
components and (b) digital photograph of inkjet print heads in this DDP
system, Solidscape Modelmaker II. See also Color Insert.
Xu
et al.
usedacommercialthermalprinter,whichwascomposed
ofanHPdesktopprinter(HP550C)andanHP51626ainkcartridge,
to deposit Chinese hamster ovary (CHO) cells and hydrogel-based
materialsfortissueengineering.
42
AnalysesoftheCHOcellsshowed
that more than 90% of cells were not damaged during nozzle dis-
pensing.AcompleteringofCHOcellswasobservedonsoyagarbio-
paperafterday7.Thecellscontinuedtoproliferateuntilacomplete
circle was formed by day 25. Therefore, cell-printing technologies
basedontheinkjetprinterwillofferresearchersacost-effectivetool
to rapidly fabricate cell patterns and tissuelikestructures.
31.2.4
Selective Laser Sintering
SLS is a technology that uses a CO
2
laser beam to sinter thin layers
of polymer, ceramic, or composite (polymer/ceramic/multiphase
metal) powders, thus forming solid 3D objects. During the SLS
process, the laser beam is scanned selectively over the surface of a
powder bed, following the cross-sectional profiles of the slice data
generated by the computer program. The irradiation of the laser
beam raises the powder temperature at the irradiation point, and
sintering occurs just beyond the glass transition temperature, caus-
ing the particles to fuse together to form a solid structure. The solid
structure sinks to bottom of the powder, and new layers of powder
are deposited by a roller.
43
Next, layers are fabricated directly on
top of the previously sintered layers. During fabrication, the struc-
ture is supported and embedded by the surrounding unprocessed
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