Biomedical Engineering Reference
In-Depth Information
Fig. 12.11
Micro-/nano-fl uidic channels by means of 3D laser lithography. Courtesy of Nanoscribe
GmbH (
www.nanoscribe.de
)
higher) and no chemical attacks are needed, thus leading to fi nal devices “cleaner”
for bio-applications and with much more homogeneous surfaces and features. In
addition this process is almost completely automated, while more conventional
micro-manufacturing processes require several steps and extremely well-trained
laboratory craftsmen.
Perhaps a limiting factor for some applications is the impossibility of directly
processing metals through direct laser writing. However, it is important to note that
organic photoresists (like SU-8, IP-L, IP-G), hybrid materials (ormocere) or the
amorphous semiconductor As
2
S
3
are capable of two-photon polymerization, what
provides a wide range of possibilities. In addition to CVD/PVD coating processes
(see Chap.
13
)
, fi nal metallization is possible and casting processes can also be used
for additional versatility.
The prototypes from Fig.
12.12
show cell scaffolds made of ormocere. The white
photographs are SEM images and the black/green ones are 3D reconstructions of
LSM confocal image stacks. Mammalian cells were cultured and the images show
how scaffold orients their movements. Images courtesy of Klein, F.; Striebel, T.;
Jiang, Z.; Franz, C.M.; Von Freymann, G.; Bastmeyer, M.; Karlsruhe Institute of
Technology (KIT) (Klein et al.
2010
).
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