Biomedical Engineering Reference
In-Depth Information
only on the hydrophilic pedestals' top forming separated regions. Shiu et al. [
210
]
have reported nanostructured switchable superhydrophobic surfaces allowing fast
and addressable protein deposition. The wettability of the superhydrophobic surface
was controlled by electrowetting, which converted a water-repellent superhy-
drophobic surface into a wettable one. A novel multicomponent protein-patterning
technique has also been integrated on these switchable superhydrophobic surfaces
and 100
100 protein spots with 10
m resolution can be created within one
second. In addition, much effort has been endeavored to improve the cell adhesion,
transfection efficiency, and colony separation in cell microarrays application. Shiu
et al. [
211
] have found that cells attached preferentially on the roughened area of
patterned superhydrophobic surfaces allowing the formation of cell microarrays.
The great improvement of transfection efficiencies of the CHO cells and NIH 3T3
cells was observed on the superhydrophobic surfaces. The author concluded that
the patterned superhydrophobic surfaces could be used as cell microarrays with the
advantages of enhanced cell adhesion natural separation of colonies and improved
transfection efficiency.
Platelet adhesion and activation on material surfaces may cause blood coagula-
tion and thrombosis, which impede the function of artificial manmade blood vessels,
organ implantations, and other blood-contacting medical devices. Therefore, it is
desired to fabricate more blood-compatible materials. Due to the anti-cell adsorption
properties of superhydrophobic surfaces, they may find potential application in
clinical therapy and biomedical research. Sun et al. [
212
] have examined platelet
adherence property on partly fluorinated poly(carbonate urethane) (PCU) super-
hydrophobic surface compared with a flat PCU surface. The results showed that
significant platelet adherence is observed on the flat PCU surface and almost
no adhered platelet found on the superhydrophobic one. The flow cytometry
analysis and immunofluorescence experiments were also executed on these surfaces,
indicating their good biocompatibility.
9.5.10
From Microdevices to Marina Industry
Superhydrophobic coatings have excellent water repellency, and they may find
applications electronic devices coating and marina technology. Samuel et al. [
213
]
have reported that the waterproof coating can be securing some moisture-sensitive
electronic devices. In his report, thin fluoropolymer superhydrophobic coatings were
applied on the surfaces of field effect transistor devices via violet photochemical
process. It has been found that even at high relative humidity the superhydropho-
bic coating can eliminate the surface discharge caused by the leakage current.
Microwave telecommunication antennae also utilize superhydrophobic coating to
reduce water and ice accumulation on its surface, because they can impede the
telecommunication and weaken the signals. In the Yamauchi et al. study [
214
],
PTFE was coated on the surfaces of microwave antennae as an ice-proof layer.
The authors have found effective prevention of snow or ice accumulation on the
