Template wetting


Ordered nanofiber and microfiber arrays by lift-off


The release of one-dimensional nanostructures and microstructures fabricated inside porous templates is often accomplished by wet-chemical etching of the templates with acids or bases. The destruction of the molds is a severe drawback for the up-scaling of template-based approaches, particularly if ordered porous materials are employed. Therefore, we are investigating the mechanical removal of nanofibers and microfibers from the pores by a lift-off process without destroying the porous host. The lift-off process is facilitated be reducing the adhesion between the fibers inside the pores and the pore walls. To this end, the pore walls were modified, for example, by silanization. Highly ordered arrays of released nanofibers and microfibers are thus accessible. For example, Fig. 1 shows an ensemble of released mesoporous microrods. Mechanical lift-off also yields extended, highly ordered arrays of polymer microrods (Fig. 2). The templates remain intact and can be recycled.


Figure 1. Mesoporous silica microrod array obtained by mechanical release from a recyclable porous template.


Figure 2. Polymer microrod array consisting of poly(vinylidene difluoride) microrods obtained by mechanical release from a recyclable porous template.

back  |  print  |  to top