Complete shape retention in the transformation of silica to polymer micro-objects.

Controlled morphogenesis and shape replication are challenges for several rapidly developing fields of materials science. Indeed, although complex forms have been generated by the condensation of inorganic matter in organized media, the shaping of plastic matter on the micrometre scale is still limited to simple forms that are typically obtained as inverse replicas of channel-like cavities and colloidal crystals. Here we report the fabrication of individual plastic micro-objects that follow an elaborate design and are faithful copies of nanoporous inorganic morphotypes. The direct replica method produces an unprecedented library of curved geometrical solids made of plastics, such as cones, bicones, hollow cylinders, rings, test tubes, clubs and vases. The shape retention of the original structures on the microscale and the creation of a new nanostructure produced objects with homogeneous nanopores of 7 nm and cylindrical microcavities as large as 1 microm. This strategy of shape transcription from one material to another opens new perspectives in microfabrication, separation, anchorage and storage of chemical and biological species. Until now it has not been possible to realize such transformations.