Free-standing nanorod arrays of a thermally cross-linked semiconducting triphenylamine were fabricated on conductive ITO/glass substrates via an anodic aluminum oxide (AAO) template-assisted approach. By using a solution wetting method combined with a subsequent thermal imprinting step to fill the nanoporous structure of the template with a cross-linkable triphenylamine derivative, a polymeric replication of the AAO was obtained after thermal curing and selective removal of the template. To obtain well-aligned and free-standing nanorod arrays, aggregation and collapse of the nanorods were prevented by optimizing their aspect ratio and applying a freeze-drying technique to remove the aqueous medium after the etching step. Because of their electrochemical properties and their resistance against organic solvents after curing, these high density nanorod arrays have potential application in organic photovoltaics.

The review highlights different approaches to template organic materials as well as hybrid materials that find or are expected to find application in optoelectronic devices. The first templating approach focuses on the use of preformed nanoporous membranes as templates for organic materials and polymeric materials. Such nanoporous templates can be track-etched membranes, anodic aluminum oxide membranes and other variants thereof, or block copolymer templates. Further, opals have been described as templates. In the second part, we have summarized developments that take advantage of self-assembly processes to pattern hybrid materials. Examples are sol-gel templating techniques using amphiphiles, evaporation-induced self-assembly, lyotropic templating as well as templating from block copolymers. Both routes are very promising templating approaches for optoelectronic materials and represent complementary rather than competing techniques.

Microelectromechanical systems (MEMS) have recently found strong interest in academia and industry. They result from the integration of mechanical elements, sensors, actuators, and electronics onto a silicon substrate. [ 1 ] The miniaturization of integrated systems offers the advantage of high effi ciency at low fabrication costs and novel functionalities. This emerging technology has led to a strong demand for micro-and nanometerscaled actuators. [ 2 ] Liquid-crystalline elastomers (LCEs) [3][4][5][6] are a class of functional materials that have been used for the fabrication of actuators for many years. Consisting of weakly crosslinked polymer chains that are covalently linked to stiff, shape-anisotropic molecules (mesogens), they combine the ability of self-organization from liquid crystals with the entropy elasticity of elastomers. Depending on the ambient conditions, these mesogens can either be in an unordered state (isotropic phase) or self-organized into ordered liquidcrystalline phases. In the isotropic phase, the polymer chains can adopt the entropically favored random-coil conformation. On the other hand, if the mesogens align into a liquid-crystalline phase, the polymer chains have to respond to the resulting anisotropic environment and adapt an anisotropic conformation. A phase transition between the liquid-crystalline and isotropic phases thus allows switching of the polymer backbone between these two conformations. This conformational change comes along with a macroscopic change of the sample's dimensions, [ 7 ] which enables the utilization of LCEs as materials for actuator applications. [ 6 , 8 , 9 ] Every stimulus that leads to a phase transition in the liquid-crystalline material (heat, UV light, presence of a solvent) can be used to trigger the actuation process. As a result of the reversibility of liquid-crystalline phase transitions, the change in shape is reversible as well. It has to be mentioned that these shape-changing effects can only be