Photostructurable polymers, such as SU-8, have large potential impact on the field of MEMS/NEMS, allowing simple fabrication of plastic MEMS/NEMS devices with nearly vertical sidewalls and high aspect ratios using standard photolithographic procedures. Functional properties (as electrical conductivity or photoluminiscence) can be added to a photostructurable polymer by doping the material with nanoparticles and/or nanocrystals. We present here the case in which the resulting material presents opto-thermal properties if it is combined with an undoped polymer. From all the different mechanisms for heating the structure, opto-thermal actuation is interesting from the point of view that it is possible to obtain a mechanical energy transduction without requiring physical contact or proximity interaction, i.e. devices can be moved merely by focusing light on it.