One way to solve this conundrum is to use ultra-fast local radiant heating with an infrared emitter or laser. The principle here is the ultrafast energy transfer to the coating, prompting the annealing to stabilize it while minimizing the heat transmitted to the polymer and electronic parts underneath. The technique has successfully been applied for the fabrication of thin oxide films on heat-sensitive polymers. It is also applicable to photoactive TiO2 films, Robertson et al. used it on TiO2 and could show that strong laser intensity promoted conversion into rutile and formation of Ti(III). However, there is no information about whether this actually improves the mechanical stability of the coatings akin to conventional thermal annealing. Also, the technique has hitherto only been applied to planar substrates, whereas complex geometries present an additional challenge.