Microfabrication by two-photon lithography, and characterization, of SiO2/TiO2 based hybrid and ceramic microstructures

Abstract

High resolution fabrication using two-photon lithography is extensively studied for a large range of materials, from polymer to inorganics. Hybrid materials including a sol–gel step have been developed since two decades to increase mechanical or optical properties in particular on silicon-based materials. Among the metal oxide, few studies have been dedicated to titanium and, because of the high reactivity of titanium precursors, obtaining a resin with a high part of titanium is challenging. Indeed, resins for two-photon lithography have to be stable for the processing time and titanium precursors are more difficult to operate due to their higher reactivity and often require extreme working conditions in order to control the chemical processes. Here, we propose a method, working at ambient conditions, to print submicronic structures of organic–inorganic hybrids with a large proportion of titanium and ceramics using high resolution two-photon process. The material obtained and its evolution during the pyrolysis at 600 and 1000 °C are characterized. We show that TiO2/SiO2-based microceramics can be obtained after the pyrolysis of the microstructures. The respective roles of the two chemical reactions involved in this lithography process, sol–gel condensation and radical photopolymerization, are highlighted.