A multi-photon reactive composition comprises an ethylenically unsaturated liquid polysilazane precursor, a multi-functional thiol additive, a multi-ethylenically-unsaturated additive different from the polysilazane, and a multi-photon photocuring composition. The invention can be used to provide ceramic-based microstructures as, for example, high temperature resistant materials, including devices such as microcombustors, micro-heat-exchangers, sensor and actuator systems, microfluidic devices, and micro-optics systems that can be used independently or integrated into other systems.