In the last years, the huge proliferation of portable devices with increasing energy demands requires new technologies with higher power and storage density than batteries. Micro solid oxide fuel cells (micro-SOFCs) present the highest value of specific energy density and they allow a direct operation with hydrocarbons. The Ultra-SOFC project, managed by IREC (Catalunya Institute of Energy Research), is developing functional free-standing membranes integrated in silicon-based micro fabricated substrates. This thesis is carried out in the framework of the Ultra-SOFC project and it aims to develop innovative solutions in micro-SOFC state of art to increase reliability. Two main topics have been considered: (1) the optimization of the joining thermal treatment and characterization of a commercial glass-based sealant (carried out mainly at POLITO) and (2) a new ceramic anode deposited as a thin film (carried out at IREC).