Proven or predictable shortages of materials and the necessary frugality associated with the energy transition create a constrained framework for the sustainable deployment of microelectronics and microsystems technologies. This thesis is thus part of an approach that aims to significantly reduce the environmental footprint of piezoelectric MEMS actuator/sensor technology. The latter is based on the use of a functional lead-based material, PZT (Pb(Zr,Ti)O3), and requires electrode materials such as Pt, Ru, Au, and doping elements such as La, Mn, Nb which are used to optimize piezoelectric properties and electrical reliability. The thesis work will make it possible to identify technological obstacles and propose solutions to move towards a sustainable and reliable piezoelectric MEMS technology, based in particular on Life Cycle Analyzes (LCA) and reliability data (lifetime) from existing technology at LETI. Modeling will be used to optimize the properties of lead-free piezoelectric materials considered and more generally of the actuator/sensor stack (material by design approach). It will also be necessary to take into account both the materials and the deposition/integration processes to move towards the objective of reducing the environmental impact of piezoelectric MEMS technology while retaining material/device properties in the specifications for applications targeted.