In this joint project, the applicants are pursuing a novel concept for a hybrid burner nozzle design to advance the vision of liquid ammonia combustion in stable spray-flames. The innovative design combines two mechanisms for atomization, i.e. pressurized and dispersion-gas atomization, to obtain efficient stable combustion with carbon-free fuels. The keys for the realization of this concept and for overcoming the associated scientific challenges are the subtractive manufacturing process ‘Selective Laser-induced Etching’ (SLE) and the fundamental understanding of atomization and flame processes for superheated liquefied ammonia. Only SLE is capable of producing the underlying complex three-dimensional flow topology with unsurpassed accuracy and defined surface roughness. At the same time, due to ist transparent design, it provides the basis for a first-time simultaneous nozzle-internal and nozzle-external experimental analysis of physical sub-processes involved. New insights achieved in this way will be incorporated into the development of high-fidelity models of the entire spray-flame process. In this context, flash-boiling is identified as the crucial process to be investigated and understood by taking into account the entire process chain inside and outside the nozzle.