Robotic exhalation is a novel digital fabrication methodology that uses digitally controlled pulses of compressed air to form concrete panels that can vary in porosity and surface morphology. In the robotic exhalation workflow, a pen plotter-turned-exhalation machine continually blows compressed air onto concrete immediately after it has been poured into an open face mold. The constant air flow repeatedly forms the wet concrete until the mixture sets. The designer specifies where the machine exhales, for what duration, and with what force, as well as the rheology of the concrete.