An important topic in the field of rocket propulsion is the development of a new green advanced hypergolic rocket propulsion system. The current hypergolic propellants have one large drawback, namely the toxic properties. The injector has a crucial role in the performance of a liquid engine. Therefore, the next step in the development of this novel propulsion system is the development of the injector. The purpose of this master thesis is to design, manufacture, and test this novel injector. The injector is designed to operate in monopropellant and bi-propellant modes, which is supported by the new green hypergolic propellants. In total, four different configurations of the injector are developed. Different testing objectives are defined for the experiments to test all the injector configurations. These testing objectives are atomization behavior, atomization performance, the mixing process in bi-propellant mode operation, and atomized flow in combination with the heating element.