The concept of replaceable micro cavities can be applied in the design of moulds for different applications and the efficiency of the product development stage is greatly improved. The inserts allow easy testing of the design prototypes especially in highly interdisciplinary fields where manufacturing challenges such as replication, structuring of moulds, polymers, sealing, integration of functional elements, and the production of (customised) disposables at competitive prices all still need to be addressed. In this direction laser micromachining technology meets the need for fabricating micro-injection mould inserts with complex shapes and a high level of accuracy.