Femtosecond laser-assisted etching: making arbitrary shaped 3D glass micro-structures

With fast development of interdisciplinary fields relying on various micro-and nano-structures (for instance, microfluidics, micromechanics or biomedicine) the pressure is on for the fabrication technologies to meet the ever increasing demands for the manufacturing throughput and applicable materials. Glass is one of the key substances used through the ages for creation of various objects, yet till this day the possibilities to process it in micro-scale in 3D fashion is limited. Here, we provide examples of structures that can be created out of glass by applying fs laser assisted selective etching. These include molds for micromechanical part creation, high-quality microchannels and microneedle arrays. The possibilities, limitations and perspectives of this microfabrication technology are discussed, comparisons with additive manufacturing are provided.