Neurotechnology applies methods and devices to mitigate the burden of neurological and mental disorders. In particular, neural interfaces establish a long-term, seamless, symbiotic integration between implants and neural tissue. Materials play a pivotal role in neurotechnology. Advanced materials and materials engineering are crucial to achieving the desired function and outcome. Recently, neural interfaces extended their range of applications with the emergence of flexible, conformable, stretchable, injectable, and transient electronics. However, despite this enormous advancement in materials science and engineering, clinical devices still rely on old-fashioned but reliable materials and processes. The gap between research development and industry adoption has recently gained high interest. This article analyzes recent developments, discusses roadblocks, and provides a roadmap for materials engineering applied to neurotechnology.