In this chapter, different concepts of microtechnical interfaces to neurons are introduced. A description of hand-crafted neural devices is given which demonstrates the principle applications, limitations and needs of advanced interfaces. The postulation for advanced neural interfaces leading to the discussion on utilizing microelectromechanical systems for neural prostheses. Two on-going research projects are presented highlighting the technical possibilities for the design of neural interfaces. The first example describes a neural prosthesis for an amputee model to control an artificial limb. Secondly, concepts and realization steps are given for a sensory prosthesis which will aid people suffering from a special kind of blindness. A discussion on future concepts follows that outlines possible directions of research and development with the aim of clinical use, implantability of the whole system, wireless signal and energy transmission and closed-loop control of and with biological systems. Possible applications not only include restorative and rehabilitation purposes but also therapeutic applications for pain relief or bio-artificial drug delivery.