Implantable medical devices to interface with muscles, peripheral nerves, and the brain have been developed for
many applications over the last decades. They have been applied in fundamental neuroscientific studies as well
as in diagnosis, therapy and rehabilitation in clinical practice. Success stories of these implants have been
written with help of precision mechanics manufacturing techniques. Latest cutting edge research approaches to
restore vision in blind persons and to develop an interface with the human brain as motor control interface,
however, need more complex systems and larger scales of integration and higher degrees of miniaturization.
Microsystems engineering offers adequate tools, methods, and materials but so far, no MEMS based active
medical device has been transferred into clinical practice. Silicone rubber, polyimide, parylene as flexible
materials and silicon and alumina (aluminum dioxide ceramics) as substrates and insulation or packaging
materials, respectively, and precious metals as electrodes have to be combined to systems that do not harm the
biological target structure and have to work reliably in a wet environment with ions and proteins. Here, different
design, manufacturing and packaging paradigms will be presented and strengths and drawbacks will be
discussed in close relation to the envisioned biological and medical applications.