The availability of SOI from silicon foundries is making implantable electrode array [3], all recognizing the benefits of SOI a viable option for implantable electronics devices. The field reduced power. has some specific needs that are different to many conventional electronics applications. Low power operation is essential but with II. VARIETIES OF SOI intermittent high power requirements and the need for long term reliability. Conversely, circuit operating speed requirements are . . often extremely low; including monitoring at only a few KHz. Data 501 an beplteinto toectrical types: partially depleted storage (memory) requirements may also be relatively low.(PD) and fully depleted (FD) and two basic physical types: Furthermore, the operating temperature range of implanted planar and non-planar. Both types can be constructed in both devices is low compared to many non-implantable applications.