Evaluation of MEMS materials of construction for implantable medical devices

Medical de, ices based on microelectro-mechanical systems (MEMS) platforms are currently being proposed for a wide variety of implantable applications. However, biocompatibility data for typical MEMS materials of construction and processing. obtained front standard tests currently recognized by regulatory agencies, has not been published. Likewise, the effects of common sterilization techniques on MEMS material properties hake not been reported. Medical device regutatory requirements dictate that materials that Lire biocompatibility, tested be processed and sterilized in a manner equivalent to the final production device. Material, processing. and sterilization method can impact the final result. Six candidate materials for implantable MEMS devices, and one encapsulating material, were fabricated using typical MEMS processing techniques and sterilized. All seven materials were evaluated using a baseline battery of ISO 10993 physicochemical and biocompatibility tests. In addition. samples of these materials,here evaluated using a scanning electron microscope (SEM) pre- and post-sterilization. While not addressing all facets of ISO 10993 testing, the biocompatibility, and SEM data indicate rev, concerns about use of these materials in implant applications. (C) 2002 Elsevier Science Ltd. All rights reserved.