Polymers implanted medical electronic

The protection of microelectronics from the effects of humidity and corrosive environments presents especially demanding requirements on protective coatings and encapsulants. Silicone polymers, epoxies, and imide resins are among the materials that have been used for the encapsulation of microelectronics. The physiological environment to which implanted medical electronic devices are exposed poses an especially challenging protection problem. In this volume, Troyk et al. outline the demands placed on such systems in medical applications, and discuss the properties of a variety of silicone-based encapsulants. 

Humidity Testing of Silicone Polymers for Corrosion Control of Implanted Medical Electronic Prostheses... 

Polymer materials have been established as excellent materials in chemistry, automotives and electronics to interconnect different components, to electrically insulate conductors and to survive harsh corrosive environments. Polyimides are the most common material class for substrate and insulation materials in combination with metals for interconnection wires and electrode sites. Therefore, it is quite natural that the medical device industry has focused its attention to polyimides for medical devices in general and especially for encapsulation and insulation of active implants. Neural implants are technical systems that are mainly used to stimulate parts and structures of the nervous system with the aid of implanted electrical circuitry or record the electrical activity of nerve cells. Their application... 

The sterihsation of implantable devices is a subject of great concern for the medical industry. Since ionising radiation is preferentially used for this purpose, attention must be paid to possible effects on the structural and mechanical properties of polymers (through chain scission or cross-linking). L. A. Pruitt from UC Berkeley has reviewed the specific behaviour of the different medical polymer classes to y- and high-energy electron irradiation and environmental effects. The biocidal efficiency refies on free radical formation and on the ability to reduce DNA rephcation in any bacterial spore present in a medical device. 

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