Medical practice is rapidly approaching the "age of implants." Already pacemakers are routinely implanted and in the near future, a host of devices designed for people with mobility deficits will come into common use. Until now the electronics have received the large share of thought and experiment but now designers must consider the less glamorous matter of what will protect implanted circuits from the hostile environment of the body. These studies will begin by studying the use of silicone elastomers for corrosion control of implanted medical electronic devices through accelerated-life testing in conditions similar to in-vivo experiments; the conditions, however, will be more controllable than in in-vivo testing.