State of the art telemetric implantable sensors and their encapsulation

MEMS sensor have the potential to revolutionize medical implants. Their advantages are a small form factor, low power consumption and the ability to operate by telemetry. While some MEMS sensors, for example to measure pressure, have reached a high level of maturity, their encapsulation for long term implants remains problematic. Here, a novel encapsulation a technique is presented that combines flexibility with long term stability. It relies on a two layer approach: the outer thicker layer consists of a polymer, while the inner layer consists of a stack of thin layers which is long term stable and water vapor impenetrable. Furthermore, the discussed pressure sensor can be operated wirelessly, therefore no battery is required. The operation is described, and some initial measurement data on animal trials are presented