An implantable device having an impact side likely to receive forces applied to the device is disclosed, the device comprising: a hermetically-sealed container including, a chassis having secure thereto at least one functional component, a first shell hermetically connected to the chassis to form a hermetic enclosure in which the at least one functional component is located, at least on feedthrough disposed in one or more of either the chassis and the first shell, configured to permit at least one input/output line to infiltrate the hermetic enclosure； and a second shell connected to the container so as to be spaced from and adjacent to the container to define the impact side of the device and to form with the container a non-hermetic enclosure.
