Can anyone explain to me why a bimorph has a metal in between the two piezo-layers?
Maybe it provides the common electrical connection to the far end of the bimorph cantilever.
Are you sure? I've tried searching for it many places but I just can't find anything about it.
No, I'm not sure which is why I say maybe.
It is an educated guess in that to control the two piezo elements independently will require a minimum of three electrical connections.
One of those terminals will be common to both piezo elements and so must reach to the far end of the device.
The metal will be repeatably stretched and contracted as the structure walks. Being on the neutral axis will minimise the metal length change.
There are also fabrication and structural advantages.
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