Patent ID: 8851637

Claim:
An inkjet device, comprising: a pumping chamber bounded by a wall; a piezoelectric layer disposed above the pumping chamber; a ring electrode having an annular lower portion and an annular upper portion, the annular lower portion being disposed on the piezoelectric layer; and a moisture barrier layer covering a remainder of the piezoelectric layer over the pumping chamber that is not covered by the annular lower portion of the ring electrode, wherein: the annular upper portion of the ring electrode includes an annular inner upper portion and an annular outer upper portion; the annular lower portion of the ring electrode includes an annular inner lower portion and an annular outer lower portion; the annular inner upper portion extends inwardly from the annular inner lower portion to cover a portion of the moisture barrier layer surrounded by the annular inner lower portion; and the annular outer upper portion extends outwardly from the annular outer lower portion to cover a portion of the moisture barrier layer that surrounds the annular outer lower portion.