601 after the fourth etching process an x line metal layer 116 is deposited on the first protective layer 114 as shown in fig8 a and 8b the x line metal layer 116 is deposited by a process such as sputtering cvd plasma cvd pvd or the like the x line metal layer 116 is typically composed of aluminum or an aluminum alloy as shown in fig8 c the x line metal layer 116 fills the contact opening 703 in the first protective layer 114 and is thus electrically connected to the top electrode 104 of the partially completed piezoelectric cantilever 801 next a fifth etching process that uses a fifth mask is performed to define the x lines 302 and x pads 306 in the x line metal layer 116 as shown in fig9 a 9c the fifth etching process removes the unmasked portion of the x line metal layer 116 to define the x lines 302 and the x pads 306 and additionally exposes the first protective layer 114 after the fifth etching process a second protective layer 118 is deposited on the layer structure 180 by spin coating as shown in fig1 a and 10b the second protective layer prevents direct contact between the fingertip and the x lines 302 the second protective layer 118 is composed of any material that meets the heat resistance chemical resistance and insulation requirement the second protective layer 118 is also flexible enough to allow repeated deformation in one embodiment the second protective layer 118 is composed of polyimide and has a thickness of about 2 7 u03bcm after the second protective layer 118 is deposited the layer structure 180 is subject to a sixth etching process that uses a sixth mask the.