4.1.2 Variation of the starting interface z0 between Casimir electrodes: PZT

We notice (Figure 16) that the vibration frequency of the structure drops as the initial space between the Casimir electrodes increases, which is related to a decrease in the Casimir Force and therefore makes sense. The vibration frequency depends on the chosen FCO=FCA ratio. This frequency drops and stabilizes around 2.6 MHz as the electrode interface increases by a ratio of 200. It is much lower than the first resonant frequency of the structure which is 6.85 Megahertz (for this structure). The vibration frequency approaches that of first resonance if the starting z0 interface is less than 200 Angstroms.

We chose an initial interface of 200 A° for reasons of technological feasibility (see VI)!

We also notice (Figure 17) that the threshold voltage of the Enriched and Depleted MOS transistors increases with a decrease in the starting interface

#### Figure 16.

Threshold Voltage = f (length of the casimir electrode ls), starting interface = 200 A °, selected coefficient of proportionality p = FCO / FCA = 2.

#### Figure 17.

Threshold voltage of the MOS = f (width of the casimir electrode bp), starting interface = 200 A °, selected coefficient of proportionality = p = FCO / FCA = 10.

Perspective Chapter: Device, Electronic,Technology for a M.E.M.S. Which Allow… DOI: http://dx.doi.org/10.5772/intechopen.105197

between Casimir electrodes. This seems logical, since the Casimir force increasing, the deflection of the bridge and therefore the charges generated on its faces do the same. It is therefore necessary that the threshold voltage of the MOS transistors be greater so that the voltage VG on the gates of the MOS does not trigger them!!

#### 4.1.3 Current and threshold voltage function of the length ls of the Casimir electrode: PZT

We obtain (Figure 18) a small decrease in current with the increase in the length of this electrode. However, a significant increase in the threshold voltage (Figure 19), which is understandable since the inertia of the structure increases.

We obtain (Figure 18) a small decrease in current with the increase in the length of this electrode and a significant increase in the threshold voltage (Figure 19), which is understandable since the inertia of the structure increases.

#### 4.1.4 Variation of the width bp of the piezoelectric bridge: PZT

We now vary the width bp of the piezoelectric bridge. We obtain an increase in the threshold voltage of the MOS by increasing the width bp of the piezoelectric

#### Figure 18.

Maximum current = f (width of the casimir electrode bp), starting interface = 200 A °, selected coefficient of proportionality = p = FCO / FCA = 10.

#### Figure 19.

Current of the MOS = f (Thickness of piezoelectric film ap), start Interface = 200 A ° with a choice FCO / FCA =10.

#### Figure 20.

Threshold of the MOS = f (Thickness of piezoelectric film ap), start Interface = 200 A ° with a choice FCO / FCA =10.

#### Figure 21.

Structure vibration frequency as a function of the thickness ap of the piezoelectric bridge, starting interface z0 to 200 A °, Ratio p = FCO / FCA = 10.

bridge. However, the current delivered by the structure varies little with the width of the piezoelectric bridge (Figures 20 and 21). These considerations give that:

For reasons of technological convenience, it will be preferable to choose a thickness of around 20 μm!

#### 4.1.5 Variation of the thickness ap of the piezoelectric bridge: PZT

If we increase the thickness ap of the piezoelectric bridge, we obtain a decrease in the current (Figure 22) and of the threshold voltage of the MOS (Figure 23), but an increase in the vibration frequency (Figure 24).

The vibration frequency increases linearly with the thickness of the piezoelectric bridge (Figure 25).
