4.2.2 Piezoelectric material = AlN

With the MATLAB simulation of the behavior of the structure for piezoelectric Aluminum Nitride (AlN), we obtain the evolution with the time of the Casimir and Coulomb forces as well as the FCO=FCA ratio of Figures 40 and 41 below. For a ratio FCO=FCA of 10, the maximum current delivered by the vibrating structure, the threshold voltage of the MOS and the vibration frequency of the structure is respectively 1.85 10<sup>7</sup> A, Vt = 3.7 V and 667,000 Hertz.

Figure 40. Piezoelectric Material = AlN. Ratio FCO / FCA = f(Time). Start interface = 200 A °.

#### Figure 41.

Material = AlN Interval between Casimir electrodes = f (time) during two complete cycles: Interface between starting electrodes = 200 A °.

Figure 42. Principle of electronics for amplifying and rectifying a week AC signal.

We observe (Figure 42) that the ratio p ¼ FCO=FCA barely equals 2, and that the time of "rise" of the mobile Casimir electrode is relatively slow, it is a consequence of the low value of the piezoelectric coefficient d31 of AlN.

In conclusion, the use of AlN does not seem suitable for this vacuum energy extraction application.

#### 4.3 Conclusions

It seems that for the piezoelectric material we used, the most suitable piezoelectric material for this vacuum energy extraction device is PMN-PT with a peak current of 350 m A, at least for the materials we used for the previous simulations (Figures 7, 31–39).

In order to convert these alternating current peaks into an alternating voltage without input of energy, this current passes through a LIN inductor coil which converts these current peaks without input of external energy into voltage peaks of several volts and of a duration of the order of the nanosecond.

Inductors LIN for printed circuits of the order of 100μH or less are conventional and are commercially available.

The next chapter proposes to convert these peaks of alternating voltage, to amplify them to obtain a direct voltage of several volts without any external power supply!
