The experimental procedure is separated over 3 phases: the thermal-environmental phase with the combination of factors A, B, C and D. Following is the mechanical step with factors E, F and G over the three axes of the device (X-Y-Z sequentially). Finally, the samples are fixed on the back-plate of the pendulum of the shocks machine and undergo series of 6x5 shocks in all of the 6 main directions of the device. After this sequence, the sample is removed from the jig and its capability to measure the value of gravity is checked. A device is considered as failed either when gravity cannot be measured accurately, either if complete failure occurs.

First step: Thermal-environmental testing

Normally, thermal cycling procedure is either dictated by a standard (MIL-STD-883K, Method 2002), either limited by the apparatus. In the case of this study, the limits of the environmental chamber (ESPEC SH-662) are taken as lower and upper bound. As for the temporal conditions of the thermal cycling procedure, it was proposed to deviate from the standard conditions significantly. Figure 4 shows the thermal cycles built from the matrix of test. The factors has been set on the legacy obtained from MEMS-REAL in order not to overstress the samples in this first step.