## 3 Results
### Tunneling Verification  
In accordance with the findings from the HRTEM analysis, the 340 pA FEB and the 9 pA and 260 pA FIB tips are tested for their suitability for the quantum mechanical tunneling mechanism across a vacuum gap by integration into a MEMS. Figure 9 shows the measurements when the tips approach distances of a few nm at which the tunneling effect occurs and the subsequent removal of the tips. Since measurements with the FEB tip show no increasing current, either as contact or tunneling behavior, the presentation of the measured results is omitted. It is suggested that the huge amount of DLC, especially in the edge area, leads to a high ohmic contact; therefore, no current flows between the electrodes. In the case of the Pt tips, the tunneling effect only occurs when two Pt grains face each other at the tunneling distance of a few nm. If two Pt grains meet each other, an exponentially increasing current curve occurs when the distance is shortened linearly. Thus, the electrostatic behavior is quadratic regarding the deflection by increasing the actuator voltage. However, the deflection range concerning the tunneling distance is so small that it can be assumed to be quasi-linear. When a Pt grain or an amorphous DLC region meets another DLC region, either no current flows or only when the tips get into ohmic contact. In the latter case, this is visible by a jump in the current waveform. According to the excitation principle, the actuator voltage (green line) is increased until the tunneling electrodes are  
Figure 8: Measurements of twenty individual Pt crystallite of the 340 pA FEB, 9 pA FIB and 260 pA FIB tips. Figure 7: Images of **(a)** the 340 pA FEB, **(b)** 9 pA and **(c)** the 260 pA FIB tip, **(d,f,i,j)** and **(k)** the SAEDs and (e,g) and **(h)** its FFTs. only a few nm apart. The voltage values from Figure 9a,b depend on the initial distances of the tips and therefore defer from each other. The orange line in Figure 9a,b marks the current threshold at 100 pA for the measurement algorithm to detect the occurrence of the tunneling or contact current and to retreat the electrode. For the measurements, a tunneling voltage of 1 V is applied to each of the electrodes. Figure 9 shows reproducible curves of the current over the measurement time with repeated approaches and removal of the tips. The offset of the measurements is slightly below the 0 A mark in each case due to leakage currents through the wiring, the measurement system, and the conductive tracks on the PCB and MEMS chip. The measurement algorithm causes the voltage to increase in 1 to 5 mV steps on the electrostatic actuator until the current threshold is reached. The voltage is then lowered to move the tips away from each other and then approached again. Figure 9a shows the measurement when the 9 pA tip is approached. In most cases, the current waveform can be seen as a drop in the device signal. This indicates an instant ohmic contact without electron tunneling. Accordingly, an electrical connection is established only by direct contact of the tips corresponding to the conduction mechanism in metal-organic materials. After a sudden increase of the current by contact of the electrodes and subsequent decrease of the actuator voltage, the electrodes adhere to each other by the surface forces until the counteracting force of the PolySi beam overcomes them. This moment can be seen by the abrupt drop in the current waveform back to 0 A. Additionally, the characteristic gradually decreasing current is marked by the red arrows caused by a decreasing attractive force due to the tips pulling apart. Figure 9b, on the other hand, shows the characteristic measurement with a 260 pA FIB tip. With these tips, an exponentially increasing current waveform is apparent when approaching, and an exponentially decreasing current waveform is apparent when moving away the electrodes.