measured at V = -5 V and with geometric contact areas a = 4-12 µm 2 is lower than the reported values of log 10 |J 0 | = 2.2 ± 0.3 for EGaIn junctions based on cone-shaped tips measured at V = 0.5 V and with a = 300-500 µm 2 . 14,32,63 A possible explanation for this discrepancy is that the contact forces applied in the cone-shaped tip junctions (∼ µN) are higher than in this work (∼ nN), resulting in plastic deformation of the oxide monolayer, a smaller tunneling gap, and hence higher J 0 . In this work, we also fabricated the microdroplets in ethanol (dispersant medium during ultrasonication) as opposed to air in cone-shaped tips, which can result in an oxide layer of different thickness and electrical conductivity. When exposed to ethanol, EGaIn surface may become covered with a different adventitious layer than freshly-prepared cone-shaped tips made in air. Note that the rectification is expected to be negligible in Au/Cn/EGaIn junctions, i.e., the voltage polarity at which J 0 is extracted is not expected to lead to a significant difference. The junctions also show extreme robustness, and can be subjected to voltages of up to 5V, corresponding to an electrostatic stress of approximately 50 MV cm -1 , compared to a typical breakdown stress of ∼ 8 MV cm -1 in junctions formed using the EGaIn cone-shaped tip method. This 5-6 fold increase in the breakdown field can likely be explained by the formation of smooth contact areas (with no wrinkles or cracks on the gallium oxide layer), which results in a homogeneous electrical field and current flow across the junctions. With rough contacts typically achieved with previous techniques, there can be hot-spots where the electrical field is locally high and breakdown can occur. Additional experiments described in Supporting Figure confirmed that most of the voltage drops across the SAM. Moreover, there are more intrinsic defects where breakdown can occur over the larger area of the cone as compared to EGaIn microspheres. The breakdown event in such structures has been attributed to the transfer of momentum from electrons to the metal atoms as the current passes through the structure, thus creating a conductive path and hence an electrical short-circuit; this momentum transfer is referred to as the wind force. As there is much lower current density J flowing through our EGaIn droplet probe system (and hence smaller wind force), we avoid such electrical breakdown in our structures.