The micro-pipette was fabricated by pulling a borosilicate glass capillary (inner diameter 0.84 mm, outer diameter 1.5 mm, length 10.16 cm, from World Precision Instruments) with a Sutter P-97 Flamming/Brown micro-pipette puller. The resultant tip diameter was in the range of 5 -6 μm and the diameter of the DCB droplet was in the range of 300 -500 μm. Manual micropositioners (Thor Labs) were used to control the position of the substrate and the pipette. After droplet deposition the micro-pipette was retracted from the surface and the CE and RE were carefully placed in the quartz container.