Electrochemical printing (EcP) is a software reconfigurable tool and process for electrodeposition of multi-scale, multi-material objects from input drawings. The EcP system—comprising custom LabVIEW print driver software, hardware, electrolyte and a microjet print nozzle—creates complex patterns by locally electroplating individual metal and alloy dots as the microjet rasters over a substrate. The rastering of a microjet just a few microns above the substrate provides extraordinary convective mass transfer rates, allowing material growth rates that are routinely two orders of magnitude greater than in conventional plating. EcP has the flexibility to vary the print resolution and material composition during the patterning process via real time control of the microjet fly height, electrolyte flow rate and applied current. Microjet fly-height is used to vary the print resolution from 50 to 1000 dots per inch during the printing of a copper pattern. Simultaneous control of electrolyte flow rate and applied current through the microjet nozzle is used to achieve high plating efficiencies, well-formed dots and alloys of specific compositions for the copper and nickel–copper systems. It is also shown that commercially available noble metal plating baths can be used in the EcP tool, despite the unusually large current densities achievable and the complexity of commercial bath additives. Issues associated with making EcP a robust tool for 2D and 3D microfabrication are discussed.

Latex gloves of five different thicknesses (0.21 mm, 0.51 mm, 0.65 mm, 0.76 mm, and 0.83 mm) were manufactured in-house and tested for dexterity and tactility; dexterity and tactility measures with the bare hand were used as control values. Fifteen adult males (mean age = 22.8 years, mean stature = 179 cm, mean body weight = 75.4 kg, mean palm width = 9.9 cm, mean palm depth = 10.9 cm, and mean middle finger length = 9 cm) and five adult females (mean age = 21.2 years, mean stature = 168 cm, mean body weight = 53.6 kg, mean palm width = 8 cm, mean palm depth = 8 cm, and mean middle finger length = 8.3 cm) voluntarily participated. The gloves also were tested for punctures resulting from impact forces encountered during routine hand movements. The results indicated that the latex glove with 0.83 mm thickness successfully resisted routine impact forces and at the same time provided dexterity and tactility comparable to the bare hand. Thinner gloves failed the impact test and punctured. This indicates that it is possible to greatly reduce the incidence of exposure to contaminated body fluids through accidental needlesticks without compromising the preferred hand's capabilities.

Electrochemical printing (EcP) is a multi-scale freeform fabrication method employing localized electrodeposition beneath a rastering microjet print head flying microns above the deposition substrate. As a result of the confined geometry and unusual electrochemical configuration, conventional in situ diagnostics are difficult to implement. We show that EcP microfabrication on an electrochemical quartz crystal microbalance (EQCM) allows in situ characterization of the electrochemical processes occurring locally beneath the microjet print head and over large patterned areas where corrosion occurs. Copper deposition experiments show the microjet print head can produce extraordinary mass transfer limiting currents (in excess of 10 A cm−2). The current efficiency for EcP patterning of copper on gold is limited by oxygen reduction at low applied currents and by hydrogen evolution at high currents. Nonetheless, the maximum current efficiency is >90% over two orders of magnitude change in microjet flow rate; the limiting current varies five-fold over the same flow rates. Calibration of the EQCM local sensitivity factors allows characterization and control of corrosion rates when printing extended patterns.