The Scanning Droplet System incorporates a technique which confines a liquid in contact with a sample surface in order to measure electrochemical and corrosion reactions over a limited region where the droplet is actually in contact with the sample.

This offers the ability to spatially resolve electrochemical activity and to confine it exclusively to a quantifiable area of the sample.

Uniscan Instruments are the first to market with a commercial product but the technique has been used for fundamental research in laboratories around the world with custom built systems.

Application areas:

• Characterization of surface oxides
• Investigation of coatings
• Characterization of ISFETs
• Investigation of pitting corrosion 
• Localised corrosion versus flow rate

Ecorr changes due to flow rate variation

The SDS370 uses a precision peristaltic pump to deliver precise amounts of electrolyte to the sample surface. The technique as quoted in the scientific literature employs a glass theta capillary to deliver the drop to the surface but Uniscan have engineered a more robust design from PTFE without sacrificing any functionality.  The counter and reference electrode are contained within the PTFE capillary block.

The scanning droplet system allows a spatially resolved, in-situ investigation by the standard electrochemical techniques such as line scans, area maps, potentiostatic pulse steps and open circuit measurements. The electrolyte flow through the cell is controlled via a precision peristaltic pump thus ensuring a good reproducibility of the free droplet wetted area.