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VS-SDC Scanning Droplet Cell

Scanning Droplet System (SDC) uses a compact peristaltic pump to force electrolyte through a small diameter tube and into a specifically designed head. This PTFE-based SDC head is machined to allow electrolyte to flow past an installed Reference Electrode and then to a port at the base of the head.

When the head is positioned sufficiently close to the sample a droplet forms between the head and sample. Tubing is also connected to an output port of the PTFE head. A second channel of the same peristaltic pump is then used to draw electrolyte past an installed Counter Electrode and out of the system.  SDC experiments can be configured to either:
  • Apply a constant bias (potential, current or open (circuit) and increment position of the head creating a data map.
  • Apply a static or dynamic electrochemical signal, such as a EIS experiment, a Tafel plot, or a Cyclic Voltammetry experiment as the head is kept in a fixed location.
Since electrochemistry occurs at an electrode/electrolyte interface, only the portion of the sample that is in contact with the droplet is being measured. This allows experiments to study a small area of a large sample, without cutting the sample and thus limiting edge effects.

When running, the SDC pump creates a flowing droplet. SDC’s pump velocity can be tuned to study different effects of flow rate.

  • SDC technique confines the electrochemical measurement to the small droplet of electrolyte, defining the area of the electrode/electrolyte interface.
  • Samples can be investigated without cutting the sample or subjecting areas to different electrolyte exposure times.
  • Capable of running both constant bias/swept position plots for data maps and fixed-position/ dynamic signal plots for Cyclic Voltammetry, Tafel, EIS, etc.
  • Documents +

  • Specifications +

    Compliance Voltage ±12V
    Polarization Voltage ±10V
    Current Ranges and Resolution
    VersaSTAT 4 4nA to 1Astandard;120fA on 4nA range
    VersaSTAT 3F 4nA to 650mA standard; 120fA on 4nA range
    VersaSTAT 3 200nA to 650 mA standard; 6pA on 200nA range
    SDC Head
    Material PTFE
    Aperture 500-micron diameter
    Reference Electrode Ag/AgCl
    Counter Electrode Pt wire
  • Options +

    L-Cell VersaSCAN L-Cell
    • Screws into optical table of VersaSCAN
    • Approximately 1 Liter in volume
    • Level adjustment mechanism
    • Accepts large flat samples and 32-mm diameter mounted samples
    • Recommended for all techniques, particularly LEIS, SVET, SKP, SDC, OSP
    VersaCAM VersaCAM
    Long Working Distance Video Microscope
    • Camera:
      • Color
      • Number of pixels: 795 (H) x 596 (V)
      • Minimum illumination 0.02 lx. F1.2
      • Power: 12V DC ±10%
      • CS-mounted or C-mount with provided adapter
    • Lens:
      • C-Mount
      • Manual focus
    • Display:
      • 8 inch color TFT display
      • PAL & NTSC auto selection
      • 640x480 (307,200 pixels) screen resolution
  • Video +

    Watch video demonstrations of the VS-SDC Scanning Droplet Cell

  • Experiments +

    Line Scan This experiment applies a constant polarization while scanning the SDC head, and thus the droplet, across the surface in one direction while the response is measured. Measurable responses are current (applied voltage), voltage (applied current), or open-circuit potential (no signal applied.
    Area Scan SDS Area Scans are X-Line Scan experiments at incremented positions in the Y-direction. This XY plane is graphed as a map. The same parameters are capable of being measured as in the Line Scan experiment. When running a SDS Area Scan experiment, the potentiostat’s current measurement range auto-ranges. Step-scan is recommended for oversampling and averaging of the data.
    Non-Scanning, Fundamental
    The VersaSTATs can run a wide variety of non-scanning fundamental experiments with the VersaStudio environment. Please reference the brochure or webpage of your specific model of potentiostat for complete details on its non-scanning experiments. These experiments would be performed with the droplet in a fixed location