Columbia SECM

Scanning electrochemical microscopy (SECM) is a powerful and versatile scanning probe microscopy technique capable of chemical imaging at the nano-micro scales. It has proven to be a valuable tool across the chemical, physical, and biological sciences.

Together with Prof. Yuan Yang in Materials Science, we oversee the operation of a CHI 9200 SECM that was purchased through the Columbia SEAS Research Equipment Assistance Program (REAP).  This instrument is managed through the Chemical Engineering Department at Columbia and is open to all Columbia students and staff for use as a part of their research.  You can find specifications of this instrument below, and a short overview of SECM and its uses in this presentation.

If you are interested in using this instrument, please email columbiasecm@gmail.com for more information and/or to set-up a training session.

CHI 9200 SECM- Specifications & Limitations

  • Scanning capabilities w/ closed loop positioners:
  • Minimum X,Y,Z step size: 1.5 nm
  • Maximum X,Y,Z scan lengths: 50 mm
  • CHI bipotentiostat (2 working electrodes)
  • Measured current accuracy down to 0.1 pA (min. res. 0.3 fA)
  • Impedance analyzer for EIS and impedance mapping.
  • Compliance voltage: ±13 V
  • Sample, electrolyte, & scanning restrictions:
  • Roughness >> desired resolution is very challenging
  • Samples must be stable in electrolyte (unless studying corrosion!)
  • Electrolytes must be air-stable & safe for use in open lab
  • Max scan speed is typically a couple probe radii per second

secm_photo

Photos and schematics modified from: http://www.chinstruments.com/chi900.shtml