Engineers from Park Systems, Santa Clara, Calif., demonstrated how an atomic force microscope, when combined with an ammeter, can provide concurrent topography imaging and electrochemical mapping of a structure, at the ASM International MS&T 2019 Conference in Portland, Oregon.
The SICM-SECM probe consisted of a gold crescent electrode (AuE) of a nanopipette. High-resolution probe-substrate distance was controlled by the ion current feedback from SICM, while simultaneous electrochemical signal collection was achieved via the AuE from SECM.
As a proof-of-concept experiment, a gold/Pyrex pattern standard sample was imaged with the SICM-SECM technique. The gold bar and the Pyrex substrate were clearly resolved from the SICM topography image. On the electrochemical mapping, higher Faradaic current was seen when the probe was scanned over the gold bar as a result of redox cycling, while lower Faradaic current was observed when the probe was over Pyrex.
The capability of the described SICM-SECM technique holds promise of many applications in the field of electrochemistry and materials science.
Simultaneous Topographical and Electrochemical Mapping using Scanning Ion Conductance Microscopy–scanning Electrochemical Microscopy (SICM-SECM)
Gabriela Mendoza, Byong Kim, Keibock Lee, Park Systems
