AVS 51st International Symposium
    Surface Science Monday Sessions
       Session SS-MoP

Paper SS-MoP28
Potential-induced Surface Stress at the Solid-liquid Interface Measured with a Differential Microcantilever-based Sensor

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: V. Tabard-Cossa, McGill University, Canada
Authors: V. Tabard-Cossa, McGill University, Canada
M. Godin, McGill University, Canada
L.Y. Beaulieu, Memorial University, Canada
R.B. Lennox, McGill University, Canada
P. Grutter, McGill University, Canada
Correspondent: Click to Email
We report on a differential microcantilever-based system capable of measuring surface stress changes which occur during electrochemical reactions. Our system is composed of two microcantilever sensors. The first active microcantilever serves as the working electrode (in a conventional three-probe electrochemical cell configuration) and as the mechanical transducer (bending of the microcantilever), yielding simultaneous, real-time, in situ measurements of the current and interfacial stress changes. A second microcantilever serves as a reference sensor to detect any unwanted cantilever deflection resulting from temperature variations, mechanical vibrations and/or uncontrolled chemical reactions. This micromechanical cantilever sensor has a deflection sensitivity of 0.2 nm, which translates to a surface stress sensitivity of 1x10@super -4@ N/m with a dynamic range up to 50 N/m. This system is used to study the potential-induced surface stress at the solid-liquid interface for the case Au in 0.1 M HClO@sub 4@. The dependence of surface stress on surface charge density is examined for different Au surface morphologies. The role played by the morphology of the sensing substrate in microcantilever sensors is studied in order to understand the origin of the surface stress responsible for the sensor's response.