Visualizing Growth and Etch at a Calcite Screw Dislocation- An Example of Liquid Perfusion on a Cypher ES AFM

This video highlights how the Cypher ES AFM enables imaging of fast surface dynamics in liquid as the liquid composition is changed through perfusion. Here, we monitor the growth and etching of a calcite crystal while changing the pH of the surrounding solution. The scan is centered on a screw dislocation, a crystal defect where an atomic step edge remains continuously exposed and can grow or recede in a helical pattern.

We begin by imaging in a basic solution, where new calcite layers grow from the dislocation site. We then briefly perfuse an acidic solution, which immediately etches away several layers. When the solution is exchanged back to a more basic condition, growth resumes. Each time the chemistry changes, the direction of motion around the screw dislocation reverses, making this a clear visual example of how surface processes respond to the liquid environment.

Capturing this behavior requires both environmental control and imaging stability. The modular, pressure-tight Cypher ES sample chamber enables controlled liquid perfusion, delivering solution directly near the scan region without compromising imaging performance. The Cypher ES also provides low lateral drift, keeping the same 500 nm region centered over the full experiment, while its low-noise performance easily resolves 0.3 nm-high atomic steps. blueDrive photothermal excitation helps maintain stable tapping mode imaging in liquid, while fast scanning at roughly 20 lines per second captures a frame about every 7 seconds. Together, these capabilities make the Cypher ES an ideal platform for studying dynamic processes at solid–liquid interfaces in real time.