High speed tapping mode atomic force microscopy in liquid using an insulated piezoelectric cantilever

Quicker imaging times for tapping mode atomic force microscopy in liquid could provide a real-time imaging tool for studying dynamic phenomena in physiological conditions. We demonstrate faster imaging speed using microcantilevers with integrated piezoelectric actuators. The exposed electric components of the cantilever necessitate an insulation scheme for use in liquid; three coating schemes have been tested. Preliminary tapping mode images have been taken using the insulated microactuator to simultaneously vibrate and actuate the cantilever over topographical features in liquid, including a high speed image of steps on a mica surface in water and an image of two e coli bacteria taken in saline solution at 75.5 μm/s, a threefold improvement in bandwidth versus conventional piezotube actuators.