High-speed Scanning Probe Microscopy
Introduction
As well as making extensive use of scanning probe microscopes (SPMs) to investigate a wide range of
biological and polymeric systems, the Nanophysics and Soft Matter Group is also well known for
developing SPM instrumentation. We have had two main directions in this area; the first has been
the design and construction of both shear-force and
scanning near-field optical microscopes (ShFM and SNOM
respectively), while the second has been focussed on the goal of improving the capabilities of AFM.
One of the biggest limitations in SPM is the serial nature of the data collection, meaning that
the time taken for the probe to address each pixel of the image in turn and then move to the next
forms a bottleneck in the imaging rate. As a result a standard 256 x 256 or 512 x 512 image will
take between 60 and 300 seconds to collect. This prevents the observation of dynamic behaviour
or other events within systems that evolve on shorter timescales. It is therefore a significant
obstacle in the development of SPM techniques for biological systems - where the dynamic behaviour
of the system is likely to take place on the millisecond timescale. These slow scan speeds also
prevent large areas from being imaged in practical timeframes, making the acquisition of sample
statistics a time consuming and laborious process and limiting the usefulness of SPM methods to
commercial and industrial scale processes and applications.
Developments in high-speed scanning probe microscopy follow several lines of investigation. The following pages provide greater details: