A high-speed atomic force microscope (HS-AFM) requires a specialized set of hardware and software and therefore improving video-rate HS-AFMs for general applications is an ongoing process. To improve the imaging rate of an AFM, all components have to be carefully redesigned since the slowest component determines the overall bandwidth of the instrument. In this work, we present a design of a compact HS-AFM scan-head featuring minimal loading on the Z-scanner. Using a custom-programmed controller and a high-speed lateral scanner, we demonstrate its working by obtaining topographic images of Blu-ray disk data tracks in contact- and tapping-modes. Images acquired using a contact-mode cantilever with a natural frequency of 60 kHz in constant deflection mode show good tracking of topography at 400 Hz. In constant height mode, tracking of topography is demonstrated at rates up to 1.9 kHz for the scan size of $1\mathsf{\mu }\mathrm{m}\times 1\mathsf{\mu }\mathrm{m}$ with $100\times 100$ pixels.

Piezoelectric actuators (PEAs) are extensively used for scanning and positioning in scanning probe microscopy (SPM) due to their high precision, simple construction, and fast response. However, there are significant challenges for instrument designers due to their nonlinear properties. Nonlinear properties make precise and accurate control difficult in cases where position feedback sensors cannot be employed. However, the performance of PEA-driven scanners can be significantly improved without position feedback sensors if an accurate mathematical model with low computational costs is applied to reduce hysteresis and other nonlinear effects. Various methods have been proposed for modeling PEAs, but most of them have limitations in terms of their accuracy and computational efficiencies. In this research, we propose a variant DenseNet-type neural network (NN) model for modeling PEAs in an AFM scanner where position feedback sensors are not available. To improve the performance of this model, the mapping of the forward and backward directions is carried out separately. The experimental results successfully demonstrate the efficacy of the proposed model by reducing the relative root-mean-square (RMS) error to less than 0.1%.

Atomic force microscopy (AFM) is one of the frequently used microscopy techniques to capture high-resolution images in science and engineering. Since the spatial resolution limit of AFM has been mostly reached and no further improvement is likely, much of the recent attention in the development of new AFM has been on improvement of speed. We present a photo-thermal, high-speed atomic force microscope scan head capable of exciting cantilevers photo-thermally and detecting cantilever motions with an optical beam bounce technique. The design features a unique Z-collar that permits direct mounting of a Z-scanner onto a microscope objective lens to achieve a high mechanical bandwidth. We demonstrate the performance of the developed scan head by imaging data tracks of a Blu-ray disk in tapping and contact modes.