We identify the dynamics of an atomic force microscope ~AFM! in order to design a feedback controller that enables faster image acquisition at reduced imaging error compared to the now generally employed proportional integral differential ~PID! controllers. First, a force model for the tip–sample interaction in an AFM is used to show that the dynamic behavior of the cantilever working in contac...

Vibration is a key factor to be considered when designing the mechanical components of a high precision and high speed atomic force microscope (AFM). It is required to design the mechanical components so that they have resonant frequencies higher than the external and internal vibration frequencies. In this work, the mechanical vibration in a conventional AFM system is analyzed by considering i...

Multi-frequency atomic force microscopy (MF-AFM), employing the detection and/or excitation of multiple cantilever frequencies, has shown great promise in increasing the compositional sensitivity, and the spatial and temporal resolution of imaging. The multitude of frequency components generated in MF-AFM encode information about the tip-sample nonlinearity. For quantitative interpretation of t...

Atomic force microscopy (AFM) was applied to carry out direct and label-free detection of gp120 human immunodeficiency virus type 1 envelope glycoprotein as a target protein. This approach was based on the AFM fishing of gp120 from the analyte solution using anti-gp120 aptamers immobilized on the AFM chip to count gp120/aptamer complexes that were formed on the chip surface. The comparison of i...

A cell's form and function is determined to a great extent by its cellular membrane and the underlying cytoskeleton. Understanding changes in the cellular membrane and cytoskeleton can provide insight into aging and disease of the cell. The atomic force microscope (AFM) allows unparalled resolution for the imaging of these cellular components and the ability to probe their mechanical properties...

Scanning probe microscopy (SPM) has been in use for 30 years, and the form of SPM known as atomic force microscopy (AFM) has been around for 25 of those years. AFM has been used to produce high resolution images of a variety of samples ranging from DNA to carbon nanotubes. Type I collagen and many collagen-based tissues (including dentin, tendon, cartilage, skin, fascia, vocal cords, and cornea...

Atomic force microscopy (AFM) was used as a meaningful tool to characterize the nanostructure of gelatin from catfish (Ictalurus punctatus) skin. The gelatins extracted with pretreatments including acid pretreatment, alkaline pretreatment, and alkaline followed by acid pretreatment (optimized extraction conditions). The resulting gelatins were imaged using AFM and their nanostructure was studie...

A novel calibration technique has been developed for lateral force microscopy (LFM). Typically, special preparation of the atomic force microscope (AFM) cantilever or a substrate is required for LFM calibration. The new calibration technique reported in this paper greatly reduces the required preparation processes by simply scanning over a rigid step and measuring the response of the AFM photod...

Non-contact atomic force microscopy (NC-AFM) is a powerful tool for the atomic level observation of various kinds of surfaces including even insulators, and it has been rapidly developed [1]. While the main observable value in the scanning tunneling microscope (STM) is a tunneling current between a tip and a surface, the main observable value in NC-AFM is a frequency shift of the cantilever osc...

A hybrid atomic force microscopy (AFM)-optical fluorescence microscopy is a powerful tool for investigating cellular morphologies and events. However, the slow data acquisition rates of the conventional AFM unit of the hybrid system limit the visualization of structural changes during cellular events. Therefore, high-speed AFM units equipped with an optical/fluorescence detection device have be...