High-speed large area atomic force microscopy using a quartz resonator

Abstract

A high-speed atomic force microscope for scanning large areas, utilizing a quartz bar driven close to resonance to provide the motion in the fast scan axis is presented. Images up to 170 × 170 μm have been obtained on a polydimethylsiloxane (PDMS) grating in 1 s. This is provided through an average tip-sample velocity of 28 cm s at a line rate of 830 Hz. Scan areas up to 80 × 80 μm have been obtained in 0.42 s with a line rate of 1410 Hz. To demonstrate the capability of the scanner the spherulitic crystallization of a semicrystalline polymer was imaged in situ at high speed.

Development of a Resonant Scanner to Improve the Imaging Rate of Astigmatic Optical Profilometers

“…However, the sample size is extremely limited due to the size of the tuning fork [21]. To overcome this issue, different designs such as the quartz bar and the piezoelectric bimorph-based scanner were proposed [22]- [25]. The quartz bar scanner developed by Zhao et al achieved a travel range of 37.5 μm at its resonant frequency of 772 Hz [22].…”

“…Wang et al further demonstrated that the travel range and the resonant frequency can be designed through modifying the length of the quartz bar. Through using a long quartz bar with a size of 4 mm × 5.5 mm × 66 mm (thickness × height × length), a large travel range of 170 μm was achieved at its resonant frequency of 830 Hz [25]. Both the quartz bar and bimorph-based scanners utilize the first resonant mode of the cantilever beam structure to magnify the travel range.…”

Nanopositioning with piezoelectric actuators: Modeling, control, and applications

“…High-speed AFM scanners have been developed by using piezoelectric actuators with ultrahigh resonant frequency [100,102], however, the imaging speed increase was achieved by sacrificing the scan range by at least 80% compared to normal AFM scanners and the hardware modification cost was significant. Although it has been tried to overcome this limit [103,104] by using piezoelectric actuator with ultra-high resonant frequency and the tip velocity could reach as fast as 28cm/s, such a speed improvement is associated to extra hardware cost. More importantly, the imaging force cannot be effectively controlled.…”