Open-source controller for low-cost and high-speed atomic force microscopy imaging of skin corneocyte nanotextures

High-speed atomic force microscopes (HS-AFMs) with high temporal resolution enable dynamic phenomena to be visualized at nanoscale resolution. However, HS-AFMs are more complex and costlier than conventional AFMs, and particulars of an open-source HS-AFM controller have not been published before. These high entry barriers hinder the populariza-tion of HS-AFMs in both academic and industrial applications. In addition, HS-AFMs gener-ally have a small imaging area that limits the fields of implementation. This study presents an open-source controller that enables a low-cost simplified AFM to achieve a maximum tip-sample velocity of 5,093 lm/s (9.3 s/frame, 512 x 512 pixels), which is nearly 100 times higher than that of the original controller. Moreover, the proposed controller doubles the imaging area to 46.3 x 46.3 lm2 compared to that of the original system. The low-cost HS-AFM can successfully assess the severity of atopic dermatitis (AD) by measuring the nanotexture of human skin corneocytes in constant height DC mode. The open-source controller-based HS-AFM system costs less than $4,000, which provides resource-limited research institutes with affordable access to high-throughput nanoscale imaging to further expand the HS-AFM research community.(c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

High-speed atomic force microscopes (HS-AFMs) are capable of visualizing dynamic phenomena at nanoscale resolution with high temporal resolution. However, the complexity and cost of HS-AFMs, coupled with the lack of published information on open-source HS-AFM controllers, have hindered their widespread adoption in academia and industry. Furthermore, the limited imaging area of HS-AFMs restricts their potential applications. This study introduces an open-source controller that enables a low-cost simplified HS-AFM system with significantly improved tip-sample velocity and imaging area. The proposed system successfully assesses the severity of atopic dermatitis by measuring the nanotexture of human skin corneocytes. By providing affordable access to high-throughput nanoscale imaging, the low-cost HS-AFM system based on the open-source controller enhances the research capabilities of resource-limited institutes and contributes to the expansion of the HS-AFM research community.