Development of an Arduino-Based COIFM Controller

Water is a challenging molecule to study due to its small size. Because water molecules interact weakly with their environment, experiments on water have to be delicate so as not to disturb what one is trying to measure. The quest to understand interfacial properties is virtually hopeless without a detailed characterization of the structure of interfacial water. Recent advances in an experimental technique called atomic force microscopy (AFM) make it possible to conduct in-situ studies of water-material interfaces and acquire a more complete knowledge of the interaction between water and other materials. For the last two decades, we have developed a unique AFM technique called the cantilever-based optical interfacial force microscope (COIFM). The COIFM makes it possible to grab and manipulate water molecules to understand their mechanical behaviors at the nanoscale level. The COIFM overcomes the "snap-to-contact" problem associated with conventional AFM force measurements by using a technique called "force feedback." The COIFM investigation of water in a nanoscale meniscus led to the discovery of a new form of water named "self-assembled water chains." However, the application of the current COIFM system is limited to the laboratory setting because of its expensive bulky controller. To address this issue, we have developed a cost-effective COIFM controller that incorporates Arduino, an inexpensive microcontroller. This Arduino offers several outstanding features, including light weight, affordability, compact dimensions, and high flexibility. The portability of the Arduino-based controller will facilitate the expansion of COIFM water research, making it applicable to both fieldwork and laboratory settings.