Flexure mechanisms have been widely used for nanometer positioning systems. This article presents a novel conceptual design of an ultra-precision 3-degrees of freedom (XYθ(Z)) positioning system with nanometer precision. The main purpose of this novel stage design is for the application of measurement equipment, in particular biological specimens. The stage was designed as a hollow type and with a compact size for the inverted microscope. This stage includes piezoelectric transducer actuators, double compound amplification mechanisms, moving plate, and capacitor sensors. The double compound amplification mechanism was designed using a mathematical model and analyzed by the finite element method. Since the relationship between the variables of the hinge parameters and system performances are complicated, an optimization procedure was used to obtain the optimal design parameters, which maximized the system bandwidth. Based on the solution of the optimization problem, the design of the stage and FEM simulation results are presented. Finally, the stage was manufactured and tested.
During rolling stock operation, various kinds of energy such as vibration, heat, and train-induced wind are dissipated. The amount of energy dissipation cannot be overlooked when a heavy railroad vehicle operates at high speed. Therefore, if the wasted energy is effectively harvested, it can be used to power components like low power sensor nodes. This study aims to review a method of collecting waste heat, caused by the axle bearing of bogie in a rolling stock. A thermoelectric module (TEM) was used to convert the temperature gradient between the surface of the axle bearing housing and the outdoor air into electric energy. In this study, the output performance by temperature difference in the TEM was lab-tested and maximized by computational fluid analysis of the cooling fins. The optimized thermoelectric energy harvesting system (TEHS) was designed and applied on a rolling stock to analyze the power-generating performance under operation. When the rolling stock was operated for approximately 57 min including an interval of maximum speed of 300 km/h, the maximum open circuit voltage was measured at approximately 0.4 V. Based on this study, the system is expected to be utilized as a self-powered independent monitoring system if applied to a low-power sensor node in the future.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.