Novel actuator driven with phase transition of working fluid for uses in wide temperature range

There are many big challenges for manipulation in ultimate temperature environments. Examples of these are in material sciences and industries. For example, steel industries desire new methods for direct handling of materials in temperature higher than 1000 degree Celsius while material scientists desire new method for handling specimen in helium temperature, where higher-quality analysis can be carried out with very low thermal noises. However, conventional actuators don´t work in such environments because of their low thermo-stability and more essential reason of the loss of the magnetic and piezoelectric properties of actuator materials. It us well known that magnetism and piezoelectricity completely disappear in temperature higher than Curie-Point, for example. This report proposes a new working principle of actuators for the uses in very wide temperature range. It is driven by volume change associated with phase transition of working fluid. We propose the principle of this actuator and show the possibilities of the actuator design including the possible selections of temperature-resistant materials and working fluids in various temperatures. In addition, as the first step of this research, we designs the first prototype actuator, working successfully at 180 degree Celsius utilizing liquid-vapor transition of water and the basic experiments results, which shows the great possibility of this actuator.