Abstract: A thermal transpiration flow heat pump includes an evaporator that vaporizes a medium, a condenser that condenses the medium, and a medium transport unit that is provided between the evaporator and the condenser. The medium transport unit includes a medium-temperature heat source portion that is placed on a side of the evaporator, a high-temperature heat source portion that is placed on a side of the condenser, and a thermal transpiration flow pump that is placed between the medium-temperature heat source portion and the high-temperature heat source portion.

Abstract: A thermal transpiration flow heat pump includes an evaporator that vaporizes a medium, a condenser that condenses the medium, and a medium transport unit that is provided between the evaporator and the condenser. The medium transport unit includes a medium-temperature heat source portion that is placed on a side of the evaporator, a high-temperature heat source portion that is placed on a side of the condenser, and a thermal transpiration flow pump that is placed between the medium-temperature heat source portion and the high-temperature heat source portion.

Abstract: A first surface of a porous medium is in contact with a first space. A second surface of the porous medium is in contact with a second space. The first space is in communication with the second space via the pores of the porous medium. Light in a wavelength range where the material of the porous medium exhibits light absorption properties is applied to the first surface of the porous medium from a light source, so that energy of the applied light can be efficiently absorbed into the porous medium from its first surface, and the first surface of the porous medium can be efficiently heated. As a result, a thermal transpiration flow can be efficiently generated in the porous medium, and a pressure difference can be efficiently produced between the first space and the second space.