Abstract: A first aspect of the present invention is carbon fiber wherein the surface of a monofilament has a center line average roughness Ra of 6.0 nm or more and 13 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. A second aspect of the present invention is carbon fiber precursor acrylic fiber wherein the surface of a monofilament has a center line average roughness Ra of 18 nm or more and 27 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. The carbon fiber according to the first aspect is obtained by stabilizing and carbonizing under specific conditions the carbon fiber precursor acrylic fiber according to the second aspect.

Abstract: A novel optical molding process for forming a three-dimensional article from a photosensitive resin which is liquid at normal temperatures which involves forming a plurality of laminated cured resin layers by a repetition of the step of forming a cured resin layer by selectively irradiating the surface of a photosensitive resin, wherein the photosensitive resin has been coagulated by cooling and the coagulated resin is irradiated to cure it. The process can produce a three-dimensional article having an overhanging part without producing warping in the finished product and without requiring a support for the overhanging part while this part is being optically molded.

Abstract: A fluid-flow regulating device is comprised of (a) a plurality of driving mechanisms each of which has a chamber, a diaphragm disposed at an opening of the chamber, a light-heat conversion substance accommodated in the chamber, and an operating fluid stored in the chamber, (b) a fluid-flow passage along which the plurality of driving mechanisms are arranged in such a manner that each of the diaphragm is opposed to the fluid-flow passage, (c) a plurality of optical fibers corresponding to the plurality of the chambers, and (d) a controller having a plurality of optical sources corresponding to the plurality of optical fibers which are set to be turned on and turned off in order to move an amount of fluid through the fluid-flow passage in any one of the normal and the reverse directions.

Abstract: An actuator is comprised of a main body, an inner space filled with an amount of thermally expansive gas and having a first portion in the form of a shallow configuration with an opening oriented toward one side of the main body, a second portion and a bottleneck passage located therebetween, a membrane in the form of a thin film connected to the side of the main body for closing the opening of the first portion of the inner space, a substance for converting the light into heat, and a guide device for guiding light into the second portion of the inner space. Upon an unexpected application of an external force on the thin film, the deformation of the thin film is limited at minimum by being supported by the bottom surface of the first portion. This ensures the prevention of the breakage of the thin film.

Abstract: An actuator includes a closed space defined by a deformable member in which an amount of thermally expansible gas is filled. In the closed space, there is also a substance which changes the light into the heat. A control device is set to establish the supply of the light into the closed space. Upon turning-on of the control device, the substance changes the supplied light into the heat, resulting in that the resultant heat brings the expansion of the gas. Thus, the member is brought into deformed condition. The deformation can be used as a force for operating a specific element.

Abstract: An actuator is comprised of a main body having an opening at its one side, an inner space defined within the main body and filled with an amount of thermally expansive gas, a substance for converting the light into the heat which is accommodated in the inner space, a guide device for guiding light into the second portion of the inner space, and a membrane connected to the side of the main body for closing the opening and deflected previously toward the inner space so as to establish a snap action toward outward of the main body when the inner pressure exceed a set value.

Abstract: An actuator is comprised of a plurality of three-dimensionally arranged containers each of which is constructed into deformable configuration and each of which is set to accommodate therein an amount of expandable fluid in response to the increase of the temperature, a heat supply device for supplying the heat to the fluid in each of the containers, a cooling device for cooling the fluid in each of the containers and a control device for controlling the heat supply device and the cooling device.