Light guides emit light from the side surface thereof toward the subject to be read, the light emitted to one end surface of each of the light guides. The concave shape optimizes surface area within a small volume and thereby enables the capacitor to hold a significant charge so as to assist in increased miniaturization efforts in the microelectronic field. According to various embodiments, a reaction device is placed in an environment in order to perform a chemical reaction in an environment. The first and second axes provide pivoting of the skateboard in two dimensions.