Akiteru Fujii

Chemical oscillations in Ru byp 2+ 3 Langmuir monolayers formed on Belousov-Zhabotinskii reaction solutions

Abstract A new approach to external perturbation and control of two-dimensional pattern structures in Langmuir monolayers is presented. The method utilizes the conventional Belousov-Zhabotinskii (BZ) chemical oscillator as a subphase for monolayer formation. It is found, by using fluorescence microscopy, that propagating chemical waves are formed in Ru(bpy)32+ monolayers on Ce4+-catalyzed BZ reaction solutions, reflecting periodic Ce4+Ce3+ changes in the subphase. This system shows high sensitivity to illumination with visible light, and inhibition of wave propagation is clearly observed in the microscopic field.

Optical neural device based on memory-type organic photoconductors

A variable-sensitivity organic-photoconductive device has been developed by using a memory-type organic photoconductor. The device is composed of an input layer and a memory layer acting as a charge generation and a charge transport layer, respectively. A persistent high-sensitivity state, which corresponds to a modulation of synaptic weights in a neuron model, was obtained by blue light illumination. A photochemical reaction of thiomichlers ketone (TMK) in the memory layer was found to be responsible for the memory formation. As a potential application of this memory-type organic photoconductor to an optical neural device, 2-D pattern storage and calculations were performed successfully.