This paper explores a possibility of constructing massively parallel molecular computing systems using molecular electronic devices called enzyme transistors. The enzyme transistor is, in a sense, an artificial catalyst which selects a specific substrate molecule and transforms it into a specific product. Using this primitive function, various active continuous media for signal transfer/processing can be realized. Prominent examples discussed in this paper are: (i) Turing pattern formation and (ii) excitable wave propagation in a two-dimensional enzyme transistor array. This paper demonstrates the potential of enzyme transistors for creating reaction-diffusion dynamics that performs useful computations in a massively parallel fashion.

This paper reviews the potential possibility and present status of trans-polyacetylene research toward realization of soliton molecular devices utilizing characteristics of the quasi-one-dimensional conductor. Properties of solitons in polyacetylene are summarized from a point of view to produce a new microelectronics beyond Si-LSI's. The limiting performance of soliton LSI's are roughly estimated. One bit information is stored in only 420 2. The information transmission rate of a wiring is 2104 Gb/s. The delay time per gate is 0.05 ps. For realization of this high performance devices, a lot of research must be carried out in future. A new circuit with new principles of operations must be developed to achieve the performance, where a localized soliton or a localized group of solitons are treated. Some systems, which may lead to development of logic circuits, are proposed. The problems in crystal quality and fabrication process are also discussed and some means against them are presented.