Membrane Computing: A General View

We give an informal presentation of the basic ideas, results, and applications of membrane computing, a branch of natural computing inspired by the structure and the functioning of biological cells, cell tissues, or colonies of cells. Membrane computing has given rise to computing models (called P systems) that are distributed and parallel, which process multisets of objects in compartments defined by membranes. After introducing the main classes of P systems, illustrated with some simple examples, we recall some results, especially those that concern their computing power and computing effi-ciency: the equivalence with Turing machines for many classes of P systems, and the possibility of designing devices which are capable of solving computationally intractable problems in feasi-ble time. We then briefly discuss some applications (to biology, bio-medicine, economics, etc.), giving a typical example to illustrate this research direction. Finally, we report on some software simulators and hardware implementations of P systems that have been developed. Keywords Natural computing; biologically-motivated models; membrane computing; P system; symport/antiport; spiking neural P system 1.