On polymorphic logical gates in subexcitable chemical medium

Adamatzky, Andrew; De Lacy Costello, Ben; Bull, Larry

Abstract

In a subexcitable light-sensitive Belousov-Zhabotinsky (BZ) chemical medium an asymmetric disturbance causes the formation of localized traveling wave-fragments. Under the right conditions these wave-fragments can conserve their shape and velocity vectors for extended time periods. The size and life span of a fragment depend on the illumination level of the medium. When two or more wave-fragments collide they annihilate or merge into a new wave-fragment. In computer simulations based on the Oregonator model, we demonstrate that the outcomes of inter-fragment collisions can be controlled by varying the illumination level applied to the medium. We interpret these wave-fragments as values of Boolean variables and design collision-based polymorphic logical gates. The gate implements operation XNOR for low illumination, and it acts as NOR gate for high illumination. As a NOR gate is a universal gate, then we are able to demonstrate that a simulated light sensitive BZ medium exhibits computational universality. © 2011 World Scientific Publishing Company.

• Journal Article Type: Article
• Publication Date: Jan 1, 2011
• Deposit Date: Jan 21, 2013
• Publicly Available Date: Feb 17, 2016
• Journal: International Journal of Bifurcation and Chaos
• Print ISSN: 0218-1274
• Electronic ISSN: 1793-6551
• Publisher: World Scientific Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 21
• Issue: 07
• Pages: 1977-1986
• DOI: https://doi.org/10.1142/S0218127411029574
• Keywords: Belousov–Zhabotinsky, logical gates, polymorphic gates
• Public URL: https://uwe-repository.worktribe.com/output/961184
• Publisher URL: http://dx.doi.org/10.1142/S0218127411029574
• Related Public URLs: http://arxiv.org/abs/1007.0034
• Contract Date: Feb 17, 2016