A new study hints that computers of the future may have biological components like slime molds that function as logic gates.
Researchers from the University of West England (UWE) in Bristol, UK and the Bauhaus-University Weimar in Germany have successfully constructed logic gates using a slime mold called Physarum polycephalum. This type of slime mold forms colonies using a network of tubes that gradually expands to find the necessary nutrients for survival. These networks can also exhibit responses to certain types of changes in its environment including the presence or absence of light.
The study was conducted by Andrew Adamatzky, a professor of unconventional computing from the UWE and Therese Schubert, a post-media artist from the Bauhaus-University Weimar. The research pair published their findings in the online journal Materials Today.
"The patterns of living, novel computing media require new modes of aesthetic thinking arising from the work of a transdisciplinary team from art and science", said Schubert.
The concept of biological computers has been around for a while now. However, using slime molds as logic gates is a fairly novel and unconventional idea.
"We hope to stimulate discussion and increase awareness of the research through this event, and bring to life many of the complex and changing notions around computing and technology," said Adamatzky. "The research is still in the experimental phase and this dialogue with art provides a way for the public to gain some insight into what we are trying to do."
Physarum is a relatively common type of slime mold found in damp and dark places. Slime molds exhibit a type of vegetative state known as "plasmodium" where the colonial organism becomes active in forming a network of tubes. Using colored dyes, nutrients and salt, the researchers were able to direct the growth of the networks to form logic gates.
"Slime-mould based computing devices are ideal non-silicon complements of conventional processors, novel and emerging computing architectures, robotic controllers and embedded processors for smart structures. A Physarum machine can play the role of universal and general-purpose computer yet also efficiently solve specialized tasks."
The pair also used special dyes with minute beads with fluorescent properties and tiny magnetic nanoparticles to create a "lab-on-a-chip." While the current system is still very simply. The researchers say that created larger networks using the Physarum tubes may be possible. With larger and more complex networks, complex Boolean operations may soon be possible.
"The slime mold tube logical gates display results of logical operations by blocking flow in mechanically stimulated tube fragments and redirecting the flow to output tube fragments. We demonstrate how XOR and NOR gates are constructed," says the study. "We also exemplify circuits of hybrid gates and a memory device. The slime mold based gates are non-electronic, simple and inexpensive, and several gates can be realized simultaneously at sites where protoplasmic tubes merge."
