Physarum wires: Self-growing self-repairing smart wires made from slime mould

We report experimental laboratory studies on developing conductive pathways, or wires, using protoplasmic tubes of plasmodium of acellular slime mould Physarum polycephalum. Given two pins to be connected by a wire, we place a piece of slime mould on one pin and an attractant on another pin. Physarum propagates towards the attract and thus connects the pins with a protoplasmic tube. A protoplasmic tube is conductive, can survive substantial over-voltage and can be used to transfer electrical current to lightning and actuating devices. In experiments we show how to route Physarum wires with chemoattractants and electrical fields. We demonstrate that Physarum wire can be grown on almost bare breadboards and on top of electronic circuits. The Physarum wires can be insulated with a silicon oil without loss of functionality. We show that a Physarum wire self-heals: end of a cut wire merge together and restore the conductive pathway in several hours after being cut. Results presented will be used in future designs of self-growing wetware circuits and devices, and integration of slime mould electronics into unconventional bio-hybrid systems.