  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.
