Triboelectrification of houseflies (Musca domestica L.) walking on synthetic dielectric surfaces

Houseflies (Musca domestica L.) have been found to accumulate significant electrostatic charges when walking on uncharged dielectric surfaces. The number of steps taken was found to determine the amount of charge transferred whereas time, on its own, did not play a significant role. After walking only a short distance, typically 30 cm, flies reached saturation charge. The level of this varied according to the position of the surface in the triboelectric series relative to the fly. The rate of charging (pC/footstep) was directly proportional to the difference between the flyʹs charge and its saturation charge, hence the initial rate of charging for an uncharged fly was directly proportional to the saturation charge. A model has been fitted to the relationship between distance travelled (and hence the number of steps taken) with charge. The reciprocal charge left on the surface has been visualised using photocopier toner.