Sound Modulation in Singing Katydids Using Ionic Polymer-Metal Composites (IPMCs)

Abstract

Many insect families have evolved to produce and detect complex singing patterns for the purposes of mating, display of dominance, predator escape, and other needs. While the mechanisms of sound production by insects have been thoroughly studied, man-machine exploitation of such mechanisms has remained unreported. We therefore describe a method to modulate the frequency spectrum in the chirp call of a singing insect, Gampsocleis gratiosa (Orthoptera: Tettigoniidae), a large katydid indigenous to China and commonly known as Guo Guo or Chinese Bush Cricket. The chirp modulation was achieved through the contact of a ribbon of Ionic Polymer-Metal Composite (IPMC) against wing of the insect. The IPMC effectively served as an actuator when a small DC voltage was applied to the ribbon's faces. By applying a sequential on/off voltage waveform to the IPMC ribbon, the katydid's chirp was modulated in a corresponding manner. This configuration can be used as part of a broader application of using singing insects to harness their acoustic power to produce and propagate machine-induced messages into the acoustic environment.