title: Effective Stimulus Parameters for Directed Locomotion in Madagascar Hissing Cockroach Biobot.
abstract: Swarms of insects instrumented with wireless electronic backpacks have previously been proposed for potential use in search and rescue operations. Before deploying such biobot swarms, an effective long-term neural-electric stimulus interface must be established, and the locomotion response to various stimuli quantified. To this end, we studied a variety of pulse types (mono- vs. bipolar; voltage- vs. current-controlled) and shapes (amplitude, frequency, duration) to parameters that are most effective for evoking locomotion along a desired path in the Madagascar hissing cockroach (G. portentosa) in response to antennal and cercal stimulation. We identified bipolar, 2 V, 50 Hz, 0.5 s voltage controlled pulses as being optimal for evoking forward motion and turns in the expected contraversive direction without habituation in ≈50% of test subjects, a substantial increase over ≈10% success rates previously reported. Larger amplitudes for voltage (1-4 V) and current (50-150 μA) pulses generally evoked larger forward walking (15.6-25.6 cm; 3.9-5.6 cm/s) but smaller concomitant turning responses (149 to 80.0 deg; 62.8 to 41.2 deg/s). Thus, the radius of curvature of the initial turn-then-run locomotor response (≈10-25 cm) could be controlled in a graded manner by varying the stimulus amplitude. These findings could be used to help optimize stimulus protocols for swarms of cockroach biobots navigating unknown terrain.
authors: Department of Physics-Engineering, Washington and Lee University, Lexington, Virginia, United States of America.
authors: Jonathan C
authors: JC
authors: Erickson
authors: Department of Physics-Engineering, Washington and Lee University, Lexington, Virginia, United States of America.
authors: María
authors: M
authors: Herrera
authors: Department of Physics-Engineering, Washington and Lee University, Lexington, Virginia, United States of America.
authors: Mauricio
authors: M
authors: Bustamante
authors: Department of Physics-Engineering, Washington and Lee University, Lexington, Virginia, United States of America.
authors: Aristide
authors: A
authors: Shingiro
authors: Department of Physics-Engineering, Washington and Lee University, Lexington, Virginia, United States of America.
authors: Thomas
authors: T
authors: Bowen
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D003058:Cockroaches / Q000502:physiology*; D004558:Electric Stimulation; D006185:Habituation, Psychophysiologic; D008124:Locomotion; D008270:Madagascar; D013997:Time Factors