49.2 Thursday, Jan. 6 Biomechanics of Tactile Sensor for Wall Following and Spatial Mapping MONGEAU, Jean-Michel*; JAYARAM, Kaushik; DEMIR, Alican; SAMPSON, E.G.; COWAN, N.J.; RULL, R.J.; Univ. of California, Berkeley; Univ.of California, Berkeley; Johns Hopkins Univ.; Johns Hopkins Univ.; Johns Hopkins Univ.; Univ. of California, Berkeley firstname.lastname@example.org
Arthropod antennae are multimodal sensors that provide feedback for a variety of tasks. In the cockroach Periplaneta americana, antennal mechanoreceptors mediate locomotor behaviors such as slow exploration, escape, and wall following. During high-speed wall following, cockroaches rely predominantly on mechanosensory structures in the unactuated flagellum. We discovered that mechanical properties of the flagellum simplify control in wall following and may enhance performance in spatial mapping tasks. First, we found that tuned large mechanosensory hairs allow antennae to effectively “stick” to walls by interlocking and enable an antenna to transition to a preferred posture. Second, in ablated antennae and a physical model of the antenna, we tested if medial–lateral biases in stiffness could assist in bending the antenna into an effective position for wall following after gripping a wall. Results do not support the hypothesis that this bias plays an important role for cockroach wall following. Third, in the physical model (Demir et al. SICB 2011), we found that changing an antenna’s proximal-distal stiffness profile affected tactile sensing performance. In these spatial mapping experiments on the physical model, we determined that an antenna with a decreasing stiffness profile from base to tip does more reliable surface contour extractions than one with constant stiffness. Biological measurements are consistent with a nonlinear decreasing stiffness profile similar to that of a conical beam. These mechanical properties of cockroach antennal flagellum inspired the design of a new tactile sensor for wall following and spatial mapping that could be used on a robot. In turn, this robotic antenna will allow us to generate new hypotheses for biology.