Analysis and design approach to inchworm robotic insects

An inchworm robotic insect is presented that can displace on a smooth horizontal surface. It consists of a piezoelectric unimorph and two custom-designed limbs. A two-module lumped-parameter model is formulated to assist in the design/analysis process. The geometry of deformation is analyzed first by superimposing the unimorph´s elastic deformation to a rigid-body rotation around the limb/ground contact point A geometry configuration is thus identified that maximizes the horizontal displacement of the robot over one motion´s cycle. The dynamic module allows simple evaluation of the ground reaction forces and horizontal velocity of the robot´s center of gravity. A prototype inchworm robotic insect was designed whose behavior exhibited good agreement with theoretical predictions