Omnidirectional Walking Microrobot Realized by Thermal Microactuator Arrays
Abstract An omnidirectional mobile microrobot realized by micro-electromechanical system (MEMS) actuator arrays is presented. The microrobot consists of two rigidly connected microcilia array chips, each having an 8 × 8 array of “motion pixels,” which are composed of four orthogonally oriented thermal bimorph actuators. This allows for reliable, accurate motion in three degrees of freedom (x,y,θ) in the plane, a first for a microrobot of this kind. The microrobot is approximately 3cm in length, 1cm in width, 1mm in height, and has a mass of less than half a gram. By varying the input power, actuation frequency and motion gait strategy the velocity of the chip can be precisely controlled. Motion in three degrees of freedom has been demonstrated and a maximum velocity of 635 μm/s and carrying capacity greater than 1.448 g (two 8-pin ICs) has been observed. The microrobot has been characterized extensively and a model for its performance is described.