Omnidirectional Walking Microrobot Realized by Thermal Microactuator Arrays

An omnidirectional mobile microrobot realized by microelectromechanical 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.