Design of a micro-scale magnetostrictive asymmetric thin film bimorph (μMAB) microrobot

This paper presents the design, analysis, and performance results for a mobile microrobot that was designed for competing in the 2010 NIST Mobile Microrobot Challenge. Inspired by a crab-like microrobot driven by pulsating cardiomyocyte cells, an asymmetrically dimensioned magnetostrictive thin film bimorph microrobot has been designed. Utilizing the magnetostrictive principle, different bending and blocking forces occur under the robot's feet due to the in-plane strain generated in the bimorphs by the application of external magnetic fields in the workspace of the microrobot. The differences in the resulting frictional forces drive the movement of the robot body. To calculate and simulate whether the feet of the robot can generate enough force for locomotion, the design was abstracted and translated into a piezoelectric cantilever FEM model. The results are consistent with the magnetostrictive theoretical equations. Microrobot fabrication and test-bed development based on this analysis is shown along with experimental results validating this approach. Finally, a discussion of the performance results and recommendations for future improvements are provided.