This paper explores the use of mechanical redundancy to enhance robustness to leg failures in miniature ambulatory robots. Graceful degradation, rather than immediate catastrophic failure, is exhibited experimentally in 10-20 leg centipede-inspired millirobots as legs are removed without altering the gait, using speed and radius of curvature as performance metrics. Static stability retention is examined as a function of the nominal number of legs, and for cases where static stability is lost, two gait options are tested. The effect of location of missing legs on performance is also described.

The design and modeling of a segmented myriapod millirobot with a compliant body is presented. A dynamic model is used to demonstrate how body undulations can result from only varying the phase difference in the stance change between adjacent segments - even with passive intersegmental connections - and how these gaits affect locomotion. Different gaits are demonstrated experimentally in a 20-leg, 2.2 gram millirobot, and the resulting motion is compared to that predicted by the simulation. Both simulation and experiments show that undulatory gaits can increase the average speed of straight-line locomotion as compared to non-undulatory gaits for the same stepping frequency. The model and the millirobot can be used concurrently with biological studies to understand aspects of myriapod locomotion. This robot is also a useful tool to gain insight into how flexibility can be introduced into robots at this scale to enhance locomotion.

The kinematic design of a multi-segment ambulatory microrobot inspired by centipedes is presented. The kinematics of five repeated segments joined by a flexible backbone of rigid links and flexures are described and simulated. The kinematic model was used to guide the design of an individual two degree of freedom segment, which was fabricated using the Smart Composite Microstructures process. Testing and analysis of a suspended segment displayed motion similar to that predicted by the model. Multiple segments can be joined to a flexible backbone to create a multi-segment structure capable of a variety of gaits. Due to its modular, multi-legged, and compact design, this robot has the potential to serve as a platform for swarm robotics applications, advance control techniques for ambulatory systems, and inspire batch fabrication of microrobots.