ARRIpede: A stick-slip micro crawler/conveyor robot constructed via 2 ½D MEMS assembly
ABSTRACT Recent advances in 2frac12D and 3D hybrid microassembly using MEMS snap fasteners and die-level bonding for interconnects, makes possible the miniaturization of exciting new small robots configured for various functions, such as flying, crawling, or jumping. ARRIpede is one example of a ldquodie-sizerdquo crawling microrobot constructed by assembly and die stacking. It consists of a MEMS die ldquobodyrdquo, in-plane electrothermal actuators, vertically assembled legs, and an electronic ldquobackpackrdquo to generate the necessary gait sequence. The robot has been designed using a stick-slip simulation model for a target volume of 1.5 cm times 1.5 cm times 0.5 cm, a 3.8 g mass, and velocities up to 3 mm/s. Even though work remains to be completed in packaging the robot, we demonstrated that the robot design is sound by experimentally evaluating the leg actuation force, the payload carrying capacity, the power consumption, and the manipulation ability of an inverted ARRIpede prototype. A configuration that carries a payload approximately equal to its own weight shows excellent steering ability. A reasonable match between simulations and experiments is noted, for example, when the legs are actuated at 45 Hz and 10 V, the crawling velocity of the microrobot was experimentally measured to be 0.84 mm/s or 18.7 mum per step, while the simulated leg displacement was 18.5 mum per step. The prototyped ldquoconveyorrdquo mode had a maximum measured linear velocity in excess of 1.5 mm/s, while consuming approximately 500 mW of power. We expect that for achieving lower speeds, such as 0.15 mm/s, the power consumption can be reduced to a few mW, enabling untethered operation.
Conference Proceeding: A ciliary based 8-legged walking micro robot using cast IPMC actuators[show abstract] [hide abstract]
ABSTRACT: We have proposed a prototype model of walking micro robot using IPMC (Ionic Polymer Metal Composite) actuators. The stiffness of IPMC actuator is a key parameter to implement a walking robot. Therefore, the casting process is developed to increase the stiffness of the actuator by controlling thickness of ion-exchange polymer film. The process of fabricating a solid film front liquid state of ion-exchange polymer is difficult since any process parameter and handling material are not disclosed and has to be set by trial and error. The bending characteristics and generative tip force of IPMC actuator under variation of thickness and length of the actuator and voltage input are investigated. Also, mechanical model is derived to predict the generative tip force and displacement of IPMC actuator according to the variation of thickness. With cast film based IPMC actuators, a ciliary type 8-legged micro robot, which can be operated in aqueous surroundings like inside of human body, is constructed and tested. The robot shows good reliability and can reach up to 17 mm/min in speed.Robotics and Automation, 2003. Proceedings. ICRA '03. IEEE International Conference on; 10/2003
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ABSTRACT: One of the major issues enduring with micro-scale mechanics has been to design high fidelity miniature machines capable of performing complex operations. Though achieved in some proportion through conventional in-plane and out-of-plane designs, the efficacy of such micro-electromechanical systems (MEMS) structures is highly limited due to complicate fabrication and inadequate robustness. On the other hand, the use of precise robots to assemble MEMS parts of comparatively simpler design to build 3D micromechanical structures has recently emerged as a viable approach. Such modular assemblies of microscale parts typically utilize minimum energy connectors that are multifunctional, e.g., mechanical, electrical etc. The μ<sup>3</sup> is a 3D microassembly station consisting of 19 DOF arranged into 3 micromanipulators, with additional microgrippers and stereo microscope vision. The platform is capable of motion resolutions of 3nm and is small enough to be used inside of a scanning electron microscope (SEM) for nano-manipulation. In this paper we discuss how systematic identification and calibration of the station, combined with appropriate part connector designs can lead to multi-degree of freedom active MEMS robots assembled on a waferRobotics and Automation, 2007 IEEE International Conference on; 05/2007