Development Of A Soft-body Peristaltic Micro-robot

The evolutionary process over hundreds of millions of years has endowed the animals with high efficiency of locomotion, adaptation to the specific different environments and some extent of intelligence. Development some kinds of bio-robots by replication of the locomotion inspired by the animal analogues, is a hot field in robotics with combining the roboticist, biologist, intelligent engineer and so on. In this thesis, different types of locomotion especially on semi-solid and soft substrate existing in low level animal have been reviewed. However, because of high complexity and super integration of actuation, sensing and controlling mechanism, it extremely difficult to fully replicate even one of simplest monocyte. The biomimetic degree has to be trade-off with the real technology limitation. Finally, peristalsis was chose to imitate and earthworm is the animal counterpart of the biomimetic micro-robot because of the simple locomotion mechanism and highly module structure.The research on peristalsis robotic system (e.g. artificial snake) initiated in last century. These systems are usually built with rigid modules which composed by motors and relevant components. With controlling rotation of every module to left and right, they conducted the body wave along the body from head to tail, thus imitating the biological peristalsis. But the rigidity of the body hindered their adaptive ability because the compliant bodies of biological peristalsis system obviously contribute to controlling and stability. Further more, it is some difficulties to reduce the size because of the mechanical structure and motor integration. That's why we try to build up a soft-body micro peristalsis system in this thesis.The robotic replication of a crawling earthworm should not only consider the locomotion mechanism, but also perception system and neural control, together with the enabling technologies to implement such a type of imitation. In actually, the locomotion mechanism, perception system and controlling are harmonized fusion in biological systems;and thus, they possess marvelously high adaptive ability, efficiency and intelligence.It is important to have the smart structure design, the selection of proper actuation mechanism, sensing element and the integration method. Following the biological paradigm, we realized miniaturized smart structure which could have the ability of contraction/elongation. It is also important to develop proper sensors not only on-bench application, but also for intimately integrated with miniaturized mobile structures, and able to perceive both surrounding environment and internal status of these mobile structures. Four flexible PVDF sensors have been embedded in each miniaturized mobile structure with innovation fabrication method (Molding-Embedding-Remolding, MER) which is evolved from one of life-like manufacture technology-SDM (Shape-Deposition-Manufacturing, invented by Stanford University).In this thesis, 4-module soft-body sensorised earthworm-like micro-robot has been developed. The micro-robot is able to achieve the similar locomotion frequency and speed as the animal counterpart. The experiments showing the developed biomimetic sensing system is able to detect the external contact and internal actuation of the micro-robot, thus mimicking exteroception and propriocention of animal counterpart and being useful for optimum controlling strategy with modifing the CPGs. Hopefully, the soft-body smart crawling earthworm micro-robot constitutes a platform improving the knowledge of mechanism which regulates the motion and perception abilities of lower animal forms. It is helpful for finally developing adaptable and smart micro peristalsis robotic systems.