Biologically inspired robots using Smart Composite Microstructures

Abstract

Various biologically inspired small scale robots are built with endoskeleton structures. Generally, endoskeletons consist of rotational joints and rigid links. For millimeter scale robots, endoskeletons should be scalable and easy to manufacture. Layers of composite materials and polymer film can be fabricated into small scale joints and link structures as seen in fig. 1. The structures are called SCM (Smart Composite Microstructures) [1]. These structures have many advantages in small scale robot structures in aspect of friction and manufacturing simplicity. We expand the structure with SMA spring actuator for actuation of small components. In this video, we show three robot prototypes using SCM. The first robot is a fully foldable robot using torsional spring type SMA actuator. As seen in fig. 2, three segments of plate structures can be folded into a compact cube shape. The Second robot is Omegabot: Inchworm inspired robot [3]. It crawls with two anchors gripping the ground alternatively by making its body into an omega shape. This simple locomotion is a suitable moving mechanism for small scale robots. The Omegabot produces motions of crawling, climbing, and steering with tethered power and control. The third robot is a flea inspired robot. The flea can jump more than 130 times of its body length with its body length just below 1mm. The flea uses a torque reversal mechanism which enables storing large amount of energy and releasing it with a small amount of force. This mechanism is simple and efficient, which makes it a good mechanism for small jumping robots. The current prototype of the flea inspired robot jumps 64cm high, which is about 30 times of the robot body length. The SCM enabled these novel small scale robots, and has a potential to enable various small scale robots.