Design and performance of a micro-sized biomorphic compound eye with a scanning retina

In this paper, we propose a design of a biomorphic micro visual sensor equipped with a mechanical scanning system. The sensor is inspired by the structure of the fly's compound eye, which was found to possess a unique muscle and tendon actuation system for its scanning retina. The improvement in micro-opto-electro-mechanical systems encourages the design of reliable, efficient, and integrated smart visual sensors for robotic applications, in particular, for the autonomous visually guided navigation of mobile robots. We have verified the effect of retinal scanning for a robotic visual system through the construction of a large-scale prototype at the millimeter scale. The performance of a newly fabricated microelectromechanical system prototype whose size approaches the order of the insects' compound eyes is then evaluated in comparison with that of the large-scale prototype. The micro-sized visual sensor is composed of a scanning microlens array (120 mu m in lens diameter) and a photo-diode array. The actuation of the microlens array induces a rotation of the visual axes. According to the principle of retinal scanning, the micro-sensor is able to retrieve the local angular velocity with enhanced reliability. [445].