Development of an active reflector using a liquid metal droplet and application of endoscope to increase viewing angle

In this paper, we developed an active reflecting system using a liquid metal (i.e., Galinstan) droplet and successfully applied to the endoscope. The system can selectively enlarge viewing angle. It can greatly increase the efficiency of the operation for the operator or constructor when using an endoscope for surgery or narrow pipeline observation. We use Continuous electrowetting (CEW) effect to drive the Galinstan droplet even at low voltage (-several V). To increase the portability, we fabricated a small gun-shaped controller and successfully operated active reflector. Finally, we confirmed that the front and side view of narrow tube inside can be selectively observed by switching with this system.