Abstract
This paper reports the design and fabrication process of an exoskeletal microarm. The research of the microarm is part of a new concept of endoscopes designed for endoscopic submucosal dissection (ESD) operation. This novel ESD endoscope has two suction grippers to hold the lesion skin, and a cautery knife to cut. The grippers and cautery knife need to be manipulated at the end of the endoscope, thus a powerful yet small arm is needed. We focused on the shape memory alloy (SMA) for its high work output unit volume and its high power/mass ratio. However, the previously researched SMA actuated microarm bends by deforming its entire body. This mechanism makes it difficult to calculate the position of its end tip, necessary for the control of the grippers and the knife. Here, we propose an exoskeletal microarm. Polydimethylsiloxane (PDMS) elastomer is used to fabricate the microarm using a photolithography technique. The microarm is coated with hardening epoxy polymer, leaving only the joint part of the microarm uncoated. By placing an angle sensor at the joint, we are able to calculate the position of the microarm end. Selection and placement of the angle sensor and other parts of the new ESD endoscope is to be studied in the future.
