Fabrication and feedback control of an articulated microarm

As cancer becomes the No.1 cause of the death in Japan, endoscopic surgery is gaining attentions. In this paper, endoscopical tool to grip and lift the targeted tumor in ESD (endoscopic submucosal dissection) surgery is proposed. This articulated microarm is part of new ESD surgery concept in which two wire-driven microarms (1 times 1 times 25 mm) from the tip of the endoscope help lift the tumor to cut. This research needs to emphasize a new fabrication method of arm which is fabricated by photolithography and electroplating. The microarm is composed of five layers. Individual layers are fabricated separately and assembled together in the end. The microarm uses the elastic deformation of metal to bend (Cu or Phosphor Bronze). It is feedback control with PID using a strain gauge attached to the articulated joint. This technique enabled the further miniaturization of the microarm, but it also comes with a downside. It is difficult to build a 3-dimensional structure. We overcame this problem by proposing an assembly method (STAMP: stacked microassembly process). Electroplated layers are assembled by stacking up on top of each other. This assembly process is feasible to produce multiple microarms at one assembly, thus mass-production with low cost is possible. A strain gauge is attached to the elastic joint as an angle sensor.