Fabrication of a Pinching Mechanism with a Cylinder type Gas-Liquid Phase-Change Actuators

In this paper，we describe the fabrication of a pinching mechanism with a cylinder type gas-liquid phase-change actuator，Pneumatic actuator is used for endoscopic surgery support robot．However pneumatic actuator have some faults．Its peripheral equipment is large and makes oscillation and electromagnetic noise．These adversely affect medical equipments．We think that new actuator which does not have those faults is necessary．We suggest a gas-liquid phase change actuator．It is an actuator which big power is got from in the small size．And it can work only with DC power supply such as dry cells．Its device is small and has a small influence to give medical equipments．In this study，we aim to design，compare and examine three pinching mechanisms for actuators using the principle of leverage and investigate their characteristics．We created a cylinder-type actuator that can move a piston using a gas-liquid phase change．The actuator was used to operate three pinching mechanisms with different actuator arm size ratios，and the closing speed and pinching force were measured．As a result，it was found that the longer the driving arm, the stronger the force，and the longer the driven arm，the better the responsiveness．From this，it was thought that the design could be determined based on the required performance and arm ratio，so that the right material could be designed for the right place．