Accordingly, a surgical portal apparatus for accessing a cavity is provided. Such a material is an electric double layer capacitor material which is used as a material for constituting solid electrolytes 13 and 17 for an electric double layer capacitor 1 and is composed of a metal-salen complex compound. The insertion pipe body has a bottom opening covered by a bottom cover. For that purpose, a fluidic-mechanical safety brake device is used to connect the brake cylinder to the one or more hydraulic lines. The slot receives pressurized gas and establishes a pressure-actuated joint between the interfacing surface portions.