The present invention provides a photovoltaic device comprising metal and a poly layer that incorporates a suitable amount of 1H-benzotriazole. A gold-plated female terminal fitting 10Au is formed by attaching a shell 20 to a terminal main body 11, and a tin-plated female terminal fitting 10Sn is formed by attaching a shell 30 to the same kind of terminal main body 11 as used for the gold-plated female terminal fitting. The buffer facilitates the transducer to operate within a predetermined mechanical loading range to allow the system to provide electrical energy. The devices utilize fluid impermeable outer surfaces and distributed pressure to achieve tamponade and hemostasis, primarily by exertion of pressure. The inner walls of the socket are flat to fit snugly against corresponding flat surfaces of the valve to provide more positive engagement of the valve.