A method is disclosed of connecting first and second electrical connectors each having a plurality of aligned straight pins complementary to corresponding pins of the other connector, the pins of each pair of complementary pins being designed to engage coaxially one within the other. The method involves applying to the paper an aqueous solution comprising 0. The articulating means can comprise a portion of the shaft which is rotatable about a first axis in order to articulate the end effector about a second axis. The opening extends in the first direction to pass the light reflected by the target.