A pressure actuated switching device is made by applying at least a first
layer of fluid conductive polymeric coating material to a surface of a
sheet of green rubber material. The conductive polymeric coating is
solidified to form an electrode, and the sheet of green rubber material
is vulcanized. Two strips of green rubber may be simultaneously processed
and then joined such that the respective layers of conductive coating are
in spaced apart opposing relationship. The conductive polymeric coating
may optionally be formulated with green rubber. Optionally, a blowing
agent may be included in the conductive coating formulation so as to
provide a cellular polymeric foam piezoresistive material from which the
electrode is constructed. The green rubber sheets may be processed by a
continuous rotary method or by a linear method using a clamping press
having opening and closing dies for heating and joining the strips of
green rubber.