A pressure sensitive sensor is composed of a pair of upper and lower electrodes sheets 1 and 2 disposed oppositely, a spacer 3 interposed between both of the sheets 1 and 2, and adhesives 4 and 5 between these electrode sheets 1 and 2 and spacer 3. A roller is mounted upstream of the print heads and above the process path a predetermined distance. Meltdown of the energy directors during a pressure and ultrasonic welding cycle enable self-leveling of the carbon fiber portions whereby uniform distribution of carbon fiber over the entire cross section of each of the carbon fiber portions of the assembly may be attained. In this invention the part is heated prior to laser scoring to relieve compression forces within the foam layer prior to laser scoring. The comparator, the integrator and the flip-flop are connected in a negative feedback loop such that at steady state the voltage developed by the integrator at the second input of the comparator is substantially equal to the reference voltage.