In order to attain a compact and simplified feeder assembly 1, the feeder assembly adopts a space receiving a wiring harness 6 to be bend, a sliding member 7 provided in the wiring harness, and a sliding guide to guide the sliding member in the space side. Ripples 24 having depths ranging from 10 to 100 nm are formed with periodicities ranging from 100 to 1000 nm on a stamping tool surface that comes into contact with a workpiece material. At least one electrode is arranged on an electrode carrier and the electrode carrier is arranged on a supporting rod. In addition, arrangements for pressure sensors are provided that mitigate errors from temperature variations and the induced stressstrains.