Laser patterning of thin film sensors on 3-D surfaces

Thinfilm strain sensors applied directly on machine components provide high reliability. However, sensors patterned by standard photolithographic processes are limited to planar surfaces. To overcome these limitations we developed a 3-D capable direct patterning process for NiCr thinfilmsensors based on ultrafast lasers and galvanometer scanners. Our investigations showed that strain sensors with spatial resolution of 30 μm can be patterned on 3-D shaped machine tool components even at extremely tilted surfaces (up to 70°). First machining results and sensor tests indicate that laserthinfilmpatterning enables efficient and automatable production of novel sensor concepts, e.g. for automotive, medical and machine tool applications.