The diagram below describes a wire imbedding head. I led a small design team that developed this updated version of the system. It replaced an earlier design that relied on pneumatic controls. An important part of this project was analysis and modeling of the imbedding process that helped us avoid mistakes made in the past. One of the important discoveries made in the analysis is that the ultrasonic hammering of the wire not only melted the substrate to facilitate the imbedding, it also put the wire in a plastic state which made it very sensitive to feeding forces.  A simplified description of the process is shown further down the page.

The ultrasonic transducer is a magnetostrictive resonator made of nickel laminates. In a related project I developed a completely new transducer based on a permalloy tube along with a phase-locked generator to drive it.

Wire is applied to a plastic substrate by a computer controlled machine. It is delivered from a spool into the head which feeds it to the substrate surface. On the surface it passes underneath a grooved tip of an ultrasonic stylus. Vibration of the stylus creates heat which melts the substrate beneath the wire. Downward force on the stylus pushes the wire into the softened surface. The plastic quickly hardens as the stylus moves forward, locking the wire in place. Patterns are formed by periodically stopping the head and rotating it to turn the wire in a new direction. At the end of the path, the wire is cut with a small shear near the stylus tip.