To provide a probe coil for an NMR apparatus which can transmit and receive high frequency radio waves with improved Q-factor and SN ratio. The external conductor comprises a base area bounded by one or more side walls thereby forming an external conductor housing with an internal space and an opening opposite the base area. The passive fibers of each fiber component have respective protective coatings spaced from one another and each covering the cladding of the fibers. Upon movement of the wire, the treatment device operates. Also described are processes for making and using the printheads as well as processes for forming patterns and images on a substrate including jetting inkjet inks or jettable materials using a printhead for inkjet printing that has been modified with a self-assembly monolayer.