the cathode to the anode completes the electric circuit forming an exiting plasma flame plasma temperatures can be relatively high e g 15 000k for a conventional dc torch operating at 40 kw the ceramic material being deposited onto a substrate is supplied in powder form the powder is introduced into the plasma flame the powder particles are accelerated and melted in the flame on a high speed path to the substrate where they impact and undergo rapid solidification variations may exist in the general plasma spray process and the process may be adapted to a variety of deposition materials another direct write technique is laser chemical vapor deposition lcvd which is a thermal technique for film growth a laser is employed as an activator of a precursor for the ceramic that is photolyzed pyrolyzed or vibrationally rotationally excited the technique can be used to form complex structures on a substrate by u201c mass addition u201d the material deposition can be carried out under computerized motion control as in other direct write processes another common direct write technique is based on ink jet techniques various ink jet systems can be employed e g continuous mode systems and demand mode e g impulse systems within the latter category there are various types of impulse systems as well e g piezoelectric systems and thermal impulse systems the electronic control mechanisms for ink jet systems are also known in the art various computer control systems can be employed e g using.