▁by ▁a ▁C AD ▁system ▁which ▁interpol ates ▁solid ▁objects ▁into ▁a ▁set ▁of ▁tracks , ▁thus ▁producing ▁the ▁desired ▁part ▁at ▁the ▁end ▁of ▁the ▁traject ory . ▁ ▁A ▁great ▁deal ▁of ▁research ▁is ▁now ▁being ▁concentr ated ▁on ▁developing ▁automatic ▁las er ▁cl adding ▁machines . ▁ ▁Many ▁of ▁the ▁process ▁parameters ▁must ▁be ▁manually ▁set , ▁such ▁as ▁las er ▁power , ▁las er ▁foc al ▁point , ▁substr ate ▁velocity , ▁pow der ▁injection ▁rate , ▁etc ., ▁and ▁thus ▁require ▁the ▁attention ▁of ▁a ▁special ized ▁techn ician ▁to ▁ensure ▁proper ▁results . ▁ ▁However , ▁many ▁groups ▁are ▁foc using ▁their ▁attention ▁on ▁developing ▁sens ors ▁to ▁measure ▁the ▁process ▁online . ▁ ▁Such ▁sens ors ▁monitor ▁the ▁cl ad ' s ▁geometry ▁( height ▁and ▁width ▁of ▁depos ited ▁track ), ▁met all urg ical ▁properties ▁( such ▁as ▁the ▁rate ▁of ▁solid ification , ▁and ▁hence ▁the ▁final ▁micro structure ), ▁and ▁temperature ▁information ▁of ▁both ▁the ▁immediate ▁m elt ▁pool ▁and ▁its ▁surrounding ▁areas . ▁ ▁With ▁such ▁sens ors , ▁control ▁strateg ies ▁are ▁being ▁designed ▁such ▁that ▁constant ▁observation ▁from ▁a ▁techn ician ▁is ▁no ▁longer ▁required ▁to ▁produce ▁a ▁final ▁product . ▁ ▁Further ▁research ▁has ▁been ▁directed ▁to ▁forward ▁processing ▁where ▁system ▁parameters ▁are ▁developed ▁around ▁specific ▁met all urg ical ▁properties ▁for ▁user ▁defined ▁applications ▁( such ▁as ▁micro structure , ▁internal ▁str esses , ▁dil ution ▁zone ▁grad ients , ▁and ▁cl ad ▁contact ▁angle ). ▁