▁now ▁allows ▁consum ers ▁to ▁create ▁custom ▁cases ▁for ▁their ▁mobile ▁ph ones . ▁N ok ia ▁has ▁released ▁the ▁ 3 D ▁designs ▁for ▁its ▁case ▁so ▁that ▁own ers ▁can ▁custom ize ▁their ▁own ▁case ▁and ▁have ▁it ▁ 3 D ▁printed . ▁ ▁Rap id ▁manufact uring ▁ ▁Adv ances ▁in ▁R P ▁technology ▁have ▁introduced ▁materials ▁that ▁are ▁appropriate ▁for ▁final ▁manufact ure , ▁which ▁has ▁in ▁turn ▁introduced ▁the ▁possibility ▁of ▁directly ▁manufact uring ▁finished ▁components . ▁One ▁advantage ▁of ▁ 3 D ▁printing ▁for ▁rapid ▁manufact uring ▁lies ▁in ▁the ▁relatively ▁in exp ensive ▁production ▁of ▁small ▁numbers ▁of ▁parts . ▁ ▁Rap id ▁manufact uring ▁is ▁a ▁new ▁method ▁of ▁manufact uring ▁and ▁many ▁of ▁its ▁processes ▁remain ▁un pro ven . ▁ 3 D ▁printing ▁is ▁now ▁entering ▁the ▁field ▁of ▁rapid ▁manufact uring ▁and ▁was ▁identified ▁as ▁a ▁" next ▁level " ▁technology ▁by ▁many ▁exper ts ▁in ▁a ▁ 2 0 0 9 ▁report . ▁One ▁of ▁the ▁most ▁prom ising ▁processes ▁looks ▁to ▁be ▁the ▁adaptation ▁of ▁select ive ▁las er ▁s inter ing ▁( S LS ), ▁or ▁direct ▁metal ▁las er ▁s inter ing ▁( D ML S ) ▁some ▁of ▁the ▁better - est ab lished ▁rapid ▁pro tot yp ing ▁methods . ▁, ▁however , ▁these ▁techniques ▁were ▁still ▁very ▁much ▁in ▁their ▁inf ancy , ▁with ▁many ▁obst acles ▁to ▁be ▁overcome ▁before ▁R M ▁could ▁be ▁considered ▁a ▁real istic ▁manufact uring ▁method . ▁ ▁There