Abstract-In this p a p e r we describe t w o new t y p e s of' t r a n s d u c e r assemblies fabricated f r o m polyimide films w i t h photolithography t h a t use a polyimide micromachine ( M E M S ) a c t u a t o r t o mechanically scan a n u l t r a s o u n d beam. F o r w a r d viewing t r a n s d u c e r s pivoting on cantilever hinges a n d side scanning t r a n s d u c e r s tilting o n torsion hinges were fabricated o n polyimide s u b s t r a t e s w i t h t a b l e s 1.125 m m a n d 2.25 m m wide. PZT t r a n s d u c e r s fabricated on t h e s e t a b l e s o p e r a t i n g at 20 M H z a n d 30 M H z yielded insertion losses of 20-26 d B a n d fractional b a n d w i d t h s of
34-49%.T h e t r a n s d u c e r assemblies driven by M E M S act u a t o r s produced s e c t o r scans of 45-60° in air a t resonant frequencies of 32 t o 90 Hz a n d sector scans in fluid of 6-8 O . Real t i m e images of wire p h a n t o m s were o b t a i n e d using a single channel imaging system based o n a personal c o m p u t e r platform w i t h L a b V I E W ( N a t i o n a l I n s t r u m e n t s Corp., A u s t i n , TX) software.