A CLUSTER-SIZE NANOFILTER WITH VARIABLE OPENINGS BETWEEN 2 AND 50 NM

A variable size nanoscale particle sieve with openings between 2 and 5 0 nm has been used for determining, selecting, and manipulating the si ze of large liquid helium clusters in the range from 7 x 10(3) to 3 x 10(6) atoms. The variable openings of the sieve are obtained by rotati ng a nanofabricated free-standing transmission grating with a 100 nm p eriod and 50 nm wide slits around an axis parallel to the slits. The n ew nano;sieve can be applied to clusters of various species as well as to large molecules with sizes down to 2 nm. (C) 1998 American Institu te of Physics. [S0021-9606(98)02145-X].