Patent ID: 7083398

Claim:
A vibrating pumping stage for vacuum pumps, comprising: a supporting base ( 15 ; 15 ′), comprising a silicon wafer; a peripheral rim ( 17 ) formed on said supporting base; a vibrating assembly ( 121 ; 221 ; 321 ) comprising a planar membrane fastened to said supporting base ( 15 ;− 15 ′) and having edge regions, and a side extension ( 125 ) overlapping said peripheral rim defining a first contact area ( 127 ), and a control device ( 21 ) disposed between said supporting base ( 15 ; 15 ′) and said vibrating assembly to make said vibrating assembly vibrate, said control device ( 21 ) being an electrode housed within a cavity ( 13 ) surrounded by said peripheral rim ( 17 ), said electrode comprising a side extension ( 23 ) partly overlapping the peripheral rim defining a second contact area ( 27 ); wherein a variable electric field is applied between said electrode and said vibrating assembly to cause vibration of said vibrating assembly with respect to said supporting base, said electric field generated by a sinusoidal signal, which is applied to said first and second contact areas and said sinusoidal signal having a frequency close to the resonance frequency of said vibrating assembly.