Patent ID: 6852545

Claim:
A method of operating a micropipette to expel a sample solution from an injection port of the micropipette, comprising the steps of: providing a micropipette comprising (i) at least one substrate, (ii) an inlet port through which a sample solution is delivered from the outside, formed in or on said at least one substrate, (iii) a cavity into which a sample solution is poured and which is filled with the sample solution, said cavity having a length of about 1-5 mm, a width of about 0.1-1 mm, a depth of about 0.1-0.5 mm, and a plane passing through a center of said cavity when viewed in the depth direction, (iv) an introduction hole between said inlet port and said cavity at a position at or below said plane, (v) an injection port for expelling the sample solution formed in communication with said cavity, and (vi) a piezoelectric/electrostrictive element provided on at least one wall of the substrate; filling said cavity with a displacement liquid; driving said piezoelectric/electrostrictive element to expel the displacement liquid out of said cavity through said injection port and simultaneously replace the displacement liquid in said cavity with a sample solution; and continuing driving said piezoelectric/electrostrictive element to expel the sample solution from said injection port.