PIEZOELECTRIC-DROP-ON-DEMAND TECHNOLOGY AND CLEANING OF CAPILLARIES

摘要

A method and apparatus for cleaning the interior of capillary tubes (62) used to dispense 1 to 100 micron diameter liquid droplets by a piezoelectric transducer (60) surrounding each capillary tube. Magnetic particles are aspirated into the capillary tubes and moved by an exterior magnet to cause deposits on the interior walls to be dislodged and subsequently discharged from the capillary tube. In a preferred embodiment, the magnetic particles are coated with a material capable of binding such deposits.