Fabrication and in vitro test of a microsyringe

This paper presents the fabrication of a microsyringe, which can be attache d to the end of a microintravascular endoscope for drug injection. The syri nge consists of a drug chamber and an actuator chamber, which are separated by a silicone rubber membrane. The drug chamber is filled with liquid drug by the membrane actuation caused by the vaporization and condensation of t he working liquid in the actuator chamber. The liquid drug, less than 1 mu l, is ejected through a nozzle by the bubbles generated from the electrolys is of the working liquid. The syringe is fabricated by micromachining. The deflection of membrane for the each method has been measured. The liquid ej ection volume has been measured from the video images captured during the e lectrolysis of the electrolyte. The average speed at nozzle from 0.1 to 1 s is about 0.14 m/s. Further, the successful operation of the microsyringe u nder the normal blood pressure was verified. (C) 2000 Elsevier Science S.A. All rights reserved.