The fabrication of a micro injector actuated by boiling and/or electrolysis

This paper presents the fabrication of a micro injector which can be attached to the end of a micro intravascular endoscope for drug injection. The injector consists of a drug chamber and an actuator chamber which are separated by a silicone rubber membrane. The injector discharges some liquid drug less than one microliter through a nozzle. The injector is fabricated by anisotropic etch, boron deposition and metal evaporation. The silicone membrane is actuated by the bubbles which are generated by boiling or the electrolysis of the electrolyte in the actuator chamber. The deflection of the membrane for the each method has been measured. Also, the injection volume has been measured from the video images captured during the electrolysis of water or NaCl solution. The experimental results show that the actuation by the electrolysis of NaCl solution is effective