A modular high density multi-channel dispenser for micro-array printing

A multi-channel dispenser for micro-array printing has been developed and characterized. We report the fabrication of the dispenser using flexible Polyimide substrate. Polyimide sheets have been dry etched to form /spl mu/-channels. These sheets are sealed with virgin Polyimide sheets by a thermal bonding process. Piezoelectric actuators have been glued onto the channels. 1-dimensional dispenser array has been stacked together to form a 2-dimensional printing array at a nozzle spacing of 500 /spl mu/m. The actuator displacement has been investigated by finite element analysis and by measurements during dispensing for different electrical pulse shapes. The drop formation is recorded with a standard video camera with stroboscope illumination. Droplets of 65 pL have been ejected in parallel at a speed of 2-3 m/s and up to a frequency of 5 KHz.