A piezoresistive sensor for pressure monitoring at inkjet nozzle

• Published in: 2010 IEEE Sensors pp. 2093 - 2096
• Main Authors: Wei, Jia, Sarro, Pasqualina M., Duc, Trinh Chu
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.11.2010
• Subjects: Biomembranes; Electrical resistance measurement; Orifices; Piezoresistance; Semiconductor device measurement; Stress
• ISBN: 9781424481705; 1424481708
• ISSN: 1930-0395; 2168-9229
• DOI: 10.1109/ICSENS.2010.5690353

This paper presents a MEMS piezoresistive sensor for monitoring the fluidic pressure at the nozzle of an inkjet during droplet generation. The device consists of a sensing membrane (150 μm wide and 1 μm thick) with a nozzle orifice (20 μm in diameter), and piezo-resistors placed around. The pressure information is useful in detecting missing droplets and estimating the size of the generated droplets. The device is fabricated on SOI wafers with an IC-compatible process. A resistance variation of 8.7% is measured with a 1 × 10 5 Pa applied pressure. The sensitivity is 3.9 × 10 -7 V/Pa in a Wheatstone bridge configuration with 1 V supply voltage. The detected pressure signal can be used to implement a close-loop control to replace the open-loop control in most current commercial inkjet printheads, for better volume precision and system reliability.