Piezoelectric shear mode drop-on-demand inkjet actuator
2002 (English)In: Sensors and Actuators A-Physical, ISSN 0924-4247, Vol. 101, no 3, 371-382 p.Article in journal (Refereed) Published
We report on comprehensive characterization of piezoelectric shear mode inkjet actuators micromachined into bulk Pb(Zr0.53Ti0.47)O-3 (PZT) ceramics. The paper starts with an overview of different drop-on-demand inkjet systems, whereas the main attention is then turned on particular Xaar-type piezoelectric shear mode inkjet printheads. They are an example of complex microelectromechanical system (MEMS) and comprise a ferroelectric array of 128 active ink channels (75 mum wide and 360 mum deep). Detailed information about fabrication process and principles of operation are given. Since each actuating wall of 128 channels is a piezoelectric capacitor metallized from both sides to be animated by electric pulse, electrical properties of channel walls (CWs) are easy to test and serve as a fingerprint of actuator performance in the virgin state as well as after high voltage/elevated temperature heavy duties. We present several techniques to control manufacturing process and fatigue effects. So, continuous wave and pulsed spectroscopy and hysteresis P-E loop tracing showed that compared to a virgin PZT ceramics state, dielectric permittivity (epsilon') was reduced three times, the loss factor (tan delta) increased from initial 4.8 to 6.6%, remnant polarization decreased by 43%, coercive field increased by 38%, whereas Curie temperature increased from 508 to 560 K after 90,000 cycles of ferroelectric hysteresis P-E loop tracing at 50 Hz at electric field of 88.5 kV/cm. Heat treatment also results in PZT ceramics degradation: appreciable reduction of the coupling coefficient (k(15)) and the degradation of inkjet performance were revealed by optical stroboscope technique: 8.7 and 14% reduction of drop velocity and volume in electrically fatigued actuator, 2.5% reduction of drop velocity and unchanged drop volume in temperature-treated actuators.
Place, publisher, year, edition, pages
2002. Vol. 101, no 3, 371-382 p.
microelectromechanical system (MEMS), actuator, shear mode, inkjet printhead, piezoelectric ceramics, pulsed spectroscopy, acoustic resonance, fatigue
IdentifiersURN: urn:nbn:se:kth:diva-21995ISI: 000178838900014OAI: oai:DiVA.org:kth-21995DiVA: diva2:340693
QC 201005252010-08-102010-08-10Bibliographically approved