International Journal of Mechanical Sciences 46 (2004) 181–199 Numerical and experimental comparisons of mass transport rate in a piezoelectric drop-on-demand inkjet print head Dong-Youn Shin a ; * , Paul Grassia b , Brian Derby a a Manchester Materials Science Centre, UMIST, Grosvenor Street, Manchester M1 7HS, UK b Department of Chemical Engineering, UMIST, P.O. Box 88, Manchester M60 1QD, UK Received 30 April 2003; accepted 17 March 2004 Abstract The analysis of oscillatory uid ow in a piezoelectric drop-on-demand cylindrical inkjet print head has traditionally been implemented by computationally expensive numerical methods although the print head itself consists of simple shaped components such as a cylindrical tube surrounded by a piezoelectric actuator, and a conical tube for the nozzle part. In a preliminary design stage, it is strongly desirable to save time and eort when simulating the impact of the design on the drop generation. For this purpose, approximate analytic solutions, which describe the uid motion in an inkjet print head, are developed. Axial velocity history is fed back to a further drop formation simulation with a simplied 1D FDM model. The strengths and weaknesses of the 1D approach are identied. Despite the compactness of the present approach, the results show encouraging agreement of mass transport rate with experimental data. ? 2004 Elsevier Ltd. All rights reserved. Keywords: Drop-on-demand; Drop formation; Mass transport rate 1. Introduction Since the advent of the inkjet technology, its application has been extended from conventional graphics printing to newer applications. Kobayashi et al. [1] demonstrated the capability of fabricating light-emitting polymer displays. Cooley et al. [2], and, Danzebrink and Aegerter [3] have applied the key feature of inkjet technology, non-contact dispensing on the scale of nano- to pico-litre, to biological applications, chemical analysis, optical elements, sensors and electrical interconnections. ∗ Corresponding author. Tel.: +44-161-200-3583; fax: +44-161-200-3586. E-mail addresses: d.shin@umist.ac.uk (D.-Y. Shin), paul.grassia@umist.ac.uk (P. Grassia), brian.derby@umist.ac.uk (B. Derby). 0020-7403/$ - see front matter ? 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.ijmecsci.2004.03.008