Development and Characterization of Multi-Material Printing of the Drop-on-Demand (DoD) System

Abstract

The aim of this project is to realize the possibility of fabricating an applicable multi-material product through means of Drop on Demand (DoD) dispensing, using different type of print heads with different methods of actuation within a single dispensing system. Other than compatibility issues and the necessary modifications to the hardware and software of an original DoD system, much considerations are also given to the sequence of dispensing for the different dispensers, the use of suitable substrate, the load bearing capability of the printed materials and the different curing time for each type of dispensers; all of which can directly or indirectly affect the performance of the multi-material products. Characterization has been done for two different print heads, namely, the piezo-actuated print head and the micro-valve print head in order to obtain the optimal dispensing parameters. A study of drop formation upon impact on various substrates and the effect of curing temperature on drop formation have also been done. Finally, using the most suitable substrate, a multiple layered capacitor consisting of overlapping poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT: PSS) films as the conductive layer and poly(4-vinyl-phenol) (PVP) is fabricated using the Multi-material, Multi-nozzle DoD system with various tests done on it to verify its functionality.