Many processing steps in the manufacturing of flexible membrane switches require solution processing. Inkjet printing is a facile method for depositing solutions into patterned thin films. Piezoelectric inkjet printing is an open controllable process, thereby enabling the use of a variety of fluids deposited on a variety of substrates to produce the desired product. We have taken several steps back from device manufacturing and worked out the details of inkjet printing of conductive, three dimensional dielectric and adhesive components. Each individual layer has its own set of requirements on how the fluid jet from the piezo-based printhead and how it perform on the substrate to give the desired results to produce a functioning device. In addition, it can be demonstrated that these individual layers are applicable to a variety of other products utilizing digital printing technology. In these applications they are applicable for discrete unique devices or mass production of thousands of devices using the same digital fabrication technology. We will show the successful thin film patterning of these fluids, and we will also show their electrical and physical properties. Finally, we will show other patterned thin films of relevant materials including other conductive nanoparticle inks and dielectrics used in photovoltaic and display applications, carbon nanotubes used as transparent conductors, conjugated polymers used in the active layer and quantum dots, band gap acceptor materials that also function in non-white light environments. Finally, this talk will discuss the impact of inkjet printing on printed electronics and highlight the research efforts of leaders in this field.
Darrell Etter, "Membrane Keypad Printing Using Only Inkjet Technology" in Proc. IS&T Int'l Conf. on Digital Printing Technologies and Digital Fabrication (NIP27), 2011, pp 351 - 355, https://doi.org/10.2352/ISSN.2169-4451.2011.27.1.art00091_1