Fundamental study on fabrication of flexible devices using roll to roll printing technology

In recent years, as a manufacturing technology of a flexible device, a printed electronics technology attracts attention. However, mass production of flexible devices is required, and improvement of mass productivity is required. Therefore, in order to improve mass productivity, an installation method for introducing into a Roll to Roll system in which a web, which is a thin continuous medium, is supported and transported using a friction force with a roller was studied. However, there are many problems in both the Printed Electronics technology and the Roll to Roll manufacturing method now. Therefore, we attemped making to fabricate a flexible pressure sensor by printing and firing a piezoelectric element or a conductive ink using an inkjet apparatus or a gravure printing apparatus. However, because it was difficult to control hydrophilicity, problems such as ink staying in a dot shape and poor adhesion occurred. These problems were improved by oxygen plasma treatment that irradiates the plasma under slight oxygen gas or apply swelling type surface treatmen. Subsequently, the voltage was measured by applying pressure to the created pressure sensor. In parallel with this, printing was carried out while conveying the film by attaching the printing apparatus to the Roll to Roll apparatus, and the printing accuracy was measured.