Thesis defence in the University of Oulu

Doctoral Candidate

Master of Science Pauliina Vilmi

Faculty and research unit

University of Oulu Graduate School, Faculty of Information Technology and Electrical Engineering, Optoelectronics and Measurement Techniques

Field of study

Electrical Engineering

Date and time of the thesis defence

26.2.2021 12:00

Place of the thesis defence

Remote connection: : https://oulu.zoom.us/j/62238685448

Topic of the dissertation

Component fabrication by printing methods for optics and electronics applications

Opponent

Docent Jukka Hast, VTT

Custos

Professor Tapio Fabritius, University of Oulu

Component fabrication by printing methods for optics and electronics applications

This thesis investigates how printing methods can be used to fabricate components for optics and electronics applications. Three different components were chosen, in order to demonstrate the technology’s versatility: a microlens array, a memristor and a double-sided capacitive sensor. While the work focused on design and fabrication aspects, the components’ functionality was also verified through appropriate methods. Polymer microlens arrays were fabricated by inkjet printing on different substrates, and their physical characteristics were inspected. After additional investigation, the lens array fabricated on a glass substrate was determined to have imaging quality equal to the commercial glass reference, thus becoming a viable cost-effective alternative to an expensive glass lens array.

The memristors were fabricated solely through inkjet printing. The fabricated an active layer printed between two silver electrodes. The physical and electrical properties of the fabricated samples were characterized. The memristivity of the component was proven functional, making the memristor one of the first fully inkjet printed ones. The third component was a screen-printed double-sided capacitive sensor. It was fabricated on an air filter to monitor the filter’s dirtiness level. The increasing dirtiness of a filter decreases the air flow requiring a filter replacement. The studies showed a correlation between the measurements results and filter dirtiness, making the sensor element a possible device for filter observation. The obtained results and implemented components exemplify the great potential and variety of printed intelligence in many fields of research, and their eventual impact on our everyday life.

Dissertation

Last updated: 22.2.2021