Abstract:

Printed electronics are electronic devices that are completely or partially made by printing processes [1]. These devices are getting more and more established in our daily life. There are already RFID-chips or touch-screens that can be printed [1,2]. Conductible layers can be printed one over another to either transfer data or make devices emit light. Devices that are developed this way can be very thin and also flexible [2].

The technical printing process of one that emits light was transferred into a hands-on experiment for science teaching and afterwards accompanying learning material was developed. Within the experiment different layers are applied on a conductive substrate one after the other. The core element of the hand-printed EL (electroluminescence)-foil is a paste, based on doped zinc sulfide, which functions as a semiconductor. When you apply voltage to the device one can detect bright blue luminescence. There are three more layers next to the semiconductor paste that are needed to complete the device. It can be imagined as a sandwich where two electrodes provide the framework for the semiconductor and an insulating layer. For conducting the device, a spot of conductive silver ink is put on the surface. The different layers are dried and cured in different ways.

In the presentation the different hands-on steps will be shown in a short time-lapse video. Moreover, the last step will be shown in presence and the device will be applied to voltage to show its function. In addition to that, the accompanying material will be presented within the structure of a possible teaching unit to show in which way the didactics transforms current research and development into experiments for science teaching purpose. Finally, results of the first uses of the teaching unit are presented, with the focus on the opinion of the learners.

References:
[1] M. Schewe, H. Rost, Kunststoffe, 2012, 101(10), 38-42.
[2] S. I. Verstraelen, K. Hecker, 2019, https://www.chemanager-online.com/themen/chemikalien-distribution/gedruckte-elektronik-ist-im-alltag-angekommen

Keywords:

Curriculum Innovation, Electroluminescence, Hands-on Experiment.