Molecular switches can appear in a 1-bit binary state - in two binary modes - an active (1) or inactive (0) mode. They are also known as stimuli-responsive dyes, which can report - by color changing - different environmental influences such as water/moisture, temperature, UV-light, pH, etc. Based on this behavior, molecular switches are able to store information inside an intelligent dot code in form of zeros and ones (e.g. an analog relay). Thus, a sensor can be created, which works without any energy supply and which can be cheaply printed by means of inkjet printers.
The first step of the feasibility analysis was to examine, how stimuli-responsive dyes for screen-printing can be modified to develop an ink for piezoelectric inkjet. Second step was to examine the printability of the developed inks. A piezoelectric inkjet printer was used to realize first printings. It was done to observe how technical parameters could influence the functionality of the printed molecular switches. An intelligent dot matrix code could display where environmental influences can damage certain products such as seeds, food, electronics, pharmaceuticals and more.
In this paper, the compound characteristics of the stimuli-responsive inks and first research results of the developed molecular switches will be compared.