The ability of electronic devices to act as switches makes digital information processing possible. The current silicon-based semiconductor processors are fabricated according to a top-down principle. However, the need to scale down in the size of such electronic devices has prompted the search for molecule-based information processing components (Molecular Electronics), such as switching memories, sensors and logic gates. Concretely, within the past two decades, developments in Nanotechnology have shown the capabilities of molecules to perform some of the computational logic functions -relating to the concept of logical zeros (0) and ones (1) binary code- achieved in mainstream semiconductor technology. Molecular logic gates differ from the currently used semiconductor elements by small size, multifunctional nature and variability of input and output signals. Nonetheless, the transition of logic elements from mostly optical means for reading output signals to electronic transduction tools would be beneficial for developing many novel logic elements for information processing, (bio)sensing and actuation. Accordingly, the design, construction and miniaturization of molecular electronic systems capable of performing complex logic functions is a current challenge. Herein, 3D printing technology is presented as a promising tool to open up new horizons in the field of electronic devices in general, and molecular logic gates in particular. For this goal, a sustainable bottom-up approach has been devised for the development of the next generation of “intelligent” 3D-printed electronic devices —3D-printed responsive interfaces—, where bistable (supra)molecular switches will be electrically read out on carbon-based 3D-printed conductive substrates as the proof. This goal is in strong agreement with the EU’s digital strategy, while helping to achieve its target of a climate-neutral Europe by 2050. Accordingly, R3DINBOW entails the challenging design of a library of “intelligent” 3D-printed responsive interfaces by the incorporation of molecular and supramolecular components upon conductive carbon-based 3D-printed substrates (like 3D-nGEs) via a sustainable bottom-up approach. The discernible molecular properties between well-known bistable switchable states (0, 1) have been exploited to electrically read out the system as an EIS output signal. To this end, an innovative combination of 1) 3D printing technology, 2) Molecular Engineering Engineering, 3) Electrochemistry and 4) Green Chemistry, has been devised in order to tackle three specific research objectives (RO):
• RO1. Application of eco-friendly approaches for the fabrication of 3D-printed responsive interfaces (Months: 1–6).
• RO2. Testing & optimization of bistable (supra)molecular switches on 3D-printed responsive interfaces by EIS (Months: 5–9).
• RO3. Development of a sustainable approach for engineering metal-based 3D-printed responsive interfaces (Months: 9–13).
Consequently, R3DINBOW rises with the aim of building up the basis towards the yet undisclosed concept of molecular 3D-printed logic gates, a challenge in the Molecular Electronics field that would respond to the current needs of our Society.