Nowadays, we live in a technology-driven world. The constant use of electronic tools and objects marks our daily lives. Such electronics are still of the “traditional” kind – the type that led to the first significant studies on the subject, birthed successful companies, and highlighted issues in terms of sustainability that could be resolved through technological advancements.
Despite the growing awareness of environmental concerns, it’s evident that “traditional” electronics often do not embrace a sustainable approach. Indeed, electronic components have an end-of-life that is challenging to manage and lack trustful and well-developed recycling paths, thus becoming harmful to the environment and to humans when disposed of.
The amounts of electronic waste produced each year is growing fast – we’re talking already about millions of tons. However, the percentages of electronic waste destined for recycling are considerably lower, as a significant portion of electronic components end up in landfills or tucked away in household drawers.
However, since more than a decade, a significant “revolution” known as “green electronics” has been underway. This involves developing electronics components using bio-based and/or biodegradable materials through low energy budget procedure. An example of a material of such kind starts from cellulose.
“PLANT-E-TRONICS,” a technology developed by Ilker Bayer, Pietro Cataldi, and Athanassia Athanassiou from the IIT – Istituto Italiano di Tecnologia, can be inserted into this realm. The patent entails a composite material based on cellulose for manufacturing electronic components that are biodegradable and flexible.
This material is created by impregnating cellulose with an ink composed of protein-polymeric binders and electrically conductive nanomaterials (such as graphene nanoplatelets). It can be used in various applications, from electromagnetic shielding to antennas, photovoltaic cells, and wearable electronics.
To learn more, we posed some questions to one of the inventors of PLANT-E-TRONICS, Pietro Cataldi. This technology is also the most viewed patent in July on the Knowledge Share platform in the category of “Chemistry, Physics, New Materials, and Processing Methods.”
Could you tell us about your background and your role/interests in the research world?
I got my bachelor’s degree in physics in Genoa. I pursued my master in solid-state Physics between Genoa and Berlin, studying at the University of Genoa, the Freie Universität Berlin, and the Fritz Haber Institute der Max Plank Gesellschaft. After that, I started my Ph.D. in Genoa at the Italian Institute of Technology (IIT) and then moved to the University of Manchester and to Milan for two postdoctoral positions. In the meantime, I won a Marie Curie Individual Fellowship (project name BioConTact) and I returned to Genoa, focusing on the fellowship project that target developing biodegradable electrical conductors to be assembled as robotic skins.
Research is an ever-evolving field. During my Ph.D., I worked specifically on conductive coatings made with green inks – which is also the subject of PLANT-E-TRONICS. Over time, I transitioned and expanded my research interest to sustainable materials for electronics and robotics.
I designed and developed several conductive inks made with green solvents like water or alcohol and using biobased and/or biodegradable binders – substances that hold the ink together after the solvent evaporates. In the PLAN-E-TRONICS case, the ink was made conductive using graphene, which is well known for its exceptional physical properties.
The PLANT-E-TRONICS project: from the idea to market potential (how did you develop a technology where plants can be used for manufacturing electronic components that are biodegradable and flexible)
The idea was to use natural, readily obtainable, and biodegradable materials. We drew inspiration from nature. We used cellulose, which is the most abundant biopolymer on earth and is already largely employed by human beings. We also employed zein and aleuritic acid as sustainable binders to formulate a conductive ink.
Zein is essentially a byproduct of corn production. It is also a biodegradable protein with remarkable adhesive properties. As such, we used it in our ink. Aleuritic acid is a biodegradable material similar to plant-produced resins and has good adhesive properties. Therefore, the final version of the developed binder consisted of a mixture of zein and aleuritic acid to obtain the best processability and adhesion properties.
How does it work and how does it improve the current status quo of existing technologies (if there are any)?
The idea behind “green electronics” is to use materials that are as sustainable as possible. This entails using minimal energy for production, nontoxic solvents for humans and the environment, and partially or fully biodegradable materials. This patent involves producing inks with non-hazardous ingredients that can be coated preferentially on cellulose, obtaining a flexible electrical conductor that can biodegrade at the end of its lifecycle. The bulk of the material we develop is cellulose, while less than 5% is the non-biodegradable part – in this case, graphene.
The ink is sprayed onto substrates and then utilized for various purposes. For example, we employed conductive materials as an electrode for a solar cell. We also developed an antenna and demonstrated the electromagnetic shielding properties of our material.
Research on “green electronics” is acquiring worldwide interest. Many prominent institutions are contributing on this important topic. In Italy the interest is high too. We’re engaged in this topic at IIT in Genoa in the group of Dr. Athanassia Athanassiou, where I currently work, as well as in IIT in Milan in the group of Mario Caironi. Overall, many teams are active in Italy on such topic. To mention a few names, Dr. Luisa Petti and Dr. Paolo Lugli from the Free University of Bozen-Bolzano, Dr. Giuseppe Cantarella from the University of Modena and Reggio Emilia, and Dr. Luisa Torsi from the University of Bari.
Progress of the project up to now and plans for the future, what are you aiming for? In which of the applications (electromagnetic shielding, photovoltaic cells, wearable
electronics) is there greater demand?
Despite being around for about a decade, green electronics is still in its infancy. Replacing “traditional” electronics developed over several decades, such as the ones in smartphones, with green alternatives is quite far. Instead, creating new applications that are not made with conventional electronics is more promising. Consider niche applications that would gradually become more widespread over the years. For example, consider sensors for environmental monitoring that could naturally degrade in the environment at their end of use. Consider bioresorbable or edible electronics that may be implanted or eaten to perform their function, such as monitoring specific parameters of the body, and then dissolve or be digested when they accomplish their task. Lastly, think about soft robots with unique properties, such as being safe, low-cost, and lightweight, and that can be implemented into high-performing robot grippers for agriculture, prostheses, and next-generation wearables devices.
All the applications mentioned above will significantly advance with the progress of green electronics and cannot be performed efficiently or safely with existing “traditional” electronics.
Supplanting is complex, but creating applications where traditional electronics cannot compete can lead to more effective and successful market integration.
Spinoff or not – spinoff? If not, why? If yes, with whom? (Investors / industrial partners?) How much funding would it require?
I had considered making a startup during my Ph.D., but I wanted to continue with academia because I like it. Doing both things simultaneously is challenging, especially if you are not permanent or tenured yet. There are many spin-offs within IIT, and many others have become companies. Smart Materials laboratory, where I work, is creating a company that produces innovative plastics from paper residues in collaboration with several well-known established companies in the national and international arena.
In the episode of Smart Cities on Radio24 from Sole24Ore, Maurizio Melis interviews Andrea Monti – a professor from the Department of Agri-Food Sciences and Technologies at the University of Bologna – regarding camellia and carinata: two new species identified as intercropping crops that can aid in the energy transition, for example, by producing bio-based products. In your case, which biomasses can be referred to? Or what would you need?
The materials for creating green electronics are indeed often bio-based, as the one indicated by Prof. Andrea Monti. There are numerous materials that nature can offer. Our approach is to identify which fits best for your intended application. Indeed, biobased, and biodegradable materials have an extensive range of features so that different materials may fit for different applications. Then, I give additional features or empower the starting selected material by making composites (i.e., blending with other materials). If all the materials employed are biobased and/or biodegradable, the resulting material is also biobased, and there is a high chance that it will also be biodegradable.
Italy and the National Recovery and Resilience Plan (PNRR), as well as other projects: how does Italy respond from social, economic, and political perspectives to green chemistry?
The PNRR is a significant chance, and substantial funding is involved. It is an opportunity with numerous challenges that need to be addressed. One of these challenges is that research in Italy has been accustomed to operating at a resource level of “X” for many years. However, suddenly, it must operate at a resource level exponentially higher. So, there is a need to bring in many talented people from abroad to implement all the research projects coming from PNRR funding successfully. Generally, Italian research is attracting few international researchers. So, this is one of the main challenges. Moreover, PNRR needs to be implemented within a defined timeframe. This makes things more challenging. However, overall, PNRR is fantastic, and it is interesting to note that the landscape of Italian research is becoming more attractive and competitive with it, which can only bring positive outcomes.
Another positive aspect of the PNRR is that it has provided resources to establish annual competitive grants organized by the Fondo Italiano per la Scienza for researchers who want to work in Italian institutions. Having these funds and knowing that one can compete for research grants yearly is amazing. Ensuring that this kind of investment in research continues and grows even after the PNRR ends in 2026 is equally essential. I hope that such a fund scheme will survive PNRR. This can happen through a long-term investment and vision for the research in Italy.
To learn more about PLANT-E-TRONICS: ‘PLANT-e-TRONICS’: ‘PLANT-e-TRONICS’: ‘PLANT-e-TRONICS’: ELECTRICALLY CONDUCTIVE CELLULOSE-BASED COMPOSITE MATERIALS | Knowledgeshare (knowledge-share.eu)