Edible Electronics

Claudio Rossetti

Interview with Mario Caironi, coordinator of the Printed and Molecular Electronics research line at IIT

Mario Caironi coordinates the team of researchers at the Printed and Molecular Electronics Laboratory at the IIT centre in Milan. In recent days, the journal Advanced Materials described the prototype study of the world’s first rechargeable and edible battery made by Caironi and his team. The publication of information on the prototype has created widespread media attention in Italy and abroad, confirming once again the value of the studies carried out by IIT researchers.

Mario, you and your team developed the world’s first rechargeable, edible battery. What are the key components of this prototype and how does it feel to make something that makes us say ‘it’s the first in the world’?

It is certainly a great satisfaction because we managed to answer the question “is it possible to make this prototype?”. If we had achieved this, it was certain that we would have been the first in the world. We have hit the target, and in addition to the record, we have managed to realise an idea that we initially did not know what form it could take.

This battery is a prototype that is part of a whole series of new products in the promising field of research: edible electronics. What is it?

Edible electronic systems will be enablers of our future. The idea is to enable a series of devices that can be ingested without any side effects, because they are processed by our bodies in the same way as food is digested. We will be able to equip these devices with sensors, also made from edible materials, that can detect important data in our bodies, from temperature to the pH level in the stomach or intestines, and then also become warning devices for possible pathologies and monitor our general state of health. In addition, edible electronics can also be used in direct contact with food, and thus exploited to assess its characteristics, one of which is its state of preservation.

From a technological point of view, these devices need circuits, sensors, communication strategies and energy. The battery is essential to power these systems. We are working on making pills that, powered by our battery, can send information about our state of health to the outside world. In particular, we are developing a platform that will allow us to monitor the release of the drugs we take, receiving information on the actual ingestion of the drug, the moment a pill reaches the intestine and the timing of the release of the active ingredient.

I believe that an edible battery can create some problems for the end user who, by ingesting it, fears at least ‘getting a shock’.Surely you have remedied this problem, but how?

The battery voltage is so low that it cannot create any problems.It is little known, moreover, but our bodies are travelled by electrical signals and therefore the voltage produced by the battery is absolutely compatible with our normal functions.

On the other hand, another consideration concerns a negative reaction a person might have thinking that we want them to ingest a microchip into their body, which, by the way, already happens with ingestible electronics. In that case, the device is released from our body in the same state in which it was ingested, creating possible problems if the device gets stuck in the digestive tract, or disposal if it ends up in the sewage.

In contrast, the perspective of our work is based on devices derived from food and thus can be degraded by our bodies. The term degraded can be declined in various ways: digested, metabolised. In short, we are not using electronics to monitor our internal functions but we are using the electronic and electrical properties of food to rebuild, piece by piece, the components of electronics. In fact, the essential elements of the battery that enable us to create the voltage are two edible molecules, riboflavin and quercetin, which we already consume in large quantities.

Now your work is about to take off to the market.In which product sectors could we find your battery?

The battery was designed with an application purpose in mind.A very promising field is that of the ingestible pill, for which an application is possible with a technology transfer plan to the market. The timeframe will, however, be long because, in addition to further important technical development, since it is a medical-surgical device, various authorisations are required. I strongly believe in this prospect also because there is a strong demand from the market. Another area of great interest is that of monitoring the food we ingest and of which it is extremely important to know the characteristics from temperature, to storage, to digestion and assimilation times.

Can your work be ascribed as an example of circular economy?

Certainly yes, because we use, to create our batteries, molecules that we can extract for example from food waste, such as vegetables. We are already setting up collaborations in this direction, which will make our electronics even more sustainable.

Battery-powered cars, one of the most popular ways to reduce pollution today, produce significant problems of disposal and thus new pollution. Can your battery also be developed in the automotive field?

No, at present an edible battery cannot have the capacity to run a car. Our battery is designed to power micro systems. However, we have shown how it is possible to make a battery from materials with a very low environmental impact, and we think these results can be exploited and developed in different directions by all those who are working on research into sustainable batteries.

Your project has received support from the European Research Council. How much the issue of (scarce) funding in our country is an obstacle to research development. Is it only an economic problem or also a structural and organisational one?

The answer is complex. In absolute terms, our country should match the funding parameters that support research in other countries. The starting point for developing this analysis is to establish the total amount of resources that are made available for research. We have the advantage of being part of the European Community that allows us to participate in planned calls for proposals. Obviously, it is not a foregone conclusion to win them but we know, by following their calendar, when they will be proposed and consequently plan our activity. At the national level, calls for proposals do not follow a stable schedule and this does not allow us to organise ourselves to participate and obtain funding.

What motivation does a young person have today to pursue a job, a career, in the world of research?

The scarcity of resources also affects the recruitment of young researchers. Beyond the economic aspect, a young person must be motivated by the knowledge of the research that he or she can develop with us. I think it is very positive and gratifying to share what is initially a dream and which day after day becomes concrete until the final result is achieved, so that we can be protagonists of those changes, in some cases fortunate, that science brings to society. Ours is a beautiful, exhilarating and rewarding profession. Young people who have the privilege of being part of the great world of research cannot, however, lack the economic support that allows them to work with serenity.