A fully edible robot on our plate may soon become a reality

• Creation of rechargeable edible batteries using riboflavin, quercetin, and nori algae represents a significant step towards the realisation of fully functional edible robots.
• The innovative approach not only holds the potential to reduce electronic waste but also offers the possibility of novel gastronomical experiences and enhanced nutritional and medical delivery.

The convergence of robotics and food is a captivating concept that holds immense potential. Researchers from the Swiss Federal Institute of Technology (EPFL) and their EU-funded project, RoboFood, have made significant strides in bridging these two seemingly disparate domains.

The prospect of fully edible robots that could soon grace our plates is both intriguing and promising, as it presents a novel approach to addressing various challenges, from reducing electronic waste to enhancing nutritional and medical delivery.

The key to realising this vision lies in identifying the right edible materials that can mimic the functionalities of their non-edible counterparts.

“We are still figuring out which edible materials work similarly to non-edible ones,” Dario Floreano, director of the Laboratory of Intelligent Systems at EPFL and first author of the article, said.

Gelatine, for instance, can substitute rubber, while rice cookies can serve as a replacement for foam. Innovative techniques, such as the development of conductive inks containing activated carbon and Haribo gummy bears, demonstrate the versatility of edible components in creating sensors capable of perceiving pH, light, and bending.

Furthermore, the creation of rechargeable edible batteries using riboflavin, quercetin, and nori algae represents a significant step towards the realisation of fully functional edible robots.

One of the pioneering achievements in this domain is the development of the edible gripper, a gelatine-based structure that can handle an apple and be consumed afterward, as showcased by EPFL scientists in 2017.

Food and technology

The feat demonstrates the potential for edible structures to serve functional purposes while maintaining their edibility, paving the way for further integration of food and technology.

Building upon this initial breakthrough, researchers from EPFL, IIT, and the University of Bristol have taken the concept a step further by creating a conductive ink that can be sprayed on food to sense its growth.

The ink, which contains activated carbon as a conductor and Haribo gummy bears as a binder, can detect various environmental factors, such as pH, light, and bending, providing valuable insights into the growth and condition of the food.

The most recent development in the field of edible electronics is the creation of the first rechargeable edible battery by IIT researchers in 2023.

The device utilises riboflavin (vitamin B2) and quercetin (found in almonds and capers) as the battery poles, with activated carbon facilitating electron transport and nori algae, commonly used to wrap sushi, preventing short circuits.

Packaged in beeswax, this 4cm wide edible battery can operate at a safe voltage of 0.65 Volts, opening up a world of possibilities for powering various electronic devices that can be consumed alongside the food.

Edible electronics

The advancements in edible electronics extend beyond static structures and batteries, as scientists have successfully assembled partially edible robotic systems.

In 2022, researchers from EPFL and the Wageningen University designed a drone with wings made of rice cookies glued with gelatine, showcasing the potential for integrating edible components into larger mechanical systems. Similarly, EPFL and IIT scientists have created a partially edible rolling robot that utilises pneumatic gelatine legs and an edible tilt sensor, further demonstrating the versatility of this emerging field.

“Bringing robots and food together is a fascinating challenge,” Floreano said.

In 2021, Floreano joined forces with Remko Boom from Wageningen University, The Netherlands, Jonathan Rossiter from the University of Bristol, UK, and Mario Caironi from the Italian Institute of Technology, to launch the project RoboFood, funded by the EU with €3.5 million for four years.

RoboFood project

Despite these advancements, the road to a fully edible robot is not without its challenges. The lack of understanding surrounding how humans and animals perceive processed food with reactive and autonomous behaviour poses a significant hurdle.

“There is a lot of research on single edible components like actuators, sensors, and batteries,” Bokeon Kwak, a postdoc in the group of Floreano and one of the authors, said.

Additionally, the task of seamlessly integrating the electrical components, such as batteries and sensors, with the fluid-driven and pressure-based actuators remains a significant technical challenge.

Nevertheless, the researchers involved in the RoboFood project are determined to overcome these obstacles.

By addressing the technical hurdles and exploring the human and animal perception of edible robots, they aim to pave the way for a future where robotic food could become a reality.

The innovative approach not only holds the potential to reduce electronic waste but also offers the possibility of novel gastronomical experiences and enhanced nutritional and medical delivery.