Edible shock- and heat-resistant wood foam could replace plastic packaging

Researchers at Aalto University are developing wood-based foam materials with the help of artificial intelligence in their Smart Foams research project. The project got funding for research into foams from the Technology Industries of Finland Centennial Foundation and the Jane and Aatos Erkko Foundation, while a grant from Business Finland is helping commercialise the foam innovation. The total budget of the project is just under a million euros.

The research group has been studying foam for about ten years. In recent years, researchers have been interested in replacing plastic with wood-based materials; which have cell structures that provide strength and good heat insulation.

‘The project is based on biomimetics, which replicates natural phenomena. With the help of artificial intelligence, we are trying to develop a foam with wood-like features, such as strength, flexibility, and heat resistance’, says Professor Mikko Alava.

In the project funded by the foundations, the researchers are seeking to optimise the features of the foam. For example, a mixture of the compounds lignin, wood fibre, and laponite can produce a foam that resists shock and humidity and can be used to replace plastic. Lignin is a binder of wood fibres and when it is made into a dried foam it is hard, water-resistant, and even conducts electricity.

‘Traditional material development is slow and unpredictable, and new materials may even have emerged by accident, as was the case with Teflon. In this project we utilise machine learning, with which we can exclude superfluous combinations of materials and processes and considerably accelerate development work’, says postdoctoral researcher Juha Koivisto.

Foams can also be produced using different technologies. Web formation, or paper manufacture technology, produces material with exactly the right thickness, but the wet foam dries slowly. Extrusion, or 3D printing, produces hard and long bubbles which make the structure stick-like and strong.

‘Artificial intelligence uses previous data to show us how to add a desired feature with less effort’, Koivisto says.

Light and edible

With funding from Business Finland, the researchers are looking for commercial applications and markets for the new material.

‘Commercialisation and the replacement of Styrofoam and bubble wrap, for example, in packaging require that the bio-based material really is biodegradable, cheap, and can be produced in massive quantities. In some applications, it also needs to resist humidity’, Alava says.

Because of its lightness, its heat insulation properties, and its strength, the foam material can be used for insulation in buildings if it is both resistant to humidity and fire safe. Research continues into this. The foam material is remarkably similar to cork, for example, and is also tens of times lighter.

‘Fibre can be manufactured from other materials, including carbon. The geometric features of the fibre are significant in the material, enabling the modification of the features of the material that is to be manufactured. Spiky fibres produce better foam than materials with a powder-like texture. The goal of material optimisation is to produce extraordinarily strong and light materials that are also environmentally friendly’, says postdoctoral researcher Antti Puisto.

‘The most extraordinary feature of the foam is that it is edible. The method makes it possible to produce foam from carrot, lingonberry, cranberry, or beetroot powder, and make chips out of them similar to potato crisps’, Koivisto says.

The research group has extensive skills and knowledge in forest-based materials, foams, and in the use of artificial intelligence in materials research. Design and planning of packaging are the responsibility of Luisa Jannuzzi, who has a Master of Arts degree from the Creative Sustainability programme, and who has studied the use of cellulose-based materials as packaging material.

"The packaging material is fully bio-based, it biodegrades in natural conditions and it is easily recyclable with cardboard", says Jannuzzi.

The Smart Foams research project involves the Aalto University Complex Systems and Materials (CSM) group, which is part of FinnCERES, a competence centre of Aalto University and VTT Technical Research Centre of Finland on the bioeconomy of materials. The goal of FinnCERES is to develop bioeconomy materials using wood as a raw material to promote a sustainable future to protect the environment. Further information is available at the competence centre's website.