Bio-Aerogel from KTH Royal Institute of Technology produced through air-drying method with increased wet stability and ultra-low density.


  • Scalable
  • Lightweight
  • Responsive
  • Biocompatible


  • Drug delivery
  • Soft robotics
  • Medical diagnosis

UN Sustainable Development Goals Addressed

  • Goal 3: Good Health & Wellbeing

  • Goal 9: Industry Innovation & Infrastructure


  • Cellulose
  • Alginate

The Challenge

Aerogels are lightweight, porous materials with many applications, from insulation, to oil spillage clean up, to 3D cellular scaffolds for tissue engineering. Cellulose nanofibril-based aerogels are biopolymer-based and have been studied and applied in many biomedical fields due to their unique characteristics, including ultra-light weight, high porosity, and exceptional strength. These bio-aerogels are also generally non-toxic and biodegradable. However, there is still room for improvement in the production of nanofibril-based aerogels, and aerogels generally. To produce an aerogel, the liquid within a gel must be removed without causing shrinkage. The most common method by which this is done is supercritical drying, which is energy-consuming and expensive. Moreover, substances added to some aerogels to increase the strength of the product are often not recyclable or biodegradable.

Innovation Details

The aerogel is plant-based, made of a combination of nanofibrils, alginate (a naturally occurring in seaweed), calcium carbonate, and water. It is produced through an air drying process. In this process, different weight ratios of carboxymethylated CNF gel, alginate solution, and calcium carbonate are combined to create the aerogels, which are then frozen at a standard temperature of 18 °C (64 °F), thawed, solvent exchanged, and air dried. This process is simple and scalable compared to the supercritical drying method and produces an aerogel that is ultra-low density (2 kg per cubic meter or 0.12 lb per cubic foot), highly porous (∼99% porosity), and wet-resistant.